SSJ
V. 1.2.5.

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, PoissonDist dist)
          Creates a new random variate generator using the Poisson distribution dist and stream s.
 
Method Summary
 int nextInt()
          Generates a random number (an integer) from the discrete distribution contained in 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
nextArrayOfInt
 
Methods inherited from class umontreal.iro.lecuyer.randvar.RandomVariateGen
getDistribution, getStream, nextArrayOfDouble, nextDouble, setStream
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

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 int nextInt()
Description copied from class: RandomVariateGenInt
Generates a random number (an integer) from the discrete distribution contained in this object. By default, this method uses inversion by calling the inverseF method of the distribution object. Alternative generating methods are provided in subclasses.

Overrides:
nextInt in class RandomVariateGenInt
Returns:
the generated value

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.


SSJ
V. 1.2.5.

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