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  1. PO
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    <p>Your fiddle link wasn't working for me due to a missing interval speed, should be using <code>getElementById</code> too (<strong>just because it works in Internet Explorer doesn't make it cross-browser</strong>).</p> <p>Here, I forked it, use this one instead:</p> <p><a href="http://jsfiddle.net/spechackers/hJhCz/" rel="noreferrer">http://jsfiddle.net/spechackers/hJhCz/</a></p> <p>I have also cleaned up the code in your first link:</p> <pre><code>&lt;pre id="p"&gt; &lt;script type="text/javascript"&gt; var charMap=['p','.']; var n=0; function myInterval() { n+=7;//this is the amount of screen to "scroll" per interval var outString=""; //this loop will execute exactly 4096 times. Once for each character we will be working with. //Our display screen will consist of 32 lines or rows and 128 characters on each line for(var i=64; i&gt;0; i-=1/64) { //Note mod operations can result in numbers like 1.984375 if working with non-integer numbers like we currently are var mod2=i%2; if(mod2==0) { outString+="\n"; }else{ var tmp=(mod2*(64/i))-(64/i);//a number between 0.9846153846153847 and -4032 tmp=tmp+(n/64);//still working with floating points. tmp=tmp^(64/i);//this is a bitwise XOR operation. The result will always be an integer tmp=tmp&amp;1;//this is a bitwise AND operation. Basically we just want to know if the first bit is a 1 or 0. outString+=charMap[tmp]; } }//for document.getElementById("p").innerHTML=outString; } myInterval(); setInterval(myInterval,64); &lt;/script&gt; &lt;/pre&gt; </code></pre> <p>The result of the code in the two links you provided are very different from one another. However the logic in the code is quite similar. Both use a for-loop to loop through all the characters, a mod operation on a non-integer number, and a <code>bitwise</code> xor operation.</p> <p>How does it all work, well basically all <code>I can tell you is to pay attention to the variables changing as the input and output change</code>. </p> <p>All the logic appears to be some sort of <code>bitwise</code> cryptic way to decide which of 2 characters or a line break to add to the page.</p> <p>I don't quite follow it myself from a <code>calculus or trigonometry</code> sort of perspective.</p>
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    1. POWhat is the math behind this ray-like animation?
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    1. POWhat is the math behind this ray-like animation?
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    1. COone question. In the if statement (mod2 == 0) I see that you are doing this `var tmp=(mod2*(64/i))-(64/i)` (in the else clause). But do we need to multiply by mod2 (which will equal to 1)?
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      1. USParth Thakkar
    2. CO@ParthThakkar: In the code it says, `Note, mod operations can result in numbers like 1.984375 if working with non-integer numbers like we currently are`.
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    3. COall right! missed that...usually, loops have always been all-integers for me...it just slipped out my mind.
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