SSJ
V. labo.

umontreal.iro.lecuyer.randvar
Class PoissonGen

java.lang.Object
  extended by umontreal.iro.lecuyer.randvar.RandomVariateGen
      extended by umontreal.iro.lecuyer.randvar.RandomVariateGenInt
          extended by umontreal.iro.lecuyer.randvar.PoissonGen
Direct Known Subclasses:
PoissonTIACGen

public class PoissonGen
extends RandomVariateGenInt

This class implements random variate generators having the Poisson distribution. Its mass function is

p(x) = e-λλx/(x!) for x = 0, 1,...

where λ > 0 is a real valued parameter equal to the mean.

No local copy of the parameter λ = lambda is maintained in this class. The (non-static) nextInt method simply calls inverseF on the distribution.


Constructor Summary
PoissonGen(RandomStream s, double lambda)
          Creates a Poisson random variate generator with parameter λ = lambda, using stream s.
PoissonGen(RandomStream s, PoissonDist dist)
          Creates a new random variate generator using the Poisson distribution dist and stream s.
 
Method Summary
 double getLambda()
          Returns the λ associated with this object.
static int nextInt(RandomStream s, double lambda)
          A static method for generating a random variate from a Poisson distribution with parameter λ = lambda.
 
Methods inherited from class umontreal.iro.lecuyer.randvar.RandomVariateGenInt
getDistribution, nextArrayOfInt, nextInt
 
Methods inherited from class umontreal.iro.lecuyer.randvar.RandomVariateGen
getStream, nextArrayOfDouble, nextDouble, setStream, toString
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

PoissonGen

public PoissonGen(RandomStream s,
                  double lambda)
Creates a Poisson random variate generator with parameter λ = lambda, using stream s.


PoissonGen

public PoissonGen(RandomStream s,
                  PoissonDist dist)
Creates a new random variate generator using the Poisson distribution dist and stream s.

Method Detail

nextInt

public static int nextInt(RandomStream s,
                          double lambda)
A static method for generating a random variate from a Poisson distribution with parameter λ = lambda.


getLambda

public double getLambda()
Returns the λ associated with this object.


SSJ
V. labo.

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