gov.sandia.cognition.statistics.distribution

Class ChiSquareDistribution.PDF

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.AbstractClosedFormSmoothUnivariateDistribution

gov.sandia.cognition.statistics.distribution.ChiSquareDistribution

gov.sandia.cognition.statistics.distribution.ChiSquareDistribution.PDF

All Implemented Interfaces:

Evaluator<java.lang.Double,java.lang.Double>, Vectorizable, ScalarFunction<java.lang.Double>, UnivariateScalarFunction, ClosedFormComputableDistribution<java.lang.Double>, ClosedFormDistribution<java.lang.Double>, ClosedFormUnivariateDistribution<java.lang.Double>, ComputableDistribution<java.lang.Double>, Distribution<java.lang.Double>, DistributionWithMean<java.lang.Double>, ProbabilityDensityFunction<java.lang.Double>, ProbabilityFunction<java.lang.Double>, SmoothUnivariateDistribution, UnivariateDistribution<java.lang.Double>, UnivariateProbabilityDensityFunction, CloneableSerializable, java.io.Serializable, java.lang.Cloneable

Enclosing class:

ChiSquareDistribution

public static class ChiSquareDistribution.PDF
extends ChiSquareDistribution
implements UnivariateProbabilityDensityFunction

PDF of the Chi-Square distribution

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class gov.sandia.cognition.statistics.distribution.ChiSquareDistribution

ChiSquareDistribution.CDF, ChiSquareDistribution.PDF

Field Summary

Fields inherited from class gov.sandia.cognition.statistics.distribution.ChiSquareDistribution

DEFAULT_DEGREES_OF_FREEDOM

Constructor Summary

Constructors

Constructor and Description
PDF() Default constructor.
PDF(ChiSquareDistribution other) Copy constructor
PDF(double degreesOfFreedom) Creates a new instance of ChiSquareDistribution

Method Summary

Modifier and Type	Method and Description
double	evaluate(double input) Produces a double output for the given double input
java.lang.Double	evaluate(java.lang.Double input) Evaluates the function on the given input and returns the output.
static double	evaluate(double x, double degreesOfFreedom) Evaluates the chi-square PDF for the given input and DOFs
double	evaluateAsDouble(java.lang.Double input) Evaluates the scalar function as a double.
ChiSquareDistribution.PDF	getProbabilityFunction() Gets the distribution function associated with this Distribution, either the PDF or PMF.
double	logEvaluate(double input) Evaluate the natural logarithm of the distribution function.
double	logEvaluate(java.lang.Double input) Evaluate the natural logarithm of the distribution function.
static double	logEvaluate(double x, double degreesOfFreedom) Computes the natural logarithm of the PDF.

Methods inherited from class gov.sandia.cognition.statistics.distribution.ChiSquareDistribution

clone, convertFromVector, convertToVector, getCDF, getDegreesOfFreedom, getMaxSupport, getMeanAsDouble, getMinSupport, getVariance, sample, sampleAsDoubles, sampleInto, setDegreesOfFreedom

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

getMean, sampleAsDouble, sampleAsDoubles, sampleInto

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.SmoothUnivariateDistribution

getCDF, getMean, sampleAsDouble, sampleAsDoubles, sampleInto

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

getMaxSupport, getMeanAsDouble, getMinSupport, getVariance

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

sample, sample, sampleInto

Methods inherited from interface gov.sandia.cognition.math.matrix.Vectorizable

clone, convertFromVector, convertToVector

Constructor Detail

PDF

public PDF()

Default constructor.

PDF

public PDF(double degreesOfFreedom)

Creates a new instance of ChiSquareDistribution

Parameters:

degreesOfFreedom - Number of degrees of freedom in the distribution, must be greater than 0.0

PDF

public PDF(ChiSquareDistribution other)

Copy constructor

Parameters:

other - ChiSquareDistribution to copy

Method Detail

evaluate

public java.lang.Double evaluate(java.lang.Double input)

Description copied from interface: Evaluator

Evaluates the function on the given input and returns the output.

Specified by:

evaluate in interface Evaluator<java.lang.Double,java.lang.Double>

Specified by:

evaluate in interface ScalarFunction<java.lang.Double>

Specified by:

evaluate in interface UnivariateScalarFunction

Parameters:

input - The input to evaluate.

Returns:

The output produced by evaluating the input.

evaluateAsDouble

public double evaluateAsDouble(java.lang.Double input)

Description copied from interface: ScalarFunction

Evaluates the scalar function as a double.

Specified by:

evaluateAsDouble in interface ScalarFunction<java.lang.Double>

Specified by:

evaluateAsDouble in interface UnivariateScalarFunction

Parameters:

input - The input value.

Returns:

The scalar output calculated from the given input.

evaluate

public double evaluate(double input)

Description copied from interface: UnivariateScalarFunction

Produces a double output for the given double input

Specified by:

evaluate in interface UnivariateScalarFunction

Parameters:

input - Input to the Evaluator

Returns:

output at the given input

evaluate

public static double evaluate(double x,
                              double degreesOfFreedom)

Evaluates the chi-square PDF for the given input and DOFs

Parameters:

x - Input to the PDF

degreesOfFreedom - DOFs of the PDF

Returns:

p(x|dof)

logEvaluate

public double logEvaluate(java.lang.Double input)

Description copied from interface: ProbabilityFunction

Evaluate the natural logarithm of the distribution function. This is sometimes more efficient than evaluating the distribution function itself, and when evaluating the product of many independent or exchangeable samples.

Specified by:

logEvaluate in interface ProbabilityFunction<java.lang.Double>

Parameters:

input - The input to be evaluated

Returns:

Natural logarithm of the distribution function.

logEvaluate

public double logEvaluate(double input)

Description copied from interface: UnivariateProbabilityDensityFunction

Evaluate the natural logarithm of the distribution function. This is sometimes more efficient than evaluating the distribution function itself, and when evaluating the product of many independent or exchangeable samples.

Specified by:

logEvaluate in interface UnivariateProbabilityDensityFunction

Parameters:

input - The input value.

Returns:

The natural logarithm of the distribution function.

logEvaluate

public static double logEvaluate(double x,
                                 double degreesOfFreedom)

Computes the natural logarithm of the PDF.

Parameters:

x - Input to the PDF

degreesOfFreedom - DOFs of the PDF

Returns:

Natural logarithm of the PDF.

getProbabilityFunction

public ChiSquareDistribution.PDF getProbabilityFunction()

Description copied from interface: ComputableDistribution

Gets the distribution function associated with this Distribution, either the PDF or PMF.

Specified by:

getProbabilityFunction in interface ComputableDistribution<java.lang.Double>

Specified by:

getProbabilityFunction in interface ProbabilityDensityFunction<java.lang.Double>

Specified by:

getProbabilityFunction in interface SmoothUnivariateDistribution

Specified by:

getProbabilityFunction in interface UnivariateProbabilityDensityFunction

Overrides:

getProbabilityFunction in class ChiSquareDistribution

Returns:

Distribution function associated with this Distribution.