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diff --git a/docs/doc/under.html b/docs/doc/under.html index 4ec761a8..df79f48c 100644 --- a/docs/doc/under.html +++ b/docs/doc/under.html @@ -82,7 +82,7 @@ <h2 id="computational-under"><a class="header" href="#computational-under">Computational Under</a></h2> <p>Computational Under is based on <a href="undo.html">Undo</a> (<code><span class='Modifier'>⁼</span></code>), and applies whenever structural Under doesn't. It's still limited, because Undo doesn't work on many or even most functions. One common use is with the square function <code><span class='Function'>×</span><span class='Modifier'>˜</span></code>, for computations such as finding the magnitude of a vector, or a <a href="https://en.wikipedia.org/wiki/Root_mean_square">root-mean-square</a> average like the one below.</p> <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=KCvCtMO34omgKeKMvijDl8ucKSAy4oC/M+KAvzTigL81">↗️</a><pre> <span class='Paren'>(</span><span class='Function'>+</span><span class='Modifier'>´</span><span class='Function'>÷≠</span><span class='Paren'>)</span><span class='Modifier2'>⌾</span><span class='Paren'>(</span><span class='Function'>×</span><span class='Modifier'>˜</span><span class='Paren'>)</span> <span class='Number'>2</span><span class='Ligature'>‿</span><span class='Number'>3</span><span class='Ligature'>‿</span><span class='Number'>4</span><span class='Ligature'>‿</span><span class='Number'>5</span> -3.674234614174767 +3.6742346141747673 </pre> <p>This average is the square root of the average of the squares of the arguments, and <code><span class='Modifier2'>⌾</span></code> lets us combine the two square-y steps. Here there are two possible solutions because <code><span class='Number'>¯3.67</span><span class='Value'>…</span></code> has the same square as the positive result; BQN of course uses the principal root. Similarly, <code><span class='Modifier2'>⌾</span><span class='Function'>÷</span></code> can be used for a harmonic sum or mean (you might notice that computational Under is a lot more mathy than the structural one).</p> <p>Under is the idiomatic way to do a round-to-nearest function:</p> |