edu.uah.math.distributions
Class StudentDistribution

java.lang.Object
  edu.uah.math.distributions.Distribution
      edu.uah.math.distributions.StudentDistribution

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

CauchyDistribution

public class StudentDistribution
extends Distribution
implements java.io.Serializable

This class models the student t distribution with a specifed degrees of freeom 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

StudentDistribution()
This default constructor creates a new student distribuion with 1 degree of freedom.

StudentDistribution(int n)
This general constructor creates a new student distribution with a specified degrees of freedom.

Method Summary

double	getCDF(double x) This method computes the cumulative distribution function in terms of the beta CDF.
double	getDegrees() This method returns the degrees of freedom parameter.
double	getDensity(double x) This method computes the probability density function.
double	getMaxDensity() This method returns the maximum value of the probability density function.
double	getMean() This method returns the mean of the distribution.
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 order n about 0.
double	getVariance() This method returns the variance of the distribution.
void	setDegrees(int n) This method sets the degrees of freedom.
double	simulate() This method simulates a value of the 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.Distribution

getDomain, getFailureRate, getMedian, getMGF, 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

StudentDistribution

public StudentDistribution(int n)

This general constructor creates a new student distribution with a specified degrees of freedom.

Parameters:

n - the degrees of freedom

StudentDistribution

public StudentDistribution()

This default constructor creates a new student distribuion with 1 degree of freedom.

Method Detail

setDegrees

public void setDegrees(int n)

This method sets the degrees of freedom.

Parameters:

n - the degrees of freedom

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 returns the maximum value of the probability density function.

Overrides:

getMaxDensity in class Distribution

Returns:

the maximum value of the probability denstiy function

getMean

public double getMean()

This method returns the mean of the distribution.

Overrides:

getMean in class Distribution

Returns:

the mean

getVariance

public double getVariance()

This method returns the variance of the distribution.

Overrides:

getVariance in class Distribution

Returns:

the variance

getMoment

public double getMoment(int n)

This method returns the moment of order n about 0.

Overrides:

getMoment in class Distribution

Parameters:

n - the order

Returns:

the moment of order n

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 in terms of the beta CDF.

Overrides:

getCDF in class Distribution

Parameters:

x - a number in the domain of the distribution

Returns:

the cumulative distribution at x

See Also:

betaCDF

getDegrees

public double getDegrees()

This method returns the degrees of freedom parameter.

Returns:

the degrees of freedom

simulate

public double simulate()

This method simulates a value of the distribution.

Overrides:

simulate in class Distribution

Returns:

a simulated value from the distribution

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