gov.sandia.cognition.statistics.distribution

Class SnedecorFDistribution

java.lang.Object

gov.sandia.cognition.util.AbstractCloneableSerializable

gov.sandia.cognition.statistics.AbstractDistribution<NumberType>

gov.sandia.cognition.statistics.AbstractClosedFormUnivariateDistribution<java.lang.Double>

gov.sandia.cognition.statistics.distribution.SnedecorFDistribution

All Implemented Interfaces:

Vectorizable, ClosedFormDistribution<java.lang.Double>, ClosedFormUnivariateDistribution<java.lang.Double>, Distribution<java.lang.Double>, DistributionWithMean<java.lang.Double>, UnivariateDistribution<java.lang.Double>, CloneableSerializable, java.io.Serializable, java.lang.Cloneable

Direct Known Subclasses:

SnedecorFDistribution.CDF

@PublicationReference(author="Wikipedia",
                      title="F-distribution",
                      type=WebPage,
                      year=2009,
                      url="http://en.wikipedia.org/wiki/F-distribution")
public class SnedecorFDistribution
extends AbstractClosedFormUnivariateDistribution<java.lang.Double>

CDF of the Snedecor F-distribution (also known as Fisher F-distribution, Fisher-Snedecor F-distribution, or just plain old F-distribution). This is a type of Beta Distribution, where F(x,v1,v2) = 1-Beta(v2/(v2+v1*x),v2,v1)

Since:

2.0

Author:

Kevin R. Dixon

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SnedecorFDistribution.CDF CDF of the F-distribution.

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_V1 Default value of v1, 3.0.
static double	DEFAULT_V2 Default value of v2, 5.0.

Constructor Summary

Constructors

Constructor and Description
SnedecorFDistribution() Default constructor
SnedecorFDistribution(double v1, double v2) Creates a new instance of CumulativeDistribution
SnedecorFDistribution(SnedecorFDistribution other) Copy Constructor

Method Summary

Modifier and Type	Method and Description
SnedecorFDistribution	clone() This makes public the clone method on the Object class and removes the exception that it throws.
void	convertFromVector(Vector parameters) Converts the object from a Vector of parameters.
Vector	convertToVector() Converts the object to a vector.
SnedecorFDistribution.CDF	getCDF() Gets the CDF of a scalar distribution.
java.lang.Double	getMaxSupport() Gets the minimum support (domain or input) of the distribution.
java.lang.Double	getMean() Gets the arithmetic mean, or "first central moment" or "expectation", of the distribution.
double	getMeanAsDouble() Gets the mean of the distribution as a double.
java.lang.Double	getMinSupport() Gets the minimum support (domain or input) of the distribution.
double	getV1() Getter for v1
double	getV2() Getter for v2
double	getVariance() Gets the variance of the distribution.
void	sampleInto(java.util.Random random, int sampleCount, java.util.Collection<? super java.lang.Double> output) Draws multiple random samples from the distribution and puts the result into the given collection.
void	setV1(double v1) Setter for v1
void	setV2(double v2) Setter for v2

Methods inherited from class gov.sandia.cognition.statistics.AbstractDistribution

sample, sample

Methods inherited from class java.lang.Object

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

Methods inherited from interface gov.sandia.cognition.statistics.Distribution

sample, sample

Field Detail

DEFAULT_V1

public static final double DEFAULT_V1

Default value of v1, 3.0.

See Also:

Constant Field Values

DEFAULT_V2

public static final double DEFAULT_V2

Default value of v2, 5.0.

See Also:

Constant Field Values

Constructor Detail

SnedecorFDistribution

public SnedecorFDistribution()

Default constructor

SnedecorFDistribution

public SnedecorFDistribution(double v1,
                             double v2)

Creates a new instance of CumulativeDistribution

Parameters:

v1 - First degree of freedom

v2 - Second degree of freedom

SnedecorFDistribution

public SnedecorFDistribution(SnedecorFDistribution other)

Copy Constructor

Parameters:

other - CumulativeDistribution to copy

Method Detail

clone

public SnedecorFDistribution clone()

Description copied from class: AbstractCloneableSerializable

This makes public the clone method on the Object class and removes the exception that it throws. Its default behavior is to automatically create a clone of the exact type of object that the clone is called on and to copy all primitives but to keep all references, which means it is a shallow copy. Extensions of this class may want to override this method (but call super.clone() to implement a "smart copy". That is, to target the most common use case for creating a copy of the object. Because of the default behavior being a shallow copy, extending classes only need to handle fields that need to have a deeper copy (or those that need to be reset). Some of the methods in ObjectUtil may be helpful in implementing a custom clone method. Note: The contract of this method is that you must use super.clone() as the basis for your implementation.

Specified by:

clone in interface Vectorizable

Specified by:

clone in interface CloneableSerializable

Overrides:

clone in class AbstractClosedFormUnivariateDistribution<java.lang.Double>

Returns:

A clone of this object.

getV1

public double getV1()

Getter for v1

Returns:

First degree of freedom

setV1

public void setV1(double v1)

Setter for v1

Parameters:

v1 - First degree of freedom

getV2

public double getV2()

Getter for v2

Returns:

Second degree of freedom

setV2

public void setV2(double v2)

Setter for v2

Parameters:

v2 - Second degree of freedom

getMean

public java.lang.Double getMean()

Description copied from interface: DistributionWithMean

Gets the arithmetic mean, or "first central moment" or "expectation", of the distribution.

Returns:

Mean of the distribution.

getMeanAsDouble

public double getMeanAsDouble()

Description copied from interface: UnivariateDistribution

Gets the mean of the distribution as a double.

Returns:

The mean as a double.

getVariance

public double getVariance()

Description copied from interface: UnivariateDistribution

Gets the variance of the distribution. This is sometimes called the second central moment by more pedantic people, which is equivalent to the square of the standard deviation.

Returns:

Variance of the distribution.

convertToVector

public Vector convertToVector()

Description copied from interface: Vectorizable

Converts the object to a vector.

Returns:

The Vector form of the object.

convertFromVector

public void convertFromVector(Vector parameters)

Description copied from interface: Vectorizable

Converts the object from a Vector of parameters.

Parameters:

parameters - The parameters to incorporate.

sampleInto

public void sampleInto(java.util.Random random,
                       int sampleCount,
                       java.util.Collection<? super java.lang.Double> output)

Description copied from interface: Distribution

Draws multiple random samples from the distribution and puts the result into the given collection.

Parameters:

random - Random number generator to use.

sampleCount - The number of samples to draw. Cannot be negative.

output - The collection to add the samples into.

getCDF

public SnedecorFDistribution.CDF getCDF()

Description copied from interface: UnivariateDistribution

Gets the CDF of a scalar distribution.

Returns:

CDF of the scalar distribution.

getMinSupport

public java.lang.Double getMinSupport()

Description copied from interface: UnivariateDistribution

Gets the minimum support (domain or input) of the distribution.

Returns:

Minimum support.

getMaxSupport

public java.lang.Double getMaxSupport()

Description copied from interface: UnivariateDistribution

Gets the minimum support (domain or input) of the distribution.

Returns:

Minimum support.