edu.uah.math.distributions
Class ChiSquareDistribution

java.lang.Object
  edu.uah.math.distributions.Distribution
      edu.uah.math.distributions.GammaDistribution
          edu.uah.math.distributions.ChiSquareDistribution

All Implemented Interfaces:

java.io.Serializable

public class ChiSquareDistribution
extends GammaDistribution
implements java.io.Serializable

This class defines the chi-square distribution with a specifed degrees of freedom parameter.

Version:

August, 2003

Author:

Kyle Siegrist, Dawn Duehring

See Also:

Serialized Form

Field Summary

Fields inherited from class edu.uah.math.distributions.Distribution

CONTINUOUS, DISCRETE, MIXED

Constructor Summary

ChiSquareDistribution()
This default constructor creates a new chi-square distribution with 1 degree of freedom.

ChiSquareDistribution(int n)
This general constructor creates a new chi-square distribuiton with a specified degrees of freedom parameter.

Method Summary

int	getDegrees() This method returns the degrees of freedom parameter.
void	setDegrees(int n) This method sets the degrees of freedom parameter and computes the defaut domain.
void	setParameters(double k, double b) This method sets the gamma parameters, which must be related to the degrees of freedom.
void	setScale(double b) This method sets the scale parameter, which must be 2.
void	setShape(double k) This method sets the shape parameter, which must be n/2, where n is the degrees of freedom.
double	simulate() This method simulates a value from the distribuiton, as the sum of squares of independent, standard normal distribution.
java.lang.String	toString() This method returns a string that gives the name of the distribution and the values of the parameters.

Methods inherited from class edu.uah.math.distributions.GammaDistribution

getCDF, getDensity, getMaxDensity, getMean, getMGF, getMoment, getMoment, getScale, getShape, getVariance

Methods inherited from class edu.uah.math.distributions.Distribution

getDomain, getFailureRate, getMedian, getPGF, getQuantile, getSD, getType, setDomain, setDomain

Methods inherited from class java.lang.Object

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

Constructor Detail

ChiSquareDistribution

public ChiSquareDistribution(int n)

This general constructor creates a new chi-square distribuiton with a specified degrees of freedom parameter.

Parameters:

n - the degrees of freedom

ChiSquareDistribution

public ChiSquareDistribution()

This default constructor creates a new chi-square distribution with 1 degree of freedom.

Method Detail

setDegrees

public void setDegrees(int n)

This method sets the degrees of freedom parameter and computes the defaut domain.

Parameters:

n - the degrees of freedom

getDegrees

public int getDegrees()

This method returns the degrees of freedom parameter.

Returns:

the degrees of freedom

simulate

public double simulate()

This method simulates a value from the distribuiton, as the sum of squares of independent, standard normal distribution.

Overrides:

simulate in class GammaDistribution

Returns:

a simulated value form the distribution

setShape

public void setShape(double k)

This method sets the shape parameter, which must be n/2, where n is the degrees of freedom.

Overrides:

setShape in class GammaDistribution

Parameters:

k - the shape parameter

setScale

public void setScale(double b)

This method sets the scale parameter, which must be 2.

Overrides:

setScale in class GammaDistribution

Parameters:

b - the scale parameter

setParameters

public void setParameters(double k,
                          double b)

This method sets the gamma parameters, which must be related to the degrees of freedom.

Overrides:

setParameters in class GammaDistribution

Parameters:

k - the shape parameter

b - the scale parameter

toString

public java.lang.String toString()

This method returns a string that gives the name of the distribution and the values of the parameters.

Overrides:

toString in class GammaDistribution

Returns:

a string giving the name of the distribution and the values of the parameters