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<html><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"><!--Converted with jLaTeX2HTML 2002 (1.62) JA patch-1.4patched version by: Kenshi Muto, Debian Project.LaTeX2HTML 2002 (1.62),original version by: Nikos Drakos, CBLU, University of Leeds* revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan* with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --><HTML><HEAD><TITLE>22.2 Random Variables</TITLE><META NAME="description" CONTENT="22.2 Random Variables"><META NAME="keywords" CONTENT="everything"><META NAME="resource-type" CONTENT="document"><META NAME="distribution" CONTENT="global"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"><META NAME="Generator" CONTENT="jLaTeX2HTML v2002 JA patch-1.4"><META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"><LINK REL="STYLESHEET" HREF="everything.css" tppabs="http://www.isi.edu/nsnam/ns/doc/everything.css"><LINK REL="next" HREF="node261.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node261.html"><LINK REL="previous" HREF="node248.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node248.html"><LINK REL="up" HREF="node247.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node247.html"><LINK REL="next" HREF="node261.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node261.html"></HEAD><BODY ><!--Navigation Panel--><A NAME="tex2html5294" HREF="node261.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node261.html"><IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="file:/usr/share/latex2html/icons/next.png"></A> <A NAME="tex2html5288" HREF="node247.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node247.html"><IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="file:/usr/share/latex2html/icons/up.png"></A> <A NAME="tex2html5282" HREF="node259.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node259.html"><IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="file:/usr/share/latex2html/icons/prev.png"></A> <A NAME="tex2html5290" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html"><IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="file:/usr/share/latex2html/icons/contents.png"></A> <A NAME="tex2html5292" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html"><IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="file:/usr/share/latex2html/icons/index.png"></A> <BR><B> Next:</B> <A NAME="tex2html5295" HREF="node261.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node261.html">22.3 Integrals</A><B> Up:</B> <A NAME="tex2html5289" HREF="node247.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node247.html">22. 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Each distribution is parameterized with the values ofappropriate parameters. The value method is used to return a valuefrom the distribution. <P>The currently defined distributions, and their associated parameters are:<P><TABLE CELLPADDING=3><TR><TD ALIGN="RIGHT">UniformRandomVariabletools/ranvar.h</TD><TD ALIGN="LEFT"><TT>min_</TT>, <TT>max_</TT></TD></TR><TR><TD ALIGN="RIGHT">ExponentialRandomVariabletools/ranvar.h</TD><TD ALIGN="LEFT"><TT>avg_</TT></TD></TR><TR><TD ALIGN="RIGHT">ParetoRandomVariabletools/ranvar.h</TD><TD ALIGN="LEFT"><TT>avg_</TT>, <TT>shape_</TT></TD></TR><TR><TD ALIGN="RIGHT">ParetoIIRandomVariabletools/ranvar.h</TD><TD ALIGN="LEFT"><TT>avg_</TT>, <TT>shape_</TT></TD></TR><TR><TD ALIGN="RIGHT">ConstantRandomVariabletools/ranvar.h</TD><TD ALIGN="LEFT"><TT>val_</TT></TD></TR><TR><TD ALIGN="RIGHT">HyperExponentialRandomVariabletools/ranvar.h</TD><TD ALIGN="LEFT"><TT>avg_</TT>, <TT>cov_</TT></TD></TR><TR><TD ALIGN="RIGHT">NormalRandomVariabletools/ranvar.h</TD><TD ALIGN="LEFT"><TT>avg_</TT>, <TT>std_</TT></TD></TR><TR><TD ALIGN="RIGHT">LogNormalRandomVariabletools/ranvar.h</TD><TD ALIGN="LEFT"><TT>avg_</TT>, <TT>std_</TT></TD></TR></TABLE><P>The RandomVariable class is available in OTcl. For instance, tocreate a random variable that generates number uniformly on [10, 20]:<PRE> set u [new RandomVariable/Uniform] $u set min_ 10 $u set max_ 20 $u value</PRE>By default, RandomVariable objects use the default random numbergenerator described in the previous section. The use-rng method canbe used to associate a RandomVariable with a non-default RNG:<PRE> set rng [new RNG] $rng seed 0 set e [new RandomVariable/Exponential] $e use-rng $rng</PRE><P><HR><!--Navigation Panel--><A NAME="tex2html5294" HREF="node261.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node261.html"><IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="file:/usr/share/latex2html/icons/next.png"></A> <A NAME="tex2html5288" HREF="node247.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node247.html"><IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="file:/usr/share/latex2html/icons/up.png"></A> <A NAME="tex2html5282" HREF="node259.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node259.html"><IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="file:/usr/share/latex2html/icons/prev.png"></A> <A NAME="tex2html5290" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html"><IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="file:/usr/share/latex2html/icons/contents.png"></A> <A NAME="tex2html5292" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html"><IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="file:/usr/share/latex2html/icons/index.png"></A> <BR><B> Next:</B> <A NAME="tex2html5295" HREF="node261.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node261.html">22.3 Integrals</A><B> Up:</B> <A NAME="tex2html5289" HREF="node247.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node247.html">22. 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