repicea.stats.distributions

Class ChiSquaredDistribution

java.lang.Object

repicea.stats.distributions.ChiSquaredDistribution

All Implemented Interfaces:

java.io.Serializable, CentralMomentsGettable, Distribution

public final class ChiSquaredDistribution
extends java.lang.Object
implements Distribution

The ChiSquareDistribution class represents a univariate Chi Square distribution with a given degrees of freedom.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface repicea.stats.Distribution

Distribution.Type

Constructor Summary

Constructors

Constructor and Description
ChiSquaredDistribution(int degreesOfFreedom, double meanValue) Constructor for univariate Chi-squared distribution.
ChiSquaredDistribution(int degreesOfFreedom, Matrix meanValues) Constructor for multivariate Chi-squared distribution (Wishart distribution).

Method Summary

Modifier and Type	Method and Description
int	getDegreesOfFreedom() This method returns the degrees of freedom.
Matrix	getMean() This method returns the first central moment, i.e.
Matrix	getRandomRealization() This method draws a random realization from the distribution.
Distribution.Type	getType() This method returns the type of the distribution.
Matrix	getVariance() This method returns the second central moment, i.e.
boolean	isMultivariate() This method returns true if the GaussianFunction instance is multivariate.
boolean	isParametric() This method returns true if the distribution is parametric or false otherwise.

Methods inherited from class java.lang.Object

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

Methods inherited from interface repicea.stats.Distribution

isUnivariate

Constructor Detail

ChiSquaredDistribution

public ChiSquaredDistribution(int degreesOfFreedom,
                              double meanValue)

Constructor for univariate Chi-squared distribution.

Parameters:

degreesOfFreedom - the degrees of freedom

meanValue - the mean value

ChiSquaredDistribution

public ChiSquaredDistribution(int degreesOfFreedom,
                              Matrix meanValues)

Constructor for multivariate Chi-squared distribution (Wishart distribution).

Parameters:

degreesOfFreedom - the degrees of freedom

meanValues - the mean value

Method Detail

getDegreesOfFreedom

public int getDegreesOfFreedom()

This method returns the degrees of freedom.

Returns:

an integer

getMean

public Matrix getMean()

Description copied from interface: CentralMomentsGettable

This method returns the first central moment, i.e. the mean vector, of the random variable.

Specified by:

getMean in interface CentralMomentsGettable

Returns:

a Matrix instance

getVariance

public Matrix getVariance()

Description copied from interface: CentralMomentsGettable

This method returns the second central moment, i.e. the variance-covariance matrix, of the random variable.

Specified by:

getVariance in interface CentralMomentsGettable

Returns:

a Number instance

isParametric

public boolean isParametric()

Description copied from interface: Distribution

This method returns true if the distribution is parametric or false otherwise.

Specified by:

isParametric in interface Distribution

Returns:

a boolean

isMultivariate

public boolean isMultivariate()

Description copied from interface: Distribution

This method returns true if the GaussianFunction instance is multivariate.

Specified by:

isMultivariate in interface Distribution

Returns:

a boolean

getType

public Distribution.Type getType()

Description copied from interface: Distribution

This method returns the type of the distribution.

Specified by:

getType in interface Distribution

Returns:

a Type enum

getRandomRealization

public Matrix getRandomRealization()

Description copied from interface: Distribution

This method draws a random realization from the distribution.

Specified by:

getRandomRealization in interface Distribution

Returns:

the observation in a Matrix instance