sim.util.distribution
Class Zeta

java.lang.Object
  sim.util.distribution.AbstractDistribution
      sim.util.distribution.AbstractDiscreteDistribution
          sim.util.distribution.Zeta

All Implemented Interfaces:

java.io.Serializable

public class Zeta
extends AbstractDiscreteDistribution

Zeta distribution.

Valid parameter ranges: ro > 0 and pk >= 0.

If either ro > 100 or k > 10000 numerical problems in computing the theoretical moments arise, therefore ro <= 100 and k <= 10000 are recommended.

Instance methods operate on a user supplied uniform random number generator; they are unsynchronized.

Static methods operate on a default uniform random number generator; they are synchronized.

Implementation:

Method: Acceptance/Rejection. High performance implementation.

This is a port and adaption of Zeta.c from the C-RAND / WIN-RAND library. C-RAND's implementation, in turn, is based upon

J. Dagpunar (1988): Principles of Random Variate Generation, Clarendon Press, Oxford.

See Also:

Serialized Form

Field Summary

protected double	c
protected double	d
protected double	maxlongint
protected double	pk
protected double	pk_prev
protected double	ro
protected double	ro_prev

Fields inherited from class sim.util.distribution.AbstractDistribution

randomGenerator

Constructor Summary

Zeta(double ro, double pk, MersenneTwisterFast randomGenerator)
Constructs a Zeta distribution.

Method Summary

protected long	generateZeta(double ro, double pk, MersenneTwisterFast randomGenerator) Returns a zeta distributed random number.
int	nextInt() Returns a random number from the distribution.
void	setState(double ro, double pk) Sets the parameters.
java.lang.String	toString() Returns a String representation of the receiver.

Methods inherited from class sim.util.distribution.AbstractDiscreteDistribution

nextDouble

Methods inherited from class sim.util.distribution.AbstractDistribution

apply, apply, getRandomGenerator, setRandomGenerator

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

ro

protected double ro

pk

protected double pk

c

protected double c

d

protected double d

ro_prev

protected double ro_prev

pk_prev

protected double pk_prev

maxlongint

protected double maxlongint

Constructor Detail

Zeta

public Zeta(double ro,
            double pk,
            MersenneTwisterFast randomGenerator)

Constructs a Zeta distribution.

Method Detail

generateZeta

protected long generateZeta(double ro,
                            double pk,
                            MersenneTwisterFast randomGenerator)

Returns a zeta distributed random number.

nextInt

public int nextInt()

Returns a random number from the distribution.

Specified by:

nextInt in class AbstractDiscreteDistribution

setState

public void setState(double ro,
                     double pk)

Sets the parameters.

toString

public java.lang.String toString()

Returns a String representation of the receiver.

Overrides:

toString in class java.lang.Object