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<div class="title">std::poisson_distribution< _IntType > Class Template Reference<div class="ingroups"><a class="el" href="a01211.html">Poisson Distributions</a></div></div> </div>
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<p>A discrete Poisson random number distribution.
<a href="a00660.html#details">More...</a></p>
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<li>struct <a class="el" href="a00661.html">param_type</a>
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Public Types</h2>
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<li>typedef _IntType <a class="el" href="a00660.html#a4c3d7ee8432d89d43749cb2c0aa7a588">result_type</a>
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Public Member Functions</h2>
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<li><a class="anchor" id="a750b39e44f386dc05574eb60a4044189"></a><!-- doxytag: member="std::poisson_distribution::poisson_distribution" ref="a750b39e44f386dc05574eb60a4044189" args="(double __mean=1.0)" -->
<b>poisson_distribution</b> (double __mean=1.0)
<li><a class="anchor" id="ae13d9eba8cae94119a0b0a003072fbc2"></a><!-- doxytag: member="std::poisson_distribution::poisson_distribution" ref="ae13d9eba8cae94119a0b0a003072fbc2" args="(const param_type &__p)" -->
<b>poisson_distribution</b> (const <a class="el" href="a00661.html">param_type</a> &__p)
<li><a class="el" href="a00660.html#a4c3d7ee8432d89d43749cb2c0aa7a588">result_type</a> <a class="el" href="a00660.html#af52804ef9c9e4242cedcd6782169cd78">max</a> () const
<li>double <a class="el" href="a00660.html#a239484069ed9b20e5d6949c2c42db989">mean</a> () const
<li><a class="el" href="a00660.html#a4c3d7ee8432d89d43749cb2c0aa7a588">result_type</a> <a class="el" href="a00660.html#a5faf76eff45d2171d40deaa8ab3c807e">min</a> () const
<li>template<typename _UniformRandomNumberGenerator > <a class="el" href="a00660.html#a4c3d7ee8432d89d43749cb2c0aa7a588">result_type</a> <a class="el" href="a00660.html#ad86771448473d2020de334628ddf6c18">operator()</a> (_UniformRandomNumberGenerator &__urng)
<li>template<typename _UniformRandomNumberGenerator > <a class="el" href="a00660.html#a4c3d7ee8432d89d43749cb2c0aa7a588">result_type</a> <a class="el" href="a00660.html#af3d2581282eefd6412d41b50dad2a9a0">operator()</a> (_UniformRandomNumberGenerator &__urng, const <a class="el" href="a00661.html">param_type</a> &__p)
<li><a class="el" href="a00661.html">param_type</a> <a class="el" href="a00660.html#af9de79858d221c5e490045740dda9954">param</a> () const
<li>void <a class="el" href="a00660.html#ac0233f87c798faa09a5cbeb91969bd8c">param</a> (const <a class="el" href="a00661.html">param_type</a> &__param)
<li>void <a class="el" href="a00660.html#a22ecafd7d767621e777f6e8e556ff453">reset</a> ()
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<h2><a name="friends"></a>
Friends</h2>
<ul>
<li>template<typename _IntType1 , typename _CharT , typename _Traits > <a class="el" href="a00251.html">std::basic_ostream</a>< _CharT, <br class="typebreak"/>
_Traits > & <a class="el" href="a00660.html#a615575243ba55d15322e32dfe6fe9e49">operator<<</a> (<a class="el" href="a00251.html">std::basic_ostream</a>< _CharT, _Traits > &, const <a class="el" href="a00660.html">std::poisson_distribution</a>< _IntType1 > &)
<li>template<typename _IntType1 > bool <a class="el" href="a00660.html#a532b302048bbc253a4ee6687582b1bdb">operator==</a> (const <a class="el" href="a00660.html">std::poisson_distribution</a>< _IntType1 > &__d1, const <a class="el" href="a00660.html">std::poisson_distribution</a>< _IntType1 > &__d2)
<li>template<typename _IntType1 , typename _CharT , typename _Traits > <a class="el" href="a00250.html">std::basic_istream</a>< _CharT, <br class="typebreak"/>
_Traits > & <a class="el" href="a00660.html#a821e7d1b6824496fd0625a6323bc25ea">operator>></a> (<a class="el" href="a00250.html">std::basic_istream</a>< _CharT, _Traits > &, <a class="el" href="a00660.html">std::poisson_distribution</a>< _IntType1 > &)
</ul>
<hr/><a name="details" id="details"></a><h2>Detailed Description</h2>
<div class="textblock"><h3>template<typename _IntType = int><br/>
class std::poisson_distribution< _IntType ></h3>
<p>A discrete Poisson random number distribution. </p>
<p>The formula for the Poisson probability density function is <img class="formulaInl" alt="$p(i|\mu) = \frac{\mu^i}{i!} e^{-\mu}$" src="form_19.png"/> where <img class="formulaInl" alt="$\mu$" src="form_20.png"/> is the parameter of the distribution. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l03957">3957</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
</div><hr/><h2>Member Typedef Documentation</h2>
<a class="anchor" id="a4c3d7ee8432d89d43749cb2c0aa7a588"></a><!-- doxytag: member="std::poisson_distribution::result_type" ref="a4c3d7ee8432d89d43749cb2c0aa7a588" args="" -->
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template<typename _IntType = int> </div>
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<td class="memname">typedef _IntType <a class="el" href="a00660.html">std::poisson_distribution</a>< _IntType >::<a class="el" href="a00660.html#a4c3d7ee8432d89d43749cb2c0aa7a588">result_type</a></td>
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<p>The type of the range of the distribution. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l03964">3964</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
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<hr/><h2>Member Function Documentation</h2>
<a class="anchor" id="af52804ef9c9e4242cedcd6782169cd78"></a><!-- doxytag: member="std::poisson_distribution::max" ref="af52804ef9c9e4242cedcd6782169cd78" args="() const " -->
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template<typename _IntType = int> </div>
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<p>Returns the least upper bound value of the distribution. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l04051">4051</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
<p>Referenced by <a class="el" href="a00998_source.html#l01434">std::binomial_distribution< _IntType >::operator()()</a>, and <a class="el" href="a00998_source.html#l01202">std::poisson_distribution< _IntType >::operator()()</a>.</p>
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<a class="anchor" id="a239484069ed9b20e5d6949c2c42db989"></a><!-- doxytag: member="std::poisson_distribution::mean" ref="a239484069ed9b20e5d6949c2c42db989" args="() const " -->
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<p>Returns the distribution parameter <code>mean</code>. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l04022">4022</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
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<a class="anchor" id="a5faf76eff45d2171d40deaa8ab3c807e"></a><!-- doxytag: member="std::poisson_distribution::min" ref="a5faf76eff45d2171d40deaa8ab3c807e" args="() const " -->
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template<typename _IntType = int> </div>
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<p>Returns the greatest lower bound value of the distribution. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l04044">4044</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
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<a class="anchor" id="af3d2581282eefd6412d41b50dad2a9a0"></a><!-- doxytag: member="std::poisson_distribution::operator()" ref="af3d2581282eefd6412d41b50dad2a9a0" args="(_UniformRandomNumberGenerator &__urng, const param_type &__p)" -->
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template<typename _IntType > </div>
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<td class="memname"><a class="el" href="a00660.html">poisson_distribution</a>< _IntType >::<a class="el" href="a00660.html#a4c3d7ee8432d89d43749cb2c0aa7a588">result_type</a> <a class="el" href="a00660.html">std::poisson_distribution</a>< _IntType >::operator() </td>
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<p>A rejection algorithm when mean >= 12 and a simple method based upon the multiplication of uniform random variates otherwise. NB: The former is available only if _GLIBCXX_USE_C99_MATH_TR1 is defined.</p>
<p>Reference: Devroye, L. Non-Uniform Random Variates Generation. Springer-Verlag, New York, 1986, Ch. X, Sects. 3.3 & 3.4 (+ Errata!). </p>
<p>Definition at line <a class="el" href="a00998_source.html#l01202">1202</a> of file <a class="el" href="a00998_source.html">random.tcc</a>.</p>
<p>References <a class="el" href="a00812_source.html#l00596">std::abs()</a>, <a class="el" href="a00812_source.html#l00784">std::log()</a>, and <a class="el" href="a00997_source.html#l04051">std::poisson_distribution< _IntType >::max()</a>.</p>
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<a class="anchor" id="ad86771448473d2020de334628ddf6c18"></a><!-- doxytag: member="std::poisson_distribution::operator()" ref="ad86771448473d2020de334628ddf6c18" args="(_UniformRandomNumberGenerator &__urng)" -->
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template<typename _IntType = int> </div>
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<td class="memname"><a class="el" href="a00660.html#a4c3d7ee8432d89d43749cb2c0aa7a588">result_type</a> <a class="el" href="a00660.html">std::poisson_distribution</a>< _IntType >::operator() </td>
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<p>Generating functions. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l04059">4059</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
<p>References <a class="el" href="a00997_source.html#l04059">std::poisson_distribution< _IntType >::operator()()</a>, and <a class="el" href="a00997_source.html#l04029">std::poisson_distribution< _IntType >::param()</a>.</p>
<p>Referenced by <a class="el" href="a00997_source.html#l04059">std::poisson_distribution< _IntType >::operator()()</a>.</p>
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<a class="anchor" id="af9de79858d221c5e490045740dda9954"></a><!-- doxytag: member="std::poisson_distribution::param" ref="af9de79858d221c5e490045740dda9954" args="() const " -->
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<p>Returns the parameter set of the distribution. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l04029">4029</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
<p>Referenced by <a class="el" href="a00997_source.html#l04059">std::poisson_distribution< _IntType >::operator()()</a>.</p>
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<a class="anchor" id="ac0233f87c798faa09a5cbeb91969bd8c"></a><!-- doxytag: member="std::poisson_distribution::param" ref="ac0233f87c798faa09a5cbeb91969bd8c" args="(const param_type &__param)" -->
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<p>Sets the parameter set of the distribution. </p>
<dl><dt><b>Parameters:</b></dt><dd>
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<tr><td class="paramname">__param</td><td>The new parameter set of the distribution. </td></tr>
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<p>Definition at line <a class="el" href="a00997_source.html#l04037">4037</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
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<a class="anchor" id="a22ecafd7d767621e777f6e8e556ff453"></a><!-- doxytag: member="std::poisson_distribution::reset" ref="a22ecafd7d767621e777f6e8e556ff453" args="()" -->
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<p>Resets the distribution state. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l04015">4015</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
<p>References <a class="el" href="a00997_source.html#l02031">std::normal_distribution< _RealType >::reset()</a>.</p>
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<hr/><h2>Friends And Related Function Documentation</h2>
<a class="anchor" id="a615575243ba55d15322e32dfe6fe9e49"></a><!-- doxytag: member="std::poisson_distribution::operator<<" ref="a615575243ba55d15322e32dfe6fe9e49" args="(std::basic_ostream< _CharT, _Traits > &, const std::poisson_distribution< _IntType1 > &)" -->
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<p>Inserts a poisson_distribution random number distribution <code>__x</code> into the output stream <code>__os</code>. </p>
<dl><dt><b>Parameters:</b></dt><dd>
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<dl class="return"><dt><b>Returns:</b></dt><dd>The output stream with the state of <code>__x</code> inserted or in an error state. </dd></dl>
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<a class="anchor" id="a532b302048bbc253a4ee6687582b1bdb"></a><!-- doxytag: member="std::poisson_distribution::operator==" ref="a532b302048bbc253a4ee6687582b1bdb" args="(const std::poisson_distribution< _IntType1 > &__d1, const std::poisson_distribution< _IntType1 > &__d2)" -->
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<p>Return true if two Poisson distributions have the same parameters and the sequences that would be generated are equal. </p>
<p>Definition at line <a class="el" href="a00997_source.html#l04074">4074</a> of file <a class="el" href="a00997_source.html">random.h</a>.</p>
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<a class="anchor" id="a821e7d1b6824496fd0625a6323bc25ea"></a><!-- doxytag: member="std::poisson_distribution::operator>>" ref="a821e7d1b6824496fd0625a6323bc25ea" args="(std::basic_istream< _CharT, _Traits > &, std::poisson_distribution< _IntType1 > &)" -->
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<p>Extracts a poisson_distribution random number distribution <code>__x</code> from the input stream <code>__is</code>. </p>
<dl><dt><b>Parameters:</b></dt><dd>
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<tr><td class="paramname">__is</td><td>An input stream. </td></tr>
<tr><td class="paramname">__x</td><td>A poisson_distribution random number generator engine.</td></tr>
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<dl class="return"><dt><b>Returns:</b></dt><dd>The input stream with <code>__x</code> extracted or in an error state. </dd></dl>
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<hr/>The documentation for this class was generated from the following files:<ul>
<li><a class="el" href="a00997_source.html">random.h</a></li>
<li><a class="el" href="a00998_source.html">random.tcc</a></li>
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