umontreal.iro.lecuyer.randvar

Class LogisticGen

java.lang.Object

umontreal.iro.lecuyer.randvar.RandomVariateGen

umontreal.iro.lecuyer.randvar.LogisticGen

public class LogisticGen
extends RandomVariateGen

This class implements random variate generators for the logistic distribution. Its parameters are α and λ > 0. Its density function is

f (x) = λe^-λ(x-α)/[(1 + e^-λ(x-α))²] for - ∞ < x < ∞.

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

Constructor Summary

Constructors

Constructor and Description
LogisticGen(RandomStream s) Creates a logistic random variate generator with parameters α = 0 and λ = 1, using stream s.
LogisticGen(RandomStream s, double alpha, double lambda) Creates a logistic random variate generator with parameters α = alpha and λ = lambda, using stream s.
LogisticGen(RandomStream s, LogisticDist dist) Creates a new generator for the logistic distribution dist and stream s.

Method Summary

Modifier and Type	Method and Description
double	getAlpha() Returns the parameter α of this object.
double	getLambda() Returns the parameter λ of this object.
static double	nextDouble(RandomStream s, double alpha, double lambda) Generates a new variate from the logistic distribution with parameters α = alpha and λ = lambda, using stream s.

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

LogisticGen

public LogisticGen(RandomStream s,
                   double alpha,
                   double lambda)

Creates a logistic random variate generator with parameters α = alpha and λ = lambda, using stream s.

LogisticGen

public LogisticGen(RandomStream s)

Creates a logistic random variate generator with parameters α = 0 and λ = 1, using stream s.

LogisticGen

public LogisticGen(RandomStream s,
                   LogisticDist dist)

Creates a new generator for the logistic distribution dist and stream s.

Method Detail

nextDouble

public static double nextDouble(RandomStream s,
                                double alpha,
                                double lambda)

Generates a new variate from the logistic distribution with parameters α = alpha and λ = lambda, using stream s.

getAlpha

public double getAlpha()

Returns the parameter α of this object.

getLambda

public double getLambda()

Returns the parameter λ of this object.