<!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 to the Rust file `/home/mrh/.cargo/registry/src/github.com-1ecc6299db9ec823/libm-0.1.4/src/math/sin.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>sin.rs.html -- source</title><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="../../../dark.css"><link rel="stylesheet" type="text/css" href="../../../light.css" id="themeStyle"><script src="../../../storage.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="shortcut icon" href="../../../favicon.ico"><style type="text/css">#crate-search{background-image:url("../../../down-arrow.svg");}</style></head><body class="rustdoc source"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div><a href='../../../libm/index.html'><div class='logo-container'><img src='../../../rust-logo.png' alt='logo'></div></a></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../../../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../../../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><a id="settings-menu" href="../../../settings.html"><img src="../../../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><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>
</pre><div class="example-wrap"><pre class="rust ">
<span class="comment">// origin: FreeBSD /usr/src/lib/msun/src/s_sin.c */</span>
<span class="comment">//</span>
<span class="comment">// ====================================================</span>
<span class="comment">// Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.</span>
<span class="comment">//</span>
<span class="comment">// Developed at SunPro, a Sun Microsystems, Inc. business.</span>
<span class="comment">// Permission to use, copy, modify, and distribute this</span>
<span class="comment">// software is freely granted, provided that this notice</span>
<span class="comment">// is preserved.</span>
<span class="comment">// ====================================================</span>
<span class="kw">use</span> <span class="kw">super</span>::{<span class="ident">k_cos</span>, <span class="ident">k_sin</span>, <span class="ident">rem_pio2</span>};
<span class="comment">// sin(x)</span>
<span class="comment">// Return sine function of x.</span>
<span class="comment">//</span>
<span class="comment">// kernel function:</span>
<span class="comment">// k_sin ... sine function on [-pi/4,pi/4]</span>
<span class="comment">// k_cos ... cose function on [-pi/4,pi/4]</span>
<span class="comment">// rem_pio2 ... argument reduction routine</span>
<span class="comment">//</span>
<span class="comment">// Method.</span>
<span class="comment">// Let S,C and T denote the sin, cos and tan respectively on</span>
<span class="comment">// [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2</span>
<span class="comment">// in [-pi/4 , +pi/4], and let n = k mod 4.</span>
<span class="comment">// We have</span>
<span class="comment">//</span>
<span class="comment">// n sin(x) cos(x) tan(x)</span>
<span class="comment">// ----------------------------------------------------------</span>
<span class="comment">// 0 S C T</span>
<span class="comment">// 1 C -S -1/T</span>
<span class="comment">// 2 -S -C T</span>
<span class="comment">// 3 -C S -1/T</span>
<span class="comment">// ----------------------------------------------------------</span>
<span class="comment">//</span>
<span class="comment">// Special cases:</span>
<span class="comment">// Let trig be any of sin, cos, or tan.</span>
<span class="comment">// trig(+-INF) is NaN, with signals;</span>
<span class="comment">// trig(NaN) is that NaN;</span>
<span class="comment">//</span>
<span class="comment">// Accuracy:</span>
<span class="comment">// TRIG(x) returns trig(x) nearly rounded</span>
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">all</span>(<span class="ident">test</span>, <span class="ident">assert_no_panic</span>), <span class="ident">no_panic</span>::<span class="ident">no_panic</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">sin</span>(<span class="ident">x</span>: <span class="ident">f64</span>) <span class="op">-</span><span class="op">></span> <span class="ident">f64</span> {
<span class="kw">let</span> <span class="ident">x1p120</span> <span class="op">=</span> <span class="ident">f64</span>::<span class="ident">from_bits</span>(<span class="number">0x4770000000000000</span>); <span class="comment">// 0x1p120f === 2 ^ 120</span>
<span class="comment">/* High word of x. */</span>
<span class="kw">let</span> <span class="ident">ix</span> <span class="op">=</span> (<span class="ident">f64</span>::<span class="ident">to_bits</span>(<span class="ident">x</span>) <span class="op">></span><span class="op">></span> <span class="number">32</span>) <span class="kw">as</span> <span class="ident">u32</span> <span class="op">&</span> <span class="number">0x7fffffff</span>;
<span class="comment">/* |x| ~< pi/4 */</span>
<span class="kw">if</span> <span class="ident">ix</span> <span class="op"><</span><span class="op">=</span> <span class="number">0x3fe921fb</span> {
<span class="kw">if</span> <span class="ident">ix</span> <span class="op"><</span> <span class="number">0x3e500000</span> {
<span class="comment">/* |x| < 2**-26 */</span>
<span class="comment">/* raise inexact if x != 0 and underflow if subnormal*/</span>
<span class="kw">if</span> <span class="ident">ix</span> <span class="op"><</span> <span class="number">0x00100000</span> {
<span class="macro">force_eval</span><span class="macro">!</span>(<span class="ident">x</span> <span class="op">/</span> <span class="ident">x1p120</span>);
} <span class="kw">else</span> {
<span class="macro">force_eval</span><span class="macro">!</span>(<span class="ident">x</span> <span class="op">+</span> <span class="ident">x1p120</span>);
}
<span class="kw">return</span> <span class="ident">x</span>;
}
<span class="kw">return</span> <span class="ident">k_sin</span>(<span class="ident">x</span>, <span class="number">0.0</span>, <span class="number">0</span>);
}
<span class="comment">/* sin(Inf or NaN) is NaN */</span>
<span class="kw">if</span> <span class="ident">ix</span> <span class="op">></span><span class="op">=</span> <span class="number">0x7ff00000</span> {
<span class="kw">return</span> <span class="ident">x</span> <span class="op">-</span> <span class="ident">x</span>;
}
<span class="comment">/* argument reduction needed */</span>
<span class="kw">let</span> (<span class="ident">n</span>, <span class="ident">y0</span>, <span class="ident">y1</span>) <span class="op">=</span> <span class="ident">rem_pio2</span>(<span class="ident">x</span>);
<span class="kw">match</span> <span class="ident">n</span> <span class="op">&</span> <span class="number">3</span> {
<span class="number">0</span> <span class="op">=</span><span class="op">></span> <span class="ident">k_sin</span>(<span class="ident">y0</span>, <span class="ident">y1</span>, <span class="number">1</span>),
<span class="number">1</span> <span class="op">=</span><span class="op">></span> <span class="ident">k_cos</span>(<span class="ident">y0</span>, <span class="ident">y1</span>),
<span class="number">2</span> <span class="op">=</span><span class="op">></span> <span class="op">-</span><span class="ident">k_sin</span>(<span class="ident">y0</span>, <span class="ident">y1</span>, <span class="number">1</span>),
<span class="kw">_</span> <span class="op">=</span><span class="op">></span> <span class="op">-</span><span class="ident">k_cos</span>(<span class="ident">y0</span>, <span class="ident">y1</span>),
}
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">test_near_pi</span>() {
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="ident">f64</span>::<span class="ident">from_bits</span>(<span class="number">0x400921fb000FD5DD</span>); <span class="comment">// 3.141592026217707</span>
<span class="kw">let</span> <span class="ident">sx</span> <span class="op">=</span> <span class="ident">f64</span>::<span class="ident">from_bits</span>(<span class="number">0x3ea50d15ced1a4a2</span>); <span class="comment">// 6.273720864039205e-7</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">sin</span>(<span class="ident">x</span>), <span class="ident">sx</span>);
}
</pre></div>
</section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd>↑</kbd></dt><dd>Move up in search results</dd><dt><kbd>↓</kbd></dt><dd>Move down in search results</dd><dt><kbd>↹</kbd></dt><dd>Switch tab</dd><dt><kbd>⏎</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g., <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g., <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g., <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../../../";window.currentCrate = "libm";</script><script src="../../../aliases.js"></script><script src="../../../main.js"></script><script src="../../../source-script.js"></script><script src="../../../source-files.js"></script><script defer src="../../../search-index.js"></script></body></html>