cz.zcu.fav.kiv.jsim.random
Class JSimGaussianStream

java.lang.Object
  cz.zcu.fav.kiv.jsim.random.JSimGaussianStream

public class JSimGaussianStream
extends java.lang.Object

A stream generating random real values with a Gaussian (aka normal) distribution with given mu and sigma. The two parameters are set by the user when the stream is constructed. An initial seed can be specified, which allows you to generate the same sequence of random values several times. A complex description of Gaussian (normal) distribution can be found at Wolfram Research Math World pages.

Since:

J-Sim version 0.3.0

Version:

J-Sim version 0.6.0

Author:

Jarda KAČER

Field Summary

private double	mu The mu parameter of the distribution, equal to the mean value.
private double	sigma The sigma parameter of the distribution, equal to the square root of the variance.
protected JSimUniformStream	stream An internal stream from which random numbers are taken and modified.

Constructor Summary

JSimGaussianStream(double mu, double sigma)
Creates a new stream generating random real values with Gaussian distribution.

JSimGaussianStream(double mu, double sigma, long seed)
Creates a new stream generating random real values with Gaussian distribution.

Method Summary

double	getMu() Returns the mu parameter of the distribution.
double	getNext() Returns a randomly generated real value having Gaussian distribution with the given mu and sigma parameters.
double	getSigma() Returns the sigma parameter of the distribution.

Methods inherited from class java.lang.Object

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

Field Detail

stream

protected JSimUniformStream stream

An internal stream from which random numbers are taken and modified. Because we need the stream to generate values with a uniform distribution from <0,1>, JSimUniformStream is used instead the classic Java Random.

mu

private double mu

The mu parameter of the distribution, equal to the mean value.

sigma

private double sigma

The sigma parameter of the distribution, equal to the square root of the variance.

Constructor Detail

JSimGaussianStream

public JSimGaussianStream(double mu,
                          double sigma)
                   throws JSimInvalidParametersException

Creates a new stream generating random real values with Gaussian distribution. A pseudo-randomly generated seed will be used.

Parameters:

mu - The mu parameter of the distribution, equal to the mean value.

sigma - The sigma parameter of the distribution, equal to the square root of the variance.

Throws:

JSimInvalidParametersException - This exception is thrown out if sigma is less than 0.

JSimGaussianStream

public JSimGaussianStream(double mu,
                          double sigma,
                          long seed)
                   throws JSimInvalidParametersException

Creates a new stream generating random real values with Gaussian distribution. The seed given as the third argument will be used.

Parameters:

mu - The mu parameter of the distribution, equal to the mean value.

sigma - The sigma parameter of the distribution, equal to the square root of the variance.

seed - A seed that will initialize the generator.

Throws:

JSimInvalidParametersException - This exception is thrown out if sigma is less than 0.

Method Detail

getNext

public double getNext()

Returns a randomly generated real value having Gaussian distribution with the given mu and sigma parameters.

Returns:

A random real value with Gaussian distribution.

getMu

public double getMu()

Returns the mu parameter of the distribution.

Returns:

The mu parameter of the distribution.

getSigma

public double getSigma()

Returns the sigma parameter of the distribution.

Returns:

The sigma parameter of the distribution.