edu.uah.math.distributions

Class BetaDistribution

java.lang.Object

edu.uah.math.distributions.Distribution

edu.uah.math.distributions.BetaDistribution

All Implemented Interfaces:

java.io.Serializable

public class BetaDistribution
extends Distribution
implements java.io.Serializable

This class is models the beta distribution with specified left and right parameters.

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

Constructors

Constructor and Description
BetaDistribution() This default constructor creates a beta distribution with left and right parameters equal to 1.
BetaDistribution(double a, double b) This general constructor creates a beta distribution with specified left and right parameters.

Method Summary

Methods

Modifier and Type	Method and Description
double	getCDF(double x) This method computes the cumulative distribution function.
double	getDensity(double x) This method computes the probability density function.
double	getLeft() This method gets the left paramter.
double	getMaxDensity() This method computes the maximum value of the density function.
double	getMean() This method compute the mean in terms of the parameters.
double	getMoment(double a, int n) This method returns the moment a specified order about a specified point.
double	getMoment(int n) This method returns the moment of a specified order.
double	getRight() This method gets the right parameter.
double	getVariance() This method computes the variance in terms of the parameters.
void	setLeft(double a) This method sets the left parameter.
void	setParameters(double a, double b) This method sets the parameters, computes the normalizing constant c, and specifies the default domain.
void	setRight(double b) This method sets the right parameter.
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.Distribution

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

Methods inherited from class java.lang.Object

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

Constructor Detail

BetaDistribution

public BetaDistribution(double a,
                double b)

This general constructor creates a beta distribution with specified left and right parameters.

Parameters:

a - the left parameter

b - the right parameter

BetaDistribution

public BetaDistribution()

This default constructor creates a beta distribution with left and right parameters equal to 1. This is the uniform distribution on (0, 1).

Method Detail

setParameters

public void setParameters(double a,
                 double b)

This method sets the parameters, computes the normalizing constant c, and specifies the default domain.

Parameters:

a - the left parameter

b - the right parameter

setLeft

public void setLeft(double a)

This method sets the left parameter.

Parameters:

a - the left parameter

setRight

public void setRight(double b)

This method sets the right parameter.

Parameters:

b - the right parameter

getLeft

public double getLeft()

This method gets the left paramter.

Returns:

the left parameter

getRight

public double getRight()

This method gets the right parameter.

Returns:

the right parameter

getDensity

public double getDensity(double x)

This method computes the probability density function.

Specified by:

getDensity in class Distribution

Parameters:

x - a number in the domain of the distribution

Returns:

the probability density at x

getMaxDensity

public double getMaxDensity()

This method computes the maximum value of the density function.

Overrides:

getMaxDensity in class Distribution

Returns:

the maximum value of the probability density function

getMean

public double getMean()

This method compute the mean in terms of the parameters.

Overrides:

getMean in class Distribution

Returns:

the mean

getVariance

public double getVariance()

This method computes the variance in terms of the parameters.

Overrides:

getVariance in class Distribution

Returns:

the variance

getMoment

public double getMoment(int n)

This method returns the moment of a specified order.

Overrides:

getMoment in class Distribution

Parameters:

n - the order

Returns:

the moment of order n about 0

getMoment

public double getMoment(double a,
               int n)

This method returns the moment a specified order about a specified point.

Overrides:

getMoment in class Distribution

Parameters:

a - the center

n - the order

Returns:

the moment of order n about a

getCDF

public double getCDF(double x)

This method computes the cumulative distribution function.

Overrides:

getCDF in class Distribution

Parameters:

x - a number in the domain of the distribution

Returns:

the cumulative probability at x

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 Distribution

Returns:

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