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71<h1>itpp::Gamma_RNG Class Reference<br>
72<small>
73[<a class="el" href="group__randgen.html">Random Number Generation</a>]</small>
74</h1><!-- doxytag: class="itpp::Gamma_RNG" -->Gamma distribution<p>
75Generate samples from Gamma(alpha,beta) density, according to the following equation: <p class="formulaDsp">
76<img class="formulaDsp" alt="\[ x \sim \Gamma(\alpha,\beta) = \frac{\beta^\alpha}{\Gamma(\alpha)}x^{\alpha-1} \exp(-\beta x) \]" src="form_184.png">
77<p>
78. 
79<a href="#_details">More...</a>
80<p>
81<code>#include &lt;<a class="el" href="random_8h-source.html">random.h</a>&gt;</code>
82<p>
83
84<p>
85<a href="classitpp_1_1Gamma__RNG-members.html">List of all members.</a><table border="0" cellpadding="0" cellspacing="0">
86<tr><td></td></tr>
87<tr><td colspan="2"><br><h2>Public Member Functions</h2></td></tr>
88<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="e132860f825f427d63652edd02c25b54"></a><!-- doxytag: member="itpp::Gamma_RNG::Gamma_RNG" ref="e132860f825f427d63652edd02c25b54" args="(double a=1.0, double b=1.0)" -->
89&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="classitpp_1_1Gamma__RNG.html#e132860f825f427d63652edd02c25b54">Gamma_RNG</a> (double a=1.0, double b=1.0)</td></tr>
90
91<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Constructor, which sets alpha (a) and beta (b). <br></td></tr>
92<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="cced56e9bb421619b7ff32fbf794d501"></a><!-- doxytag: member="itpp::Gamma_RNG::setup" ref="cced56e9bb421619b7ff32fbf794d501" args="(double a, double b)" -->
93void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="classitpp_1_1Gamma__RNG.html#cced56e9bb421619b7ff32fbf794d501">setup</a> (double a, double b)</td></tr>
94
95<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Set alpha and beta. <br></td></tr>
96<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="98e2e65456bca33fca602b2bd607235e"></a><!-- doxytag: member="itpp::Gamma_RNG::operator()" ref="98e2e65456bca33fca602b2bd607235e" args="()" -->
97double&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="classitpp_1_1Gamma__RNG.html#98e2e65456bca33fca602b2bd607235e">operator()</a> ()</td></tr>
98
99<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get one sample. <br></td></tr>
100<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="d407bbcda8a39e3f07cac3fdf58ca430"></a><!-- doxytag: member="itpp::Gamma_RNG::operator()" ref="d407bbcda8a39e3f07cac3fdf58ca430" args="(int n)" -->
101vec&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="classitpp_1_1Gamma__RNG.html#d407bbcda8a39e3f07cac3fdf58ca430">operator()</a> (int n)</td></tr>
102
103<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get a sample vector. <br></td></tr>
104<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="394c84c73fe7e507c04fe6a9f64067ac"></a><!-- doxytag: member="itpp::Gamma_RNG::operator()" ref="394c84c73fe7e507c04fe6a9f64067ac" args="(int r, int c)" -->
105mat&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="classitpp_1_1Gamma__RNG.html#394c84c73fe7e507c04fe6a9f64067ac">operator()</a> (int r, int c)</td></tr>
106
107<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get a sample matrix. <br></td></tr>
108<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="d79da7d042746e5aeb1a5b03976dda75"></a><!-- doxytag: member="itpp::Gamma_RNG::sample" ref="d79da7d042746e5aeb1a5b03976dda75" args="()" -->
109double&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="classitpp_1_1Gamma__RNG.html#d79da7d042746e5aeb1a5b03976dda75">sample</a> ()</td></tr>
110
111<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get a sample. <br></td></tr>
112</table>
113<hr><a name="_details"></a><h2>Detailed Description</h2>
114Gamma distribution<p>
115Generate samples from Gamma(alpha,beta) density, according to the following equation: <p class="formulaDsp">
116<img class="formulaDsp" alt="\[ x \sim \Gamma(\alpha,\beta) = \frac{\beta^\alpha}{\Gamma(\alpha)}x^{\alpha-1} \exp(-\beta x) \]" src="form_184.png">
117<p>
118.
119<p>
120For <img class="formulaInl" alt="$\alpha=1$" src="form_185.png"> the Gamma distribution is equivalent to the Exponential distribution.<p>
121<dl class="note" compact><dt><b>Note:</b></dt><dd>The implementation of the <a class="el" href="classitpp_1_1Gamma__RNG.html#d79da7d042746e5aeb1a5b03976dda75" title="Get a sample.">sample()</a> function was adapted from the R statistical language. </dd></dl>
122<dl class="author" compact><dt><b>Author:</b></dt><dd>Vasek Smidl </dd></dl>
123<hr>The documentation for this class was generated from the following files:<ul>
124<li><a class="el" href="random_8h-source.html">random.h</a><li><a class="el" href="random_8cpp.html">random.cpp</a></ul>
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