| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `rand_distr/src/cauchy.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>cauchy.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" type="text/css" href="../../normalize.css"><link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../ayu.css" disabled><link rel="stylesheet" type="text/css" href="../../dark.css" disabled><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script src="../../crates.js"></script><script defer src="../../main.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script> |
| <noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="shortcut icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu" role="button">☰</div><a class="sidebar-logo" href="../../rand_distr/index.html"><div class="logo-container"><img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></div> |
| </a></nav><main><div class="width-limiter"><div class="sub-container"><a class="sub-logo-container" href="../../rand_distr/index.html"><img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><nav class="sub"><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu" title="themes"><img width="18" height="18" alt="Pick another theme!" src="../../brush.svg"></button><div id="theme-choices" role="menu"></div></div><form class="search-form"><div class="search-container"><div> |
| <input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><button type="button" id="help-button" title="help">?</button><a id="settings-menu" href="../../settings.html" title="settings"><img width="18" height="18" alt="Change settings" src="../../wheel.svg"></a></div></form></nav></div><section id="main-content" class="content"><div class="example-wrap"><pre class="line-numbers"><span id="1"> 1</span> |
| <span id="2"> 2</span> |
| <span id="3"> 3</span> |
| <span id="4"> 4</span> |
| <span id="5"> 5</span> |
| <span id="6"> 6</span> |
| <span id="7"> 7</span> |
| <span id="8"> 8</span> |
| <span id="9"> 9</span> |
| <span id="10"> 10</span> |
| <span id="11"> 11</span> |
| <span id="12"> 12</span> |
| <span id="13"> 13</span> |
| <span id="14"> 14</span> |
| <span id="15"> 15</span> |
| <span id="16"> 16</span> |
| <span id="17"> 17</span> |
| <span id="18"> 18</span> |
| <span id="19"> 19</span> |
| <span id="20"> 20</span> |
| <span id="21"> 21</span> |
| <span id="22"> 22</span> |
| <span id="23"> 23</span> |
| <span id="24"> 24</span> |
| <span id="25"> 25</span> |
| <span id="26"> 26</span> |
| <span id="27"> 27</span> |
| <span id="28"> 28</span> |
| <span id="29"> 29</span> |
| <span id="30"> 30</span> |
| <span id="31"> 31</span> |
| <span id="32"> 32</span> |
| <span id="33"> 33</span> |
| <span id="34"> 34</span> |
| <span id="35"> 35</span> |
| <span id="36"> 36</span> |
| <span id="37"> 37</span> |
| <span id="38"> 38</span> |
| <span id="39"> 39</span> |
| <span id="40"> 40</span> |
| <span id="41"> 41</span> |
| <span id="42"> 42</span> |
| <span id="43"> 43</span> |
| <span id="44"> 44</span> |
| <span id="45"> 45</span> |
| <span id="46"> 46</span> |
| <span id="47"> 47</span> |
| <span id="48"> 48</span> |
| <span id="49"> 49</span> |
| <span id="50"> 50</span> |
| <span id="51"> 51</span> |
| <span id="52"> 52</span> |
| <span id="53"> 53</span> |
| <span id="54"> 54</span> |
| <span id="55"> 55</span> |
| <span id="56"> 56</span> |
| <span id="57"> 57</span> |
| <span id="58"> 58</span> |
| <span id="59"> 59</span> |
| <span id="60"> 60</span> |
| <span id="61"> 61</span> |
| <span id="62"> 62</span> |
| <span id="63"> 63</span> |
| <span id="64"> 64</span> |
| <span id="65"> 65</span> |
| <span id="66"> 66</span> |
| <span id="67"> 67</span> |
| <span id="68"> 68</span> |
| <span id="69"> 69</span> |
| <span id="70"> 70</span> |
| <span id="71"> 71</span> |
| <span id="72"> 72</span> |
| <span id="73"> 73</span> |
| <span id="74"> 74</span> |
| <span id="75"> 75</span> |
| <span id="76"> 76</span> |
| <span id="77"> 77</span> |
| <span id="78"> 78</span> |
| <span id="79"> 79</span> |
| <span id="80"> 80</span> |
| <span id="81"> 81</span> |
| <span id="82"> 82</span> |
| <span id="83"> 83</span> |
| <span id="84"> 84</span> |
| <span id="85"> 85</span> |
| <span id="86"> 86</span> |
| <span id="87"> 87</span> |
| <span id="88"> 88</span> |
| <span id="89"> 89</span> |
| <span id="90"> 90</span> |
| <span id="91"> 91</span> |
| <span id="92"> 92</span> |
| <span id="93"> 93</span> |
| <span id="94"> 94</span> |
| <span id="95"> 95</span> |
| <span id="96"> 96</span> |
| <span id="97"> 97</span> |
| <span id="98"> 98</span> |
| <span id="99"> 99</span> |
| <span id="100">100</span> |
| <span id="101">101</span> |
| <span id="102">102</span> |
| <span id="103">103</span> |
| <span id="104">104</span> |
| <span id="105">105</span> |
| <span id="106">106</span> |
| <span id="107">107</span> |
| <span id="108">108</span> |
| <span id="109">109</span> |
| <span id="110">110</span> |
| <span id="111">111</span> |
| <span id="112">112</span> |
| <span id="113">113</span> |
| <span id="114">114</span> |
| <span id="115">115</span> |
| <span id="116">116</span> |
| <span id="117">117</span> |
| <span id="118">118</span> |
| <span id="119">119</span> |
| <span id="120">120</span> |
| <span id="121">121</span> |
| <span id="122">122</span> |
| <span id="123">123</span> |
| <span id="124">124</span> |
| <span id="125">125</span> |
| <span id="126">126</span> |
| <span id="127">127</span> |
| <span id="128">128</span> |
| <span id="129">129</span> |
| <span id="130">130</span> |
| <span id="131">131</span> |
| <span id="132">132</span> |
| <span id="133">133</span> |
| <span id="134">134</span> |
| <span id="135">135</span> |
| <span id="136">136</span> |
| <span id="137">137</span> |
| <span id="138">138</span> |
| <span id="139">139</span> |
| <span id="140">140</span> |
| <span id="141">141</span> |
| <span id="142">142</span> |
| <span id="143">143</span> |
| <span id="144">144</span> |
| <span id="145">145</span> |
| <span id="146">146</span> |
| <span id="147">147</span> |
| <span id="148">148</span> |
| <span id="149">149</span> |
| <span id="150">150</span> |
| <span id="151">151</span> |
| <span id="152">152</span> |
| <span id="153">153</span> |
| <span id="154">154</span> |
| <span id="155">155</span> |
| <span id="156">156</span> |
| <span id="157">157</span> |
| <span id="158">158</span> |
| <span id="159">159</span> |
| <span id="160">160</span> |
| <span id="161">161</span> |
| <span id="162">162</span> |
| <span id="163">163</span> |
| <span id="164">164</span> |
| <span id="165">165</span> |
| <span id="166">166</span> |
| <span id="167">167</span> |
| </pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project.</span> |
| <span class="comment">// Copyright 2016-2017 The Rust Project Developers.</span> |
| <span class="comment">//</span> |
| <span class="comment">// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or</span> |
| <span class="comment">// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license</span> |
| <span class="comment">// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your</span> |
| <span class="comment">// option. This file may not be copied, modified, or distributed</span> |
| <span class="comment">// except according to those terms.</span> |
| |
| <span class="doccomment">//! The Cauchy distribution.</span> |
| |
| <span class="kw">use</span> <span class="ident">num_traits</span>::{<span class="ident">Float</span>, <span class="ident">FloatConst</span>}; |
| <span class="kw">use</span> <span class="kw">crate</span>::{<span class="ident">Distribution</span>, <span class="ident">Standard</span>}; |
| <span class="kw">use</span> <span class="ident">rand::Rng</span>; |
| <span class="kw">use</span> <span class="ident">core::fmt</span>; |
| |
| <span class="doccomment">/// The Cauchy distribution `Cauchy(median, scale)`.</span> |
| <span class="doccomment">///</span> |
| <span class="doccomment">/// This distribution has a density function:</span> |
| <span class="doccomment">/// `f(x) = 1 / (pi * scale * (1 + ((x - median) / scale)^2))`</span> |
| <span class="doccomment">///</span> |
| <span class="doccomment">/// Note that at least for `f32`, results are not fully portable due to minor</span> |
| <span class="doccomment">/// differences in the target system's *tan* implementation, `tanf`.</span> |
| <span class="doccomment">///</span> |
| <span class="doccomment">/// # Example</span> |
| <span class="doccomment">///</span> |
| <span class="doccomment">/// ```</span> |
| <span class="doccomment">/// use rand_distr::{Cauchy, Distribution};</span> |
| <span class="doccomment">///</span> |
| <span class="doccomment">/// let cau = Cauchy::new(2.0, 5.0).unwrap();</span> |
| <span class="doccomment">/// let v = cau.sample(&mut rand::thread_rng());</span> |
| <span class="doccomment">/// println!("{} is from a Cauchy(2, 5) distribution", v);</span> |
| <span class="doccomment">/// ```</span> |
| <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>, <span class="ident">Copy</span>, <span class="ident">Debug</span>)]</span> |
| <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"serde1"</span>, <span class="ident">derive</span>(<span class="ident">serde::Serialize</span>, <span class="ident">serde::Deserialize</span>))]</span> |
| <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Cauchy</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> |
| <span class="kw">where</span> <span class="ident">F</span>: <span class="ident">Float</span> <span class="op">+</span> <span class="ident">FloatConst</span>, <span class="ident">Standard</span>: <span class="ident">Distribution</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> |
| { |
| <span class="ident">median</span>: <span class="ident">F</span>, |
| <span class="ident">scale</span>: <span class="ident">F</span>, |
| } |
| |
| <span class="doccomment">/// Error type returned from `Cauchy::new`.</span> |
| <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>, <span class="ident">Copy</span>, <span class="ident">Debug</span>, <span class="ident">PartialEq</span>, <span class="ident">Eq</span>)]</span> |
| <span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">Error</span> { |
| <span class="doccomment">/// `scale <= 0` or `nan`.</span> |
| <span class="ident">ScaleTooSmall</span>, |
| } |
| |
| <span class="kw">impl</span> <span class="ident">fmt::Display</span> <span class="kw">for</span> <span class="ident">Error</span> { |
| <span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&mut</span> <span class="ident">fmt::Formatter</span><span class="op"><</span><span class="lifetime">'_</span><span class="op">></span>) -> <span class="ident">fmt::Result</span> { |
| <span class="ident">f</span>.<span class="ident">write_str</span>(<span class="kw">match</span> <span class="self">self</span> { |
| <span class="ident">Error::ScaleTooSmall</span> => <span class="string">"scale is not positive in Cauchy distribution"</span>, |
| }) |
| } |
| } |
| |
| <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std"</span>)]</span> |
| <span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">doc_cfg</span>, <span class="ident">doc</span>(<span class="ident">cfg</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std"</span>)))]</span> |
| <span class="kw">impl</span> <span class="ident">std::error::Error</span> <span class="kw">for</span> <span class="ident">Error</span> {} |
| |
| <span class="kw">impl</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> <span class="ident">Cauchy</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> |
| <span class="kw">where</span> <span class="ident">F</span>: <span class="ident">Float</span> <span class="op">+</span> <span class="ident">FloatConst</span>, <span class="ident">Standard</span>: <span class="ident">Distribution</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> |
| { |
| <span class="doccomment">/// Construct a new `Cauchy` with the given shape parameters</span> |
| <span class="doccomment">/// `median` the peak location and `scale` the scale factor.</span> |
| <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">median</span>: <span class="ident">F</span>, <span class="ident">scale</span>: <span class="ident">F</span>) -> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">Cauchy</span><span class="op"><</span><span class="ident">F</span><span class="op">></span>, <span class="ident">Error</span><span class="op">></span> { |
| <span class="kw">if</span> <span class="op">!</span>(<span class="ident">scale</span> <span class="op">></span> <span class="ident">F::zero</span>()) { |
| <span class="kw">return</span> <span class="prelude-val">Err</span>(<span class="ident">Error::ScaleTooSmall</span>); |
| } |
| <span class="prelude-val">Ok</span>(<span class="ident">Cauchy</span> { <span class="ident">median</span>, <span class="ident">scale</span> }) |
| } |
| } |
| |
| <span class="kw">impl</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> <span class="ident">Distribution</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Cauchy</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> |
| <span class="kw">where</span> <span class="ident">F</span>: <span class="ident">Float</span> <span class="op">+</span> <span class="ident">FloatConst</span>, <span class="ident">Standard</span>: <span class="ident">Distribution</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> |
| { |
| <span class="kw">fn</span> <span class="ident">sample</span><span class="op"><</span><span class="ident">R</span>: <span class="ident">Rng</span> <span class="op">+</span> <span class="question-mark">?</span><span class="ident">Sized</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">rng</span>: <span class="kw-2">&mut</span> <span class="ident">R</span>) -> <span class="ident">F</span> { |
| <span class="comment">// sample from [0, 1)</span> |
| <span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="ident">Standard</span>.<span class="ident">sample</span>(<span class="ident">rng</span>); |
| <span class="comment">// get standard cauchy random number</span> |
| <span class="comment">// note that π/2 is not exactly representable, even if x=0.5 the result is finite</span> |
| <span class="kw">let</span> <span class="ident">comp_dev</span> <span class="op">=</span> (<span class="ident">F::PI</span>() <span class="op">*</span> <span class="ident">x</span>).<span class="ident">tan</span>(); |
| <span class="comment">// shift and scale according to parameters</span> |
| <span class="self">self</span>.<span class="ident">median</span> <span class="op">+</span> <span class="self">self</span>.<span class="ident">scale</span> <span class="op">*</span> <span class="ident">comp_dev</span> |
| } |
| } |
| |
| <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span> |
| <span class="kw">mod</span> <span class="ident">test</span> { |
| <span class="kw">use</span> <span class="kw">super</span>::<span class="kw-2">*</span>; |
| |
| <span class="kw">fn</span> <span class="ident">median</span>(<span class="ident">numbers</span>: <span class="kw-2">&mut</span> [<span class="ident">f64</span>]) -> <span class="ident">f64</span> { |
| <span class="ident">sort</span>(<span class="ident">numbers</span>); |
| <span class="kw">let</span> <span class="ident">mid</span> <span class="op">=</span> <span class="ident">numbers</span>.<span class="ident">len</span>() <span class="op">/</span> <span class="number">2</span>; |
| <span class="ident">numbers</span>[<span class="ident">mid</span>] |
| } |
| |
| <span class="kw">fn</span> <span class="ident">sort</span>(<span class="ident">numbers</span>: <span class="kw-2">&mut</span> [<span class="ident">f64</span>]) { |
| <span class="ident">numbers</span>.<span class="ident">sort_by</span>(<span class="op">|</span><span class="ident">a</span>, <span class="ident">b</span><span class="op">|</span> <span class="ident">a</span>.<span class="ident">partial_cmp</span>(<span class="ident">b</span>).<span class="ident">unwrap</span>()); |
| } |
| |
| <span class="attribute">#[<span class="ident">test</span>]</span> |
| <span class="kw">fn</span> <span class="ident">test_cauchy_averages</span>() { |
| <span class="comment">// NOTE: given that the variance and mean are undefined,</span> |
| <span class="comment">// this test does not have any rigorous statistical meaning.</span> |
| <span class="kw">let</span> <span class="ident">cauchy</span> <span class="op">=</span> <span class="ident">Cauchy::new</span>(<span class="number">10.0</span>, <span class="number">5.0</span>).<span class="ident">unwrap</span>(); |
| <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">rng</span> <span class="op">=</span> <span class="ident"><span class="kw">crate</span>::test::rng</span>(<span class="number">123</span>); |
| <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">numbers</span>: [<span class="ident">f64</span>; <span class="number">1000</span>] <span class="op">=</span> [<span class="number">0.0</span>; <span class="number">1000</span>]; |
| <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">sum</span> <span class="op">=</span> <span class="number">0.0</span>; |
| <span class="kw">for</span> <span class="ident">number</span> <span class="kw">in</span> <span class="kw-2">&mut</span> <span class="ident">numbers</span>[..] { |
| <span class="kw-2">*</span><span class="ident">number</span> <span class="op">=</span> <span class="ident">cauchy</span>.<span class="ident">sample</span>(<span class="kw-2">&mut</span> <span class="ident">rng</span>); |
| <span class="ident">sum</span> <span class="op">+</span><span class="op">=</span> <span class="kw-2">*</span><span class="ident">number</span>; |
| } |
| <span class="kw">let</span> <span class="ident">median</span> <span class="op">=</span> <span class="ident">median</span>(<span class="kw-2">&mut</span> <span class="ident">numbers</span>); |
| <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std"</span>)]</span> |
| <span class="macro">std::println!</span>(<span class="string">"Cauchy median: {}"</span>, <span class="ident">median</span>); |
| <span class="macro">assert!</span>((<span class="ident">median</span> <span class="op">-</span> <span class="number">10.0</span>).<span class="ident">abs</span>() <span class="op"><</span> <span class="number">0.4</span>); <span class="comment">// not 100% certain, but probable enough</span> |
| <span class="kw">let</span> <span class="ident">mean</span> <span class="op">=</span> <span class="ident">sum</span> <span class="op">/</span> <span class="number">1000.0</span>; |
| <span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std"</span>)]</span> |
| <span class="macro">std::println!</span>(<span class="string">"Cauchy mean: {}"</span>, <span class="ident">mean</span>); |
| <span class="comment">// for a Cauchy distribution the mean should not converge</span> |
| <span class="macro">assert!</span>((<span class="ident">mean</span> <span class="op">-</span> <span class="number">10.0</span>).<span class="ident">abs</span>() <span class="op">></span> <span class="number">0.4</span>); <span class="comment">// not 100% certain, but probable enough</span> |
| } |
| |
| <span class="attribute">#[<span class="ident">test</span>]</span> |
| <span class="attribute">#[<span class="ident">should_panic</span>]</span> |
| <span class="kw">fn</span> <span class="ident">test_cauchy_invalid_scale_zero</span>() { |
| <span class="ident">Cauchy::new</span>(<span class="number">0.0</span>, <span class="number">0.0</span>).<span class="ident">unwrap</span>(); |
| } |
| |
| <span class="attribute">#[<span class="ident">test</span>]</span> |
| <span class="attribute">#[<span class="ident">should_panic</span>]</span> |
| <span class="kw">fn</span> <span class="ident">test_cauchy_invalid_scale_neg</span>() { |
| <span class="ident">Cauchy::new</span>(<span class="number">0.0</span>, <span class="op">-</span><span class="number">10.0</span>).<span class="ident">unwrap</span>(); |
| } |
| |
| <span class="attribute">#[<span class="ident">test</span>]</span> |
| <span class="kw">fn</span> <span class="ident">value_stability</span>() { |
| <span class="kw">fn</span> <span class="ident">gen_samples</span><span class="op"><</span><span class="ident">F</span>: <span class="ident">Float</span> <span class="op">+</span> <span class="ident">FloatConst</span> <span class="op">+</span> <span class="ident">core::fmt::Debug</span><span class="op">></span>(<span class="ident">m</span>: <span class="ident">F</span>, <span class="ident">s</span>: <span class="ident">F</span>, <span class="ident">buf</span>: <span class="kw-2">&mut</span> [<span class="ident">F</span>]) |
| <span class="kw">where</span> <span class="ident">Standard</span>: <span class="ident">Distribution</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> { |
| <span class="kw">let</span> <span class="ident">distr</span> <span class="op">=</span> <span class="ident">Cauchy::new</span>(<span class="ident">m</span>, <span class="ident">s</span>).<span class="ident">unwrap</span>(); |
| <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">rng</span> <span class="op">=</span> <span class="ident"><span class="kw">crate</span>::test::rng</span>(<span class="number">353</span>); |
| <span class="kw">for</span> <span class="ident">x</span> <span class="kw">in</span> <span class="ident">buf</span> { |
| <span class="kw-2">*</span><span class="ident">x</span> <span class="op">=</span> <span class="ident">rng</span>.<span class="ident">sample</span>(<span class="kw-2">&</span><span class="ident">distr</span>); |
| } |
| } |
| |
| <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">buf</span> <span class="op">=</span> [<span class="number">0.0</span>; <span class="number">4</span>]; |
| <span class="ident">gen_samples</span>(<span class="number">100f64</span>, <span class="number">10.0</span>, <span class="kw-2">&mut</span> <span class="ident">buf</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">&</span><span class="ident">buf</span>, <span class="kw-2">&</span>[ |
| <span class="number">77.93369152808678</span>, |
| <span class="number">90.1606912098641</span>, |
| <span class="number">125.31516221323625</span>, |
| <span class="number">86.10217834773925</span> |
| ]); |
| |
| <span class="comment">// Unfortunately this test is not fully portable due to reliance on the</span> |
| <span class="comment">// system's implementation of tanf (see doc on Cauchy struct).</span> |
| <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">buf</span> <span class="op">=</span> [<span class="number">0.0</span>; <span class="number">4</span>]; |
| <span class="ident">gen_samples</span>(<span class="number">10f32</span>, <span class="number">7.0</span>, <span class="kw-2">&mut</span> <span class="ident">buf</span>); |
| <span class="kw">let</span> <span class="ident">expected</span> <span class="op">=</span> [<span class="number">15.023088</span>, <span class="op">-</span><span class="number">5.446413</span>, <span class="number">3.7092876</span>, <span class="number">3.112482</span>]; |
| <span class="kw">for</span> (<span class="ident">a</span>, <span class="ident">b</span>) <span class="kw">in</span> <span class="ident">buf</span>.<span class="ident">iter</span>().<span class="ident">zip</span>(<span class="ident">expected</span>.<span class="ident">iter</span>()) { |
| <span class="macro">assert_almost_eq!</span>(<span class="kw-2">*</span><span class="ident">a</span>, <span class="kw-2">*</span><span class="ident">b</span>, <span class="number">1e-5</span>); |
| } |
| } |
| } |
| </code></pre></div> |
| </section><section id="search" class="content hidden"></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="rand_distr" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.60.0-nightly (1bd4fdc94 2022-01-12)" ></div> |
| </body></html> |
