175 lines
16 KiB
HTML
175 lines
16 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
|
|
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<title>std::tanh(std::valarray)</title>
|
|
<link rel="stylesheet" href="ext.css" />
|
|
<link rel="stylesheet" href="site_modules.css" />
|
|
</head>
|
|
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_numeric_valarray_tanh skin-cppreference2 action-view cpp-navbar">
|
|
<div id="cpp-content-base">
|
|
<div id="content"><a id="top"></a>
|
|
<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>tanh<span style="font-size:0.7em; line-height:130%">(std::valarray)</span></h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-numeric.html">numeric</a>‎ | <a href="cpp-numeric-valarray.html">valarray</a></span></div>
|
|
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dsc-header">
|
|
<td>
|
|
<div>定义于头文件 <code><a href="cpp-header-valarray.html"><valarray></a></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl">
|
|
<td class="t-dcl-nopad">
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> T <span class="sy1">></span><br />
|
|
valarray<span class="sy1"><</span>T<span class="sy1">></span> tanh<span class="br0">(</span> <span class="kw4">const</span> valarray<span class="sy1"><</span>T<span class="sy1">></span><span class="sy3">&</span> va <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td class="t-dcl-nopad"></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p>对 <code>va</code> 中每个元素计算元素值的双曲正切。</p>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
|
|
<table class="t-par-begin">
|
|
<tr class="t-par">
|
|
<td>va</td>
|
|
<td>-</td>
|
|
<td>要应用操作到的值数组</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p>含有 <code>va</code> 中值的双曲正切的值数组。</p>
|
|
<h3><span class="mw-headline" id=".E6.B3.A8.E8.A7.A3">注解</span></h3>
|
|
<p>用无限定函数 (<span class="t-c"><span class="mw-geshi cpp source-cpp">tanh</span></span>) 进行计算。若该函数不可用，则因参数依赖查找使用 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-numeric-math-tanh.html"><span class="kw1342">std::<span class="me2">tanh</span></span></a></span></span> 。</p>
|
|
<p>函数能实现为拥有不同于 <span class="t-lc"><a href="cpp-numeric-valarray.html">std::valarray</a></span> 的返回类型。此情况下，替换类型拥有下列属性：</p>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>提供 <span class="t-lc"><a href="cpp-numeric-valarray.html">std::valarray</a></span> 的所有 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">const</span></span></span> 成员函数。</li>
|
|
<li>能从替换类型构造 <span class="t-lc"><a href="cpp-numeric-valarray.html">std::valarray</a></span> 、 <span class="t-lc"><a href="cpp-numeric-valarray-slice_array.html">std::slice_array</a></span> 、 <span class="t-lc"><a href="cpp-numeric-valarray-gslice_array.html">std::gslice_array</a></span> 、 <span class="t-lc"><a href="cpp-numeric-valarray-mask_array.html">std::mask_array</a></span> 和 <span class="t-lc"><a href="cpp-numeric-valarray-indirect_array.html">std::indirect_array</a></span> 。</li>
|
|
<li>所有接受一个 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy3">&</span></span></span> 类型参数的函数<span class="t-rev-inl t-since-cxx11"><span>，除了 <a href="cpp-numeric-valarray-begin2.html"><tt>begin()</tt></a> 和 <a href="cpp-numeric-valarray-end2.html"><tt>end()</tt></a></span> <span><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></span></span>也应该接受替换类型。</li>
|
|
<li>所有接受二个 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy3">&</span></span></span> 类型参数的函数都应该接受 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy3">&</span></span></span> 和替换类型的每种组合。</li>
|
|
<li>返回类型添加不多于二层嵌套在最深层嵌套的参数类型上的模板。</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<h3><span class="mw-headline" id=".E5.8F.AF.E8.83.BD.E7.9A.84.E5.AE.9E.E7.8E.B0">可能的实现</span></h3>
|
|
<table class="eq-fun-cpp-table">
|
|
<tr>
|
|
<td>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="cpp source-cpp">
|
|
<pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T<span class="sy1">></span>
|
|
valarray<span class="sy1"><</span>T<span class="sy1">></span> tanh<span class="br0">(</span><span class="kw4">const</span> valarray<span class="sy1"><</span>T<span class="sy1">></span><span class="sy3">&</span> va<span class="br0">)</span>
|
|
<span class="br0">{</span>
|
|
valarray<span class="sy1"><</span>T<span class="sy1">></span> other <span class="sy1">=</span> va<span class="sy4">;</span>
|
|
<span class="kw1">for</span> <span class="br0">(</span>T <span class="sy3">&</span>i <span class="sy4">:</span> other<span class="br0">)</span> <span class="br0">{</span>
|
|
i <span class="sy1">=</span> tanh<span class="br0">(</span>i<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span>
|
|
<span class="kw1">return</span> other<span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
|
<div class="t-example">
|
|
<div class="t-example-live-link"></div>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="cpp source-cpp">
|
|
<pre class="de1"><span class="co2">#include <cmath></span>
|
|
<span class="co2">#include <iostream></span>
|
|
<span class="co2">#include <valarray></span>
|
|
|
|
<span class="kw4">auto</span> show <span class="sy1">=</span> <span class="br0">[</span><span class="br0">]</span><span class="br0">(</span><span class="kw4">char</span> <span class="kw4">const</span><span class="sy2">*</span> title, <span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1"><</span><span class="kw4">double</span><span class="sy1">></span><span class="sy3">&</span> va<span class="br0">)</span> <span class="br0">{</span>
|
|
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> title <span class="sy1"><<</span> <span class="st0">" :"</span><span class="sy4">;</span>
|
|
<span class="kw1">for</span><span class="br0">(</span><span class="kw4">auto</span> x <span class="sy4">:</span> va<span class="br0">)</span>
|
|
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">" "</span> <span class="sy1"><<</span> <a href="cpp-io-manip-fixed.html"><span class="kw1784">std::<span class="me2">fixed</span></span></a> <span class="sy1"><<</span> x<span class="sy4">;</span>
|
|
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
|
|
<span class="br0">}</span><span class="sy4">;</span>
|
|
|
|
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
|
|
<span class="br0">{</span>
|
|
<span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1"><</span><span class="kw4">double</span><span class="sy1">></span> x <span class="sy1">=</span> <span class="br0">{</span><span class="nu18">.0</span>, <span class="nu18">.1</span>, <span class="nu18">.2</span>, <span class="nu18">.3</span><span class="br0">}</span><span class="sy4">;</span>
|
|
<span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1"><</span><span class="kw4">double</span><span class="sy1">></span> sinh <span class="sy1">=</span> <a href="cpp-numeric-math-sinh.html"><span class="kw1340">std::<span class="me2">sinh</span></span></a><span class="br0">(</span>x<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1"><</span><span class="kw4">double</span><span class="sy1">></span> cosh <span class="sy1">=</span> <a href="cpp-numeric-math-cosh.html"><span class="kw1341">std::<span class="me2">cosh</span></span></a><span class="br0">(</span>x<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1"><</span><span class="kw4">double</span><span class="sy1">></span> tanh <span class="sy1">=</span> <a href="cpp-numeric-math-tanh.html"><span class="kw1342">std::<span class="me2">tanh</span></span></a><span class="br0">(</span>x<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1"><</span><span class="kw4">double</span><span class="sy1">></span> tanh_by_def <span class="sy1">=</span> sinh <span class="sy2">/</span> cosh<span class="sy4">;</span>
|
|
<span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1"><</span><span class="kw4">double</span><span class="sy1">></span> tanh_2x <span class="sy1">=</span> <a href="cpp-numeric-math-tanh.html"><span class="kw1342">std::<span class="me2">tanh</span></span></a><span class="br0">(</span><span class="nu16">2.0</span> <span class="sy2">*</span> x<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1"><</span><span class="kw4">double</span><span class="sy1">></span> tanh_2x_by_def <span class="sy1">=</span>
|
|
<span class="br0">(</span><span class="nu16">2.0</span> <span class="sy2">*</span> tanh<span class="br0">)</span> <span class="sy2">/</span> <span class="br0">(</span><span class="nu16">1.0</span> <span class="sy2">+</span> <a href="cpp-numeric-math-pow.html"><span class="kw1332">std::<span class="me2">pow</span></span></a><span class="br0">(</span>tanh, <span class="nu16">2.0</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
|
|
|
|
show<span class="br0">(</span><span class="st0">"x "</span>, x<span class="br0">)</span><span class="sy4">;</span>
|
|
show<span class="br0">(</span><span class="st0">"tanh(x) "</span>, tanh<span class="br0">)</span><span class="sy4">;</span>
|
|
show<span class="br0">(</span><span class="st0">"tanh(x) (def) "</span>, tanh_by_def<span class="br0">)</span><span class="sy4">;</span>
|
|
show<span class="br0">(</span><span class="st0">"tanh(2*x) "</span>, tanh_2x<span class="br0">)</span><span class="sy4">;</span>
|
|
show<span class="br0">(</span><span class="st0">"tanh(2*x) (def)"</span>, tanh_2x_by_def<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
<p>输出：</p>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="text source-text">
|
|
<pre class="de1">x : 0.000000 0.100000 0.200000 0.300000
|
|
tanh(x) : 0.000000 0.099668 0.197375 0.291313
|
|
tanh(x) (def) : 0.000000 0.099668 0.197375 0.291313
|
|
tanh(2*x) : 0.000000 0.197375 0.379949 0.537050
|
|
tanh(2*x) (def) : 0.000000 0.197375 0.379949 0.537050</pre></div>
|
|
</div>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-numeric-valarray-sinh.html"><span class="t-lines"><span>sinh<span class="t-dsc-small">(std::valarray)</span></span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>在 valarray 的每个元素上调用 <span class="t-lc"><a href="cpp-numeric-math-sinh.html">std::sinh</a></span> 函数<br />
|
|
<span class="t-mark">(函数模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-numeric-valarray-cosh.html"><span class="t-lines"><span>cosh<span class="t-dsc-small">(std::valarray)</span></span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>在 valarray 的每个元素上调用 <span class="t-lc"><a href="cpp-numeric-math-cosh.html">std::cosh</a></span> 函数<br />
|
|
<span class="t-mark">(函数模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-numeric-math-tanh.html"><span class="t-lines"><span>tanh</span><span>tanhf</span><span>tanhl</span></span></a></div>
|
|
<div><span class="t-lines"><span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>计算双曲正切（ <span class="mjax" style="display:none">\({\small\tanh{x} }\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;">tanh(x)</span> ）<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-numeric-complex-tanh.html"><span class="t-lines"><span>tanh<span class="t-dsc-small">(std::complex)</span></span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>计算复数的双曲正切（ <span class="mjax" style="display:none">\({\small\tanh{z} }\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;">tanh(z)</span> ）<br />
|
|
<span class="t-mark">(函数模板)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|