SSJ
V. labo.

umontreal.iro.lecuyer.randvar
Class ChiSquareGen

java.lang.Object
  extended by umontreal.iro.lecuyer.randvar.RandomVariateGen
      extended by umontreal.iro.lecuyer.randvar.ChiSquareGen

public class ChiSquareGen
extends RandomVariateGen

ChiSquareGen

This class implements random variate generators with the chi square distribution with n > 0 degrees of freedom. Its density function is

f (x) = xn/2-1e-x/2/(2n/2Γ(n/2)) for x > 0, 0 elsewhere

where Γ(x) is the gamma function defined in GammaGen.

The (non-static) nextDouble method simply calls inverseF on the distribution.


Constructor Summary
ChiSquareGen(RandomStream s, ChiSquareDist dist)
          .
ChiSquareGen(RandomStream s, int n)
          .
 
Method Summary
 int getN()
          .
static double nextDouble(RandomStream s, int n)
          .
 
Methods inherited from class umontreal.iro.lecuyer.randvar.RandomVariateGen
getDistribution, getStream, nextArrayOfDouble, nextDouble, setStream, toString
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ChiSquareGen

public ChiSquareGen(RandomStream s,
                    int n)
. \begin{tabb}Creates a \emph{chi square} random variate generator with
 $n$\ degrees of freedom, using stream \texttt{s}.
 \end{tabb}


ChiSquareGen

public ChiSquareGen(RandomStream s,
                    ChiSquareDist dist)
. \begin{tabb}Create a new generator for the distribution \texttt{dist}
 and stream \texttt{s}.
 \end{tabb}

Method Detail

nextDouble

public static double nextDouble(RandomStream s,
                                int n)
. \begin{tabb}Generates a new variate from the chi square distribution
 with $n$\ degrees of freedom, using stream \texttt{s}.
 \end{tabb}


getN

public int getN()
. \begin{tabb}
 Returns the value of $n$\ for this object.
 \end{tabb}

 


SSJ
V. labo.

To submit a bug or ask questions, send an e-mail to Pierre L'Ecuyer.