edu.uah.math.distributions
Class ExponentialDistribution

java.lang.Object
  edu.uah.math.distributions.Distribution
      edu.uah.math.distributions.GammaDistribution
          edu.uah.math.distributions.ExponentialDistribution

All Implemented Interfaces:

java.io.Serializable

public class ExponentialDistribution
extends GammaDistribution
implements java.io.Serializable

This class defines the standard exponential distribution with a specified rate 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

ExponentialDistribution()
This default constructor creates a new exponential distribution with rate 1.

ExponentialDistribution(double r)
This general constructor creates a new exponential distribution with a specified rate.

Method Summary

double	getCDF(double x) This method defines the cumulative distribution function.
double	getDensity(double x) This method computes the probability denstiy function.
double	getMoment(int n) This method computes the moment of order n.
double	getQuantile(double p) The method computes the quantile function.
double	getRate() This method gets the rate.
void	setParameters(double k, double b) This method sets the gamma shape and scale parameters.
void	setRate(double r) This method sets the rate parameter.
void	setShape(double k) This method sets the gamma shape parameter, which must be 1.
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.GammaDistribution

getMaxDensity, getMean, getMGF, getMoment, getScale, getShape, getVariance, setScale, simulate

Methods inherited from class edu.uah.math.distributions.Distribution

getDomain, getFailureRate, getMedian, getPGF, getSD, getType, setDomain, setDomain

Methods inherited from class java.lang.Object

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

Constructor Detail

ExponentialDistribution

public ExponentialDistribution(double r)

This general constructor creates a new exponential distribution with a specified rate.

Parameters:

r - the rate

ExponentialDistribution

public ExponentialDistribution()

This default constructor creates a new exponential distribution with rate 1.

Method Detail

setRate

public void setRate(double r)

This method sets the rate parameter.

Parameters:

r - the rate

getRate

public double getRate()

This method gets the rate.

Returns:

the rate

getDensity

public double getDensity(double x)

This method computes the probability denstiy function.

Overrides:

getDensity in class GammaDistribution

Parameters:

x - a number in the domain of the distribution

Returns:

the probability density at x

getCDF

public double getCDF(double x)

This method defines the cumulative distribution function.

Overrides:

getCDF in class GammaDistribution

Parameters:

x - a number in the domain of the distribution

Returns:

the cumulative probability at x

getQuantile

public double getQuantile(double p)

The method computes the quantile function.

Overrides:

getQuantile in class Distribution

Parameters:

p - a probability in (0, 1)

Returns:

the quantile of order p

getMoment

public double getMoment(int n)

This method computes the moment of order n.

Overrides:

getMoment in class GammaDistribution

Parameters:

n - the order

Returns:

the moment of order n

setShape

public void setShape(double k)

This method sets the gamma shape parameter, which must be 1.

Overrides:

setShape in class GammaDistribution

Parameters:

k - the shape parameter

setParameters

public void setParameters(double k,
                          double b)

This method sets the gamma shape and scale parameters. The shape parameter must be 1.

Overrides:

setParameters in class GammaDistribution

Parameters:

k - the shape parameter

b - the scale parameter

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 GammaDistribution

Returns:

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