<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>module Silicium::Optimization - RDoc Documentation</title>
<script type="text/javascript">
var rdoc_rel_prefix = "../";
var index_rel_prefix = "../";
</script>
<script src="../js/navigation.js" defer></script>
<script src="../js/search.js" defer></script>
<script src="../js/search_index.js" defer></script>
<script src="../js/searcher.js" defer></script>
<script src="../js/darkfish.js" defer></script>
<link href="../css/fonts.css" rel="stylesheet">
<link href="../css/rdoc.css" rel="stylesheet">
<body id="top" role="document" class="module">
<nav role="navigation">
<div id="project-navigation">
<div id="home-section" role="region" title="Quick navigation" class="nav-section">
<h2>
<a href="../index.html" rel="home">Home</a>
</h2>
<div id="table-of-contents-navigation">
<a href="../table_of_contents.html#pages">Pages</a>
<a href="../table_of_contents.html#classes">Classes</a>
<a href="../table_of_contents.html#methods">Methods</a>
</div>
</div>
<div id="search-section" role="search" class="project-section initially-hidden">
<form action="#" method="get" accept-charset="utf-8">
<div id="search-field-wrapper">
<input id="search-field" role="combobox" aria-label="Search"
aria-autocomplete="list" aria-controls="search-results"
type="text" name="search" placeholder="Search" spellcheck="false"
title="Type to search, Up and Down to navigate, Enter to load">
</div>
<ul id="search-results" aria-label="Search Results"
aria-busy="false" aria-expanded="false"
aria-atomic="false" class="initially-hidden"></ul>
</form>
</div>
</div>
<div id="class-metadata">
<!-- Method Quickref -->
<div id="method-list-section" class="nav-section">
<h3>Methods</h3>
<ul class="link-list" role="directory">
<li ><a href="#method-i-accuracy">#accuracy</a>
<li ><a href="#method-i-bogosort">#bogosort</a>
<li ><a href="#method-i-bogosort-21">#bogosort!</a>
<li ><a href="#method-i-half_division">#half_division</a>
<li ><a href="#method-i-half_division_step">#half_division_step</a>
<li ><a href="#method-i-hook_jeeves">#hook_jeeves</a>
<li ><a href="#method-i-hook_jeeves_step">#hook_jeeves_step</a>
<li ><a href="#method-i-integrating_Monte_Carlo_base">#integrating_Monte_Carlo_base</a>
<li ><a href="#method-i-middle">#middle</a>
<li ><a href="#method-i-re_lu">#re_lu</a>
<li ><a href="#method-i-sigmoid">#sigmoid</a>
<li ><a href="#method-i-sorted-3F">#sorted?</a>
<li ><a href="#method-i-switch_step">#switch_step</a>
</ul>
</div>
</div>
</nav>
<main role="main" aria-labelledby="module-Silicium::Optimization">
<h1 id="module-Silicium::Optimization" class="module">
module Silicium::Optimization
</h1>
<section class="description">
</section>
<section id="5Buntitled-5D" class="documentation-section">
<section id="public-instance-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Public Instance Methods</h3>
</header>
<div id="method-i-accuracy" class="method-detail ">
<div class="method-heading">
<span class="method-name">accuracy</span><span
class="method-args">(step)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>calculate current accuracy in Hook - Jeeves method</p>
<div class="method-source-code" id="accuracy-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 64</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">accuracy</span>(<span class="ruby-identifier">step</span>)
<span class="ruby-identifier">acc</span> = <span class="ruby-value">0</span>
<span class="ruby-identifier">step</span>.<span class="ruby-identifier">each</span> { <span class="ruby-operator">|</span><span class="ruby-identifier">a</span><span class="ruby-operator">|</span> <span class="ruby-identifier">acc</span> <span class="ruby-operator">+=</span> <span class="ruby-identifier">a</span> <span class="ruby-operator">*</span> <span class="ruby-identifier">a</span> }
<span class="ruby-constant">Math</span>.<span class="ruby-identifier">sqrt</span>(<span class="ruby-identifier">acc</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-bogosort" class="method-detail ">
<div class="method-heading">
<span class="method-name">bogosort</span><span
class="method-args">(a)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>fastest(but it is not exactly) sort</p>
<div class="method-source-code" id="bogosort-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 52</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">bogosort</span>(<span class="ruby-identifier">a</span>)
<span class="ruby-keyword">if</span> (<span class="ruby-identifier">a</span>.<span class="ruby-identifier">nil?</span>)
<span class="ruby-identifier">raise</span> <span class="ruby-constant">ArgumentError</span>, <span class="ruby-string">"Nil array in bogosort"</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">crutch</span> = <span class="ruby-identifier">a</span>
<span class="ruby-keyword">while</span> (<span class="ruby-operator">!</span><span class="ruby-identifier">sorted?</span>(<span class="ruby-identifier">crutch</span>))
<span class="ruby-identifier">crutch</span> = <span class="ruby-identifier">a</span>.<span class="ruby-identifier">shuffle</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">crutch</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-bogosort-21" class="method-detail ">
<div class="method-heading">
<span class="method-name">bogosort!</span><span
class="method-args">(a)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>fastest(but it is not exactly) sort, modify sequance</p>
<div class="method-source-code" id="bogosort-21-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 41</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">bogosort!</span>(<span class="ruby-identifier">a</span>)
<span class="ruby-keyword">if</span> (<span class="ruby-identifier">a</span>.<span class="ruby-identifier">nil?</span>)
<span class="ruby-identifier">raise</span> <span class="ruby-constant">ArgumentError</span>, <span class="ruby-string">"Nil array in bogosort"</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">while</span> (<span class="ruby-operator">!</span><span class="ruby-identifier">sorted?</span>(<span class="ruby-identifier">a</span>))
<span class="ruby-identifier">a</span>.<span class="ruby-identifier">shuffle!</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">a</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-half_division" class="method-detail ">
<div class="method-heading">
<span class="method-name">half_division</span><span
class="method-args">(a, b, eps = 0.001, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>find root in [a, b], if he exist, if number of iterations > iters -> error</p>
<div class="method-source-code" id="half_division-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 126</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">half_division</span>(<span class="ruby-identifier">a</span>, <span class="ruby-identifier">b</span>, <span class="ruby-identifier">eps</span> = <span class="ruby-value">0.001</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-identifier">iters</span> = <span class="ruby-value">1000000</span>
<span class="ruby-identifier">c</span> = <span class="ruby-identifier">middle</span>(<span class="ruby-identifier">a</span>, <span class="ruby-identifier">b</span>)
<span class="ruby-keyword">while</span> ((<span class="ruby-identifier">block</span>.<span class="ruby-identifier">call</span>(<span class="ruby-identifier">c</span>).<span class="ruby-identifier">abs</span>) <span class="ruby-operator">></span> <span class="ruby-identifier">eps</span>)
<span class="ruby-identifier">tmp</span> = <span class="ruby-identifier">half_division_step</span>(<span class="ruby-identifier">a</span>, <span class="ruby-identifier">b</span>, <span class="ruby-identifier">c</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-identifier">a</span> = <span class="ruby-identifier">tmp</span>[<span class="ruby-value">0</span>]
<span class="ruby-identifier">b</span> = <span class="ruby-identifier">tmp</span>[<span class="ruby-value">1</span>]
<span class="ruby-identifier">c</span> = <span class="ruby-identifier">tmp</span>[<span class="ruby-value">2</span>]
<span class="ruby-identifier">iters</span> <span class="ruby-operator">-=</span> <span class="ruby-value">1</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">iters</span> <span class="ruby-operator">==</span> <span class="ruby-value">0</span>
<span class="ruby-identifier">raise</span> <span class="ruby-constant">RuntimeError</span>, <span class="ruby-string">"Root not found! Check does he exist, or change eps or iters"</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">c</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-half_division_step" class="method-detail ">
<div class="method-heading">
<span class="method-name">half_division_step</span><span
class="method-args">(a, b, c, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>do one half division step</p>
<div class="method-source-code" id="half_division_step-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 114</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">half_division_step</span>(<span class="ruby-identifier">a</span>, <span class="ruby-identifier">b</span>, <span class="ruby-identifier">c</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> (<span class="ruby-identifier">block</span>.<span class="ruby-identifier">call</span>(<span class="ruby-identifier">a</span>) <span class="ruby-operator">*</span> <span class="ruby-identifier">block</span>.<span class="ruby-identifier">call</span>(<span class="ruby-identifier">c</span>) <span class="ruby-operator"><</span> <span class="ruby-value">0</span>)
<span class="ruby-identifier">b</span> = <span class="ruby-identifier">c</span>
<span class="ruby-identifier">c</span> = <span class="ruby-identifier">middle</span>(<span class="ruby-identifier">a</span>, <span class="ruby-identifier">c</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">a</span> = <span class="ruby-identifier">c</span>
<span class="ruby-identifier">c</span> = <span class="ruby-identifier">middle</span>(<span class="ruby-identifier">b</span>, <span class="ruby-identifier">c</span>)
<span class="ruby-keyword">end</span>
[<span class="ruby-identifier">a</span>, <span class="ruby-identifier">b</span>, <span class="ruby-identifier">c</span>]
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-hook_jeeves" class="method-detail ">
<div class="method-heading">
<span class="method-name">hook_jeeves</span><span
class="method-args">(x, step, eps = 0.1, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Hook - Jeeves method for find minimum point (x - array of start variables, step - step of one iteration, eps - allowable error, alfa - slowdown of step, block - function which takes array x, WAENING function doesn't control correctness of input</p>
<div class="method-source-code" id="hook_jeeves-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 92</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">hook_jeeves</span>(<span class="ruby-identifier">x</span>, <span class="ruby-identifier">step</span>, <span class="ruby-identifier">eps</span> = <span class="ruby-value">0.1</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-identifier">prev_f</span> = <span class="ruby-identifier">block</span>.<span class="ruby-identifier">call</span>(<span class="ruby-identifier">x</span>)
<span class="ruby-identifier">acc</span> = <span class="ruby-identifier">accuracy</span>(<span class="ruby-identifier">step</span>)
<span class="ruby-keyword">while</span> (<span class="ruby-identifier">acc</span> <span class="ruby-operator">></span> <span class="ruby-identifier">eps</span>)
<span class="ruby-keyword">for</span> <span class="ruby-identifier">i</span> <span class="ruby-keyword">in</span> <span class="ruby-value">0</span><span class="ruby-operator">..</span><span class="ruby-identifier">x</span>.<span class="ruby-identifier">length</span> <span class="ruby-operator">-</span> <span class="ruby-value">1</span>
<span class="ruby-identifier">tmp</span> = <span class="ruby-identifier">hook_jeeves_step</span>(<span class="ruby-identifier">x</span>, <span class="ruby-identifier">i</span>, <span class="ruby-identifier">step</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-identifier">cur_f</span> = <span class="ruby-identifier">tmp</span>[<span class="ruby-value">0</span>]
<span class="ruby-identifier">x</span>[<span class="ruby-identifier">i</span>] = <span class="ruby-identifier">tmp</span>[<span class="ruby-value">1</span>]
<span class="ruby-identifier">step</span>[<span class="ruby-identifier">i</span>] = <span class="ruby-identifier">switch_step</span>(<span class="ruby-identifier">cur_f</span>, <span class="ruby-identifier">prev_f</span>, <span class="ruby-identifier">step</span>, <span class="ruby-identifier">i</span>)
<span class="ruby-identifier">prev_f</span> = <span class="ruby-identifier">cur_f</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">acc</span> = <span class="ruby-identifier">accuracy</span>(<span class="ruby-identifier">step</span>)
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">x</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-hook_jeeves_step" class="method-detail ">
<div class="method-heading">
<span class="method-name">hook_jeeves_step</span><span
class="method-args">(x, i, step, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>do one Hook - Jeeves step</p>
<div class="method-source-code" id="hook_jeeves_step-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 71</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">hook_jeeves_step</span>(<span class="ruby-identifier">x</span>, <span class="ruby-identifier">i</span>, <span class="ruby-identifier">step</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-identifier">x</span>[<span class="ruby-identifier">i</span>] <span class="ruby-operator">+=</span> <span class="ruby-identifier">step</span>[<span class="ruby-identifier">i</span>]
<span class="ruby-identifier">tmp1</span> = <span class="ruby-identifier">block</span>.<span class="ruby-identifier">call</span>(<span class="ruby-identifier">x</span>)
<span class="ruby-identifier">x</span>[<span class="ruby-identifier">i</span>] = <span class="ruby-identifier">x</span>[<span class="ruby-identifier">i</span>] <span class="ruby-operator">-</span> <span class="ruby-value">2</span> <span class="ruby-operator">*</span> <span class="ruby-identifier">step</span>[<span class="ruby-identifier">i</span>]
<span class="ruby-identifier">tmp2</span> = <span class="ruby-identifier">block</span>.<span class="ruby-identifier">call</span>(<span class="ruby-identifier">x</span>)
<span class="ruby-keyword">if</span> (<span class="ruby-identifier">tmp1</span> <span class="ruby-operator">></span> <span class="ruby-identifier">tmp2</span>)
<span class="ruby-identifier">cur_f</span> = <span class="ruby-identifier">tmp2</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">x</span>[<span class="ruby-identifier">i</span>] = <span class="ruby-identifier">x</span>[<span class="ruby-identifier">i</span>] <span class="ruby-operator">+</span> <span class="ruby-identifier">step</span>[<span class="ruby-identifier">i</span>] <span class="ruby-operator">*</span> <span class="ruby-value">2</span>
<span class="ruby-identifier">cur_f</span> = <span class="ruby-identifier">tmp1</span>
<span class="ruby-keyword">end</span>
[<span class="ruby-identifier">cur_f</span>, <span class="ruby-identifier">x</span>[<span class="ruby-identifier">i</span>]]
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-integrating_Monte_Carlo_base" class="method-detail ">
<div class="method-heading">
<span class="method-name">integrating_Monte_Carlo_base</span><span
class="method-args">(a, b, n = 100000, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>integrating using method Monte Carlo (f - function, a, b - integrating limits, n - amount of random numbers)</p>
<div class="method-source-code" id="integrating_Monte_Carlo_base-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 19</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">integrating_Monte_Carlo_base</span>(<span class="ruby-identifier">a</span>, <span class="ruby-identifier">b</span>, <span class="ruby-identifier">n</span> = <span class="ruby-value">100000</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-identifier">res</span> = <span class="ruby-value">0</span>
<span class="ruby-identifier">range</span> = <span class="ruby-identifier">a</span><span class="ruby-operator">..</span><span class="ruby-identifier">b</span>.<span class="ruby-identifier">to_f</span>
<span class="ruby-keyword">for</span> <span class="ruby-identifier">i</span> <span class="ruby-keyword">in</span> <span class="ruby-value">1</span><span class="ruby-operator">..</span>(<span class="ruby-identifier">n</span> <span class="ruby-operator">+</span> <span class="ruby-value">1</span>)
<span class="ruby-identifier">x</span> = <span class="ruby-identifier">rand</span>(<span class="ruby-identifier">range</span>)
<span class="ruby-identifier">res</span> <span class="ruby-operator">+=</span> (<span class="ruby-identifier">b</span> <span class="ruby-operator">-</span> <span class="ruby-identifier">a</span>) <span class="ruby-operator">*</span> <span class="ruby-value">1.0</span> <span class="ruby-operator">/</span> <span class="ruby-identifier">n</span> <span class="ruby-operator">*</span> <span class="ruby-identifier">block</span>.<span class="ruby-identifier">call</span>(<span class="ruby-identifier">x</span>)
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">res</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-middle" class="method-detail ">
<div class="method-heading">
<span class="method-name">middle</span><span
class="method-args">(a, b)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>find centr of interval</p>
<div class="method-source-code" id="middle-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 109</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">middle</span>(<span class="ruby-identifier">a</span>, <span class="ruby-identifier">b</span>)
(<span class="ruby-identifier">a</span> <span class="ruby-operator">+</span> <span class="ruby-identifier">b</span>) <span class="ruby-operator">/</span> <span class="ruby-value">2.0</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-re_lu" class="method-detail ">
<div class="method-heading">
<span class="method-name">re_lu</span><span
class="method-args">(x)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>reflector function</p>
<div class="method-source-code" id="re_lu-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 9</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">re_lu</span>(<span class="ruby-identifier">x</span>)
<span class="ruby-identifier">x</span>.<span class="ruby-identifier">negative?</span> <span class="ruby-operator">?</span> <span class="ruby-value">0</span> <span class="ruby-operator">:</span> <span class="ruby-identifier">x</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-sigmoid" class="method-detail ">
<div class="method-heading">
<span class="method-name">sigmoid</span><span
class="method-args">(x)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>sigmoid function</p>
<div class="method-source-code" id="sigmoid-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 14</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">sigmoid</span>(<span class="ruby-identifier">x</span>)
<span class="ruby-value">1.0</span> <span class="ruby-operator">/</span> (<span class="ruby-value">1</span> <span class="ruby-operator">+</span> <span class="ruby-constant">Math</span>.<span class="ruby-identifier">exp</span>(<span class="ruby-operator">-</span><span class="ruby-identifier">x</span>))
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-sorted-3F" class="method-detail ">
<div class="method-heading">
<span class="method-name">sorted?</span><span
class="method-args">(a)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>return true if array is sorted</p>
<div class="method-source-code" id="sorted-3F-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 30</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">sorted?</span>(<span class="ruby-identifier">a</span>)
<span class="ruby-keyword">return</span> <span class="ruby-keyword">false</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">a</span>.<span class="ruby-identifier">nil?</span>
<span class="ruby-keyword">for</span> <span class="ruby-identifier">i</span> <span class="ruby-keyword">in</span> <span class="ruby-value">0</span><span class="ruby-operator">..</span><span class="ruby-identifier">a</span>.<span class="ruby-identifier">length</span> <span class="ruby-operator">-</span> <span class="ruby-value">2</span>
<span class="ruby-keyword">if</span> (<span class="ruby-identifier">a</span>[<span class="ruby-identifier">i</span> <span class="ruby-operator">+</span> <span class="ruby-value">1</span>] <span class="ruby-operator"><</span> <span class="ruby-identifier">a</span>[<span class="ruby-identifier">i</span>])
<span class="ruby-keyword">return</span> <span class="ruby-keyword">false</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">true</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-switch_step" class="method-detail ">
<div class="method-heading">
<span class="method-name">switch_step</span><span
class="method-args">(cur_f, prev_f, step, i)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>switch step if current func value > previous func value</p>
<div class="method-source-code" id="switch_step-source">
<pre><span class="ruby-comment"># File lib/optimization.rb, line 86</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">switch_step</span>(<span class="ruby-identifier">cur_f</span>, <span class="ruby-identifier">prev_f</span>, <span class="ruby-identifier">step</span>, <span class="ruby-identifier">i</span>)
<span class="ruby-keyword">return</span> <span class="ruby-identifier">step</span>[<span class="ruby-identifier">i</span>] <span class="ruby-operator">/</span> <span class="ruby-value">2.0</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">cur_f</span> <span class="ruby-operator">>=</span> <span class="ruby-identifier">prev_f</span> <span class="ruby-comment">#you can switch 2.0 on something else</span>
<span class="ruby-identifier">step</span>[<span class="ruby-identifier">i</span>]
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
</section>
</section>
</main>
<footer id="validator-badges" role="contentinfo">
<p><a href="https://validator.w3.org/check/referer">Validate</a>
<p>Generated by <a href="https://ruby.github.io/rdoc/">RDoc</a> 6.2.0.
<p>Based on <a href="http://deveiate.org/projects/Darkfish-RDoc/">Darkfish</a> by <a href="http://deveiate.org">Michael Granger</a>.
</footer>