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<title>Class template discrete_distribution</title>
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<div class="refentry">
<a name="boost.random.discrete_distribution"></a><div class="titlepage"></div>
<div class="refnamediv">
<h2><span class="refentrytitle">Class template discrete_distribution</span></h2>
<p>boost::random::discrete_distribution</p>
</div>
<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2>
<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_random/reference.html#header.boost.random.discrete_distribution_hpp" title="Header <boost/random/discrete_distribution.hpp>">boost/random/discrete_distribution.hpp</a>>
</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> IntType <span class="special">=</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">typename</span> WeightType <span class="special">=</span> <span class="keyword">double</span><span class="special">></span>
<span class="keyword">class</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
<span class="comment">// types</span>
<span class="keyword">typedef</span> <span class="identifier">WeightType</span> <a name="boost.random.discrete_distribution.input_type"></a><span class="identifier">input_type</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">IntType</span> <a name="boost.random.discrete_distribution.result_type"></a><span class="identifier">result_type</span><span class="special">;</span>
<span class="comment">// member classes/structs/unions</span>
<span class="keyword">class</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
<span class="comment">// types</span>
<span class="keyword">typedef</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <a class="link" href="discrete_distribution/param_type.html#boost.random.discrete_distribution.param_type.distribution_type"><span class="identifier">distribution_type</span></a><span class="special">;</span>
<span class="comment">// <a class="link" href="discrete_distribution/param_type.html#boost.random.discrete_distribution.param_typeconstruct-copy-destruct">construct/copy/destruct</a></span>
<a class="link" href="discrete_distribution/param_type.html#idp59380776-bb"><span class="identifier">param_type</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Iter<span class="special">></span> <a class="link" href="discrete_distribution/param_type.html#idp59383976-bb"><span class="identifier">param_type</span></a><span class="special">(</span><span class="identifier">Iter</span><span class="special">,</span> <span class="identifier">Iter</span><span class="special">)</span><span class="special">;</span>
<a class="link" href="discrete_distribution/param_type.html#idp59385912-bb"><span class="identifier">param_type</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">initializer_list</span><span class="special"><</span> <span class="identifier">WeightType</span> <span class="special">></span> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Range<span class="special">></span> <span class="keyword">explicit</span> <a class="link" href="discrete_distribution/param_type.html#idp59423384-bb"><span class="identifier">param_type</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">Range</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Func<span class="special">></span> <a class="link" href="discrete_distribution/param_type.html#idp59424696-bb"><span class="identifier">param_type</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="keyword">double</span><span class="special">,</span> <span class="keyword">double</span><span class="special">,</span> <span class="identifier">Func</span><span class="special">)</span><span class="special">;</span>
<span class="comment">// <a class="link" href="discrete_distribution/param_type.html#idp59390536-bb">public member functions</a></span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">WeightType</span> <span class="special">></span> <a class="link" href="discrete_distribution/param_type.html#idp59390744-bb"><span class="identifier">probabilities</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="comment">// <a class="link" href="discrete_distribution/param_type.html#idp59430712-bb">friend functions</a></span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> CharT<span class="special">,</span> <span class="keyword">typename</span> Traits<span class="special">></span>
<span class="keyword">friend</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span>
<a class="link" href="discrete_distribution/param_type.html#idp59430920-bb"><span class="keyword">operator</span><span class="special"><<</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> CharT<span class="special">,</span> <span class="keyword">typename</span> Traits<span class="special">></span>
<span class="keyword">friend</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span>
<a class="link" href="discrete_distribution/param_type.html#idp59433480-bb"><span class="keyword">operator</span><span class="special">>></span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">friend</span> <span class="keyword">bool</span> <a class="link" href="discrete_distribution/param_type.html#idp59488040-bb"><span class="keyword">operator</span><span class="special">==</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">friend</span> <span class="keyword">bool</span> <a class="link" href="discrete_distribution/param_type.html#idp59490168-bb"><span class="keyword">operator</span><span class="special">!=</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span>
<span class="comment">// <a class="link" href="discrete_distribution.html#boost.random.discrete_distributionconstruct-copy-destruct">construct/copy/destruct</a></span>
<a class="link" href="discrete_distribution.html#idp59501704-bb"><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Iter<span class="special">></span> <a class="link" href="discrete_distribution.html#idp59504888-bb"><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="identifier">Iter</span><span class="special">,</span> <span class="identifier">Iter</span><span class="special">)</span><span class="special">;</span>
<a class="link" href="discrete_distribution.html#idp59507240-bb"><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">initializer_list</span><span class="special"><</span> <span class="identifier">WeightType</span> <span class="special">></span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Range<span class="special">></span> <span class="keyword">explicit</span> <a class="link" href="discrete_distribution.html#idp59480760-bb"><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">Range</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Func<span class="special">></span>
<a class="link" href="discrete_distribution.html#idp59482504-bb"><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="keyword">double</span><span class="special">,</span> <span class="keyword">double</span><span class="special">,</span> <span class="identifier">Func</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">explicit</span> <a class="link" href="discrete_distribution.html#idp59472536-bb"><span class="identifier">discrete_distribution</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="comment">// <a class="link" href="discrete_distribution.html#idp59484536-bb">public member functions</a></span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> URNG<span class="special">></span> <span class="identifier">IntType</span> <a class="link" href="discrete_distribution.html#idp59484744-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">URNG</span> <span class="special">&</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> URNG<span class="special">></span> <span class="identifier">IntType</span> <a class="link" href="discrete_distribution.html#idp59486616-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">URNG</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">result_type</span> <a class="link" href="discrete_distribution.html#idp59496200-bb"><span class="identifier">min</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">result_type</span> <a class="link" href="discrete_distribution.html#idp59496920-bb"><span class="identifier">max</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">WeightType</span> <span class="special">></span> <a class="link" href="discrete_distribution.html#idp59497640-bb"><span class="identifier">probabilities</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <a class="link" href="discrete_distribution.html#idp59498888-bb"><span class="identifier">param</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="keyword">void</span> <a class="link" href="discrete_distribution.html#idp59499656-bb"><span class="identifier">param</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">void</span> <a class="link" href="discrete_distribution.html#idp59500920-bb"><span class="identifier">reset</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="comment">// <a class="link" href="discrete_distribution.html#idp59473912-bb">friend functions</a></span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> CharT<span class="special">,</span> <span class="keyword">typename</span> Traits<span class="special">></span>
<span class="keyword">friend</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span>
<a class="link" href="discrete_distribution.html#idp59474120-bb"><span class="keyword">operator</span><span class="special"><<</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span>
<span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> CharT<span class="special">,</span> <span class="keyword">typename</span> Traits<span class="special">></span>
<span class="keyword">friend</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span>
<a class="link" href="discrete_distribution.html#idp59476696-bb"><span class="keyword">operator</span><span class="special">>></span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span>
<span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">friend</span> <span class="keyword">bool</span> <a class="link" href="discrete_distribution.html#idp59479272-bb"><span class="keyword">operator</span><span class="special">==</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span><span class="special">,</span>
<span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">friend</span> <span class="keyword">bool</span> <a class="link" href="discrete_distribution.html#idp59533000-bb"><span class="keyword">operator</span><span class="special">!=</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span><span class="special">,</span>
<span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="idp191527768"></a><h2>Description</h2>
<p>The class <code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code> models a <a class="link" href="../../boost_random/reference.html#boost_random.reference.concepts.random_distribution" title="Random Distribution">random distribution</a> . It produces integers in the range [0, n) with the probability of producing each value is specified by the parameters of the distribution. </p>
<div class="refsect2">
<a name="idp191529464"></a><h3>
<a name="boost.random.discrete_distributionconstruct-copy-destruct"></a><code class="computeroutput">discrete_distribution</code>
public
construct/copy/destruct</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
<pre class="literallayout"><a name="idp59501704-bb"></a><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Creates a new <code class="computeroutput"><code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code></code> object that has <span class="inlinemediaobject"><img src="../../images/random//form_3.png"></span> and <span class="inlinemediaobject"><img src="../../images/random//form_4.png"></span>. </p>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Iter<span class="special">></span> <a name="idp59504888-bb"></a><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="identifier">Iter</span> first<span class="special">,</span> <span class="identifier">Iter</span> last<span class="special">)</span><span class="special">;</span></pre>
<p>Constructs a <code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code> from an iterator range. If <code class="computeroutput">first</code> == <code class="computeroutput">last</code>, equivalent to the default constructor. Otherwise, the values of the range represent weights for the possible values of the distribution. </p>
</li>
<li class="listitem">
<pre class="literallayout"><a name="idp59507240-bb"></a><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">initializer_list</span><span class="special"><</span> <span class="identifier">WeightType</span> <span class="special">></span> wl<span class="special">)</span><span class="special">;</span></pre>
<p>Constructs a <code class="computeroutput"><code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code></code> from a <code class="computeroutput">std::initializer_list</code>. If the <code class="computeroutput">initializer_list</code> is empty, equivalent to the default constructor. Otherwise, the values of the <code class="computeroutput">initializer_list</code> represent weights for the possible values of the distribution. For example, given the distribution</p>
<pre class="programlisting">* discrete_distribution<> dist{1, 4, 5};
*
</pre>
<p>The probability of a 0 is 1/10, the probability of a 1 is 2/5, the probability of a 2 is 1/2, and no other values are possible. </p>
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<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Range<span class="special">></span> <span class="keyword">explicit</span> <a name="idp59480760-bb"></a><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">Range</span> <span class="special">&</span> range<span class="special">)</span><span class="special">;</span></pre>
<p>Constructs a <code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code> from a Boost.Range range. If the range is empty, equivalent to the default constructor. Otherwise, the values of the range represent weights for the possible values of the distribution. </p>
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<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Func<span class="special">></span>
<a name="idp59482504-bb"></a><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> nw<span class="special">,</span> <span class="keyword">double</span> xmin<span class="special">,</span> <span class="keyword">double</span> xmax<span class="special">,</span> <span class="identifier">Func</span> fw<span class="special">)</span><span class="special">;</span></pre>
<p>Constructs a <code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code> that approximates a function. If nw is zero, equivalent to the default constructor. Otherwise, the range of the distribution is [0, nw), and the weights are found by calling fw with values evenly distributed between <span class="inlinemediaobject"><img src="../../images/random//form_5.png"></span> and <span class="inlinemediaobject"><img src="../../images/random//form_6.png"></span>, where <span class="inlinemediaobject"><img src="../../images/random//form_7.png"></span>. </p>
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<pre class="literallayout"><span class="keyword">explicit</span> <a name="idp59472536-bb"></a><span class="identifier">discrete_distribution</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span> param<span class="special">)</span><span class="special">;</span></pre>
<p>Constructs a <code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code> from its parameters. </p>
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<div class="refsect2">
<a name="idp191568152"></a><h3>
<a name="idp59484536-bb"></a><code class="computeroutput">discrete_distribution</code> public member functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
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<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> URNG<span class="special">></span> <span class="identifier">IntType</span> <a name="idp59484744-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">URNG</span> <span class="special">&</span> urng<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns a value distributed according to the parameters of the <code class="computeroutput"><a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a></code>. </p>
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<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> URNG<span class="special">></span>
<span class="identifier">IntType</span> <a name="idp59486616-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">URNG</span> <span class="special">&</span> urng<span class="special">,</span> <span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span> param<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns a value distributed according to the parameters specified by param. </p>
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<pre class="literallayout"><span class="identifier">result_type</span> <a name="idp59496200-bb"></a><span class="identifier">min</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns the smallest value that the distribution can produce. </p>
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<pre class="literallayout"><span class="identifier">result_type</span> <a name="idp59496920-bb"></a><span class="identifier">max</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns the largest value that the distribution can produce. </p>
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<pre class="literallayout"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">WeightType</span> <span class="special">></span> <a name="idp59497640-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>
<p>Returns a vector containing the probabilities of each value of the distribution. For example, given</p>
<pre class="programlisting">* discrete_distribution<> dist = { 1, 4, 5 };
* std::vector<double> p = dist.param();
*
</pre>
<p>the vector, p will contain {0.1, 0.4, 0.5}. </p>
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<pre class="literallayout"><a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <a name="idp59498888-bb"></a><span class="identifier">param</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns the parameters of the distribution. </p>
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<pre class="literallayout"><span class="keyword">void</span> <a name="idp59499656-bb"></a><span class="identifier">param</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution/param_type.html" title="Class param_type">param_type</a> <span class="special">&</span> param<span class="special">)</span><span class="special">;</span></pre>
<p>Sets the parameters of the distribution. </p>
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<pre class="literallayout"><span class="keyword">void</span> <a name="idp59500920-bb"></a><span class="identifier">reset</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Effects: Subsequent uses of the distribution do not depend on values produced by any engine prior to invoking reset. </p>
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<div class="refsect2">
<a name="idp191599912"></a><h3>
<a name="idp59473912-bb"></a><code class="computeroutput">discrete_distribution</code> friend functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
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<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> CharT<span class="special">,</span> <span class="keyword">typename</span> Traits<span class="special">></span>
<span class="keyword">friend</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span>
<a name="idp59474120-bb"></a><span class="keyword">operator</span><span class="special"><<</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span> os<span class="special">,</span>
<span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span> dd<span class="special">)</span><span class="special">;</span></pre>
<p>Writes a distribution to a <code class="computeroutput">std::ostream</code>. </p>
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<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> CharT<span class="special">,</span> <span class="keyword">typename</span> Traits<span class="special">></span>
<span class="keyword">friend</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span>
<a name="idp59476696-bb"></a><span class="keyword">operator</span><span class="special">>></span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span> is<span class="special">,</span>
<span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span> dd<span class="special">)</span><span class="special">;</span></pre>
<p>Reads a distribution from a <code class="computeroutput">std::istream</code> </p>
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<pre class="literallayout"><span class="keyword">friend</span> <span class="keyword">bool</span> <a name="idp59479272-bb"></a><span class="keyword">operator</span><span class="special">==</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span> lhs<span class="special">,</span>
<span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span> rhs<span class="special">)</span><span class="special">;</span></pre>
<p>Returns true if the two distributions will return the same sequence of values, when passed equal generators. </p>
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<pre class="literallayout"><span class="keyword">friend</span> <span class="keyword">bool</span> <a name="idp59533000-bb"></a><span class="keyword">operator</span><span class="special">!=</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span> lhs<span class="special">,</span>
<span class="keyword">const</span> <a class="link" href="discrete_distribution.html" title="Class template discrete_distribution">discrete_distribution</a> <span class="special">&</span> rhs<span class="special">)</span><span class="special">;</span></pre>
<p>Returns true if the two distributions may return different sequences of values, when passed equal generators. </p>
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</ol></div>
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<td align="right"><div class="copyright-footer">Copyright © 2000-2005 Jens Maurer<br>Copyright © 2009, 2010 Steven Watanabe<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
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