1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Class template discrete_distribution</title> 5<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../index.html" title="Chapter 1. Boost.Compute"> 8<link rel="up" href="../../boost_compute/reference.html#header.boost.compute.random.discrete_distribution_hpp" title="Header <boost/compute/random/discrete_distribution.hpp>"> 9<link rel="prev" href="bernoulli_distribution.html" title="Class template bernoulli_distribution"> 10<link rel="next" href="linear_congruential_engine.html" title="Class template linear_congruential_engine"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="bernoulli_distribution.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../boost_compute/reference.html#header.boost.compute.random.discrete_distribution_hpp"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="linear_congruential_engine.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="refentry"> 26<a name="boost.compute.discrete_distribution"></a><div class="titlepage"></div> 27<div class="refnamediv"> 28<h2><span class="refentrytitle">Class template discrete_distribution</span></h2> 29<p>boost::compute::discrete_distribution — Produces random integers on the interval [0, n), where probability of each integer is given by the weight of the ith integer divided by the sum of all weights. </p> 30</div> 31<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 32<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../boost_compute/reference.html#header.boost.compute.random.discrete_distribution_hpp" title="Header <boost/compute/random/discrete_distribution.hpp>">boost/compute/random/discrete_distribution.hpp</a>> 33 34</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> IntType <span class="special">=</span> <span class="identifier">uint_</span><span class="special">></span> 35<span class="keyword">class</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">{</span> 36<span class="keyword">public</span><span class="special">:</span> 37 <span class="comment">// types</span> 38 <span class="keyword">typedef</span> <span class="identifier">IntType</span> <a name="boost.compute.discrete_distribution.result_type"></a><span class="identifier">result_type</span><span class="special">;</span> 39 40 <span class="comment">// <a class="link" href="discrete_distribution.html#boost.compute.discrete_distributionconstruct-copy-destruct">construct/copy/destruct</a></span> 41 <a class="link" href="discrete_distribution.html#idm45549384440784-bb"><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 42 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> InputIterator<span class="special">></span> 43 <a class="link" href="discrete_distribution.html#idm45549384439984-bb"><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="identifier">InputIterator</span><span class="special">,</span> <span class="identifier">InputIterator</span><span class="special">)</span><span class="special">;</span> 44 <a class="link" href="discrete_distribution.html#idm45549384436112-bb"><span class="special">~</span><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 45 46 <span class="comment">// <a class="link" href="discrete_distribution.html#idm45549384452208-bb">public member functions</a></span> 47 <span class="special">::</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="keyword">double</span> <span class="special">></span> <a class="link" href="discrete_distribution.html#idm45549384451648-bb"><span class="identifier">probabilities</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 48 <span class="identifier">result_type</span> <span class="identifier">min</span> <a class="link" href="discrete_distribution.html#idm45549384450224-bb"><span class="identifier">BOOST_PREVENT_MACRO_SUBSTITUTION</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 49 <span class="identifier">result_type</span> <span class="identifier">max</span> <a class="link" href="discrete_distribution.html#idm45549384448768-bb"><span class="identifier">BOOST_PREVENT_MACRO_SUBSTITUTION</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 50 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> OutputIterator<span class="special">,</span> <span class="keyword">typename</span> Generator<span class="special">></span> 51 <span class="keyword">void</span> <a class="link" href="discrete_distribution.html#idm45549384447312-bb"><span class="identifier">generate</span></a><span class="special">(</span><span class="identifier">OutputIterator</span><span class="special">,</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="identifier">Generator</span> <span class="special">&</span><span class="special">,</span> 52 <span class="identifier">command_queue</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 53 54 <span class="comment">// <a class="link" href="discrete_distribution.html#idm45549384434800-bb">private member functions</a></span> 55 <a class="link" href="discrete_distribution.html#idm45549384434224-bb"><span class="identifier">BOOST_STATIC_ASSERT_MSG</span></a><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_integral</span><span class="special"><</span> <span class="identifier">IntType</span> <span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">,</span> 56 <span class="string">"Template argument must be integral"</span><span class="special">)</span><span class="special">;</span> 57<span class="special">}</span><span class="special">;</span></pre></div> 58<div class="refsect1"> 59<a name="idm45849505296352"></a><h2>Description</h2> 60<p>The following example shows how to setup a discrete distribution to produce 0 and 1 with equal probability</p> 61<pre class="programlisting"></pre> 62<div class="refsect2"> 63<a name="idm45849505295024"></a><h3> 64<a name="boost.compute.discrete_distributionconstruct-copy-destruct"></a><code class="computeroutput">discrete_distribution</code> 65 public 66 construct/copy/destruct</h3> 67<div class="orderedlist"><ol class="orderedlist" type="1"> 68<li class="listitem"> 69<pre class="literallayout"><a name="idm45549384440784-bb"></a><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 70<p>Creates a new discrete distribution with a single weight p = { 1 }. This distribution produces only zeroes. </p> 71</li> 72<li class="listitem"> 73<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> InputIterator<span class="special">></span> 74 <a name="idm45549384439984-bb"></a><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="identifier">InputIterator</span> first<span class="special">,</span> <span class="identifier">InputIterator</span> last<span class="special">)</span><span class="special">;</span></pre> 75<p>Creates a new discrete distribution with weights given by the range [<code class="computeroutput">first</code>, <code class="computeroutput">last</code>). </p> 76</li> 77<li class="listitem"> 78<pre class="literallayout"><a name="idm45549384436112-bb"></a><span class="special">~</span><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Destroys the <code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code> object. </li> 79</ol></div> 80</div> 81<div class="refsect2"> 82<a name="idm45849505273280"></a><h3> 83<a name="idm45549384452208-bb"></a><code class="computeroutput">discrete_distribution</code> public member functions</h3> 84<div class="orderedlist"><ol class="orderedlist" type="1"> 85<li class="listitem"> 86<pre class="literallayout"><span class="special">::</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="keyword">double</span> <span class="special">></span> <a name="idm45549384451648-bb"></a><span class="identifier">probabilities</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>Returns the probabilities. </li> 87<li class="listitem"> 88<pre class="literallayout"><span class="identifier">result_type</span> <span class="identifier">min</span> <a name="idm45549384450224-bb"></a><span class="identifier">BOOST_PREVENT_MACRO_SUBSTITUTION</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>Returns the minimum potentially generated value. </li> 89<li class="listitem"> 90<pre class="literallayout"><span class="identifier">result_type</span> <span class="identifier">max</span> <a name="idm45549384448768-bb"></a><span class="identifier">BOOST_PREVENT_MACRO_SUBSTITUTION</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>Returns the maximum potentially generated value. </li> 91<li class="listitem"> 92<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> OutputIterator<span class="special">,</span> <span class="keyword">typename</span> Generator<span class="special">></span> 93 <span class="keyword">void</span> <a name="idm45549384447312-bb"></a><span class="identifier">generate</span><span class="special">(</span><span class="identifier">OutputIterator</span> first<span class="special">,</span> <span class="identifier">OutputIterator</span> last<span class="special">,</span> 94 <span class="identifier">Generator</span> <span class="special">&</span> generator<span class="special">,</span> <span class="identifier">command_queue</span> <span class="special">&</span> queue<span class="special">)</span><span class="special">;</span></pre> 95<p>Generates uniformly distributed integers and stores them to the range [<code class="computeroutput">first</code>, <code class="computeroutput">last</code>). </p> 96</li> 97</ol></div> 98</div> 99<div class="refsect2"> 100<a name="idm45849505234704"></a><h3> 101<a name="idm45549384434800-bb"></a><code class="computeroutput">discrete_distribution</code> private member functions</h3> 102<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><pre class="literallayout"> <a name="idm45549384434224-bb"></a><span class="identifier">BOOST_STATIC_ASSERT_MSG</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_integral</span><span class="special"><</span> <span class="identifier">IntType</span> <span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">,</span> 103 <span class="string">"Template argument must be integral"</span><span class="special">)</span><span class="special">;</span></pre></li></ol></div> 104</div> 105</div> 106</div> 107<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 108<td align="left"></td> 109<td align="right"><div class="copyright-footer">Copyright © 2013, 2014 Kyle Lutz<p> 110 Distributed under the Boost Software License, Version 1.0. (See accompanying 111 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 112 </p> 113</div></td> 114</tr></table> 115<hr> 116<div class="spirit-nav"> 117<a accesskey="p" href="bernoulli_distribution.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../boost_compute/reference.html#header.boost.compute.random.discrete_distribution_hpp"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="linear_congruential_engine.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 118</div> 119</body> 120</html> 121
