net.sf.doodleproject.numerics4j.statistics.distribution
Class ExponentialDistribution

java.lang.Object
  net.sf.doodleproject.numerics4j.statistics.distribution.ContinuousDistribution
      net.sf.doodleproject.numerics4j.statistics.distribution.ExponentialDistribution

All Implemented Interfaces:

Distribution

public class ExponentialDistribution
extends ContinuousDistribution

The Exponential distribution (1).

References:

1. Eric W. Weisstein. "Exponential Distribution." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/ExponentialDistribution.html

Version:

$Revision: 1.2 $ $Date: 2007/10/25 04:44:10 $

Constructor Summary

ExponentialDistribution()
Default constructor.

ExponentialDistribution(double m)
Create a distribution with the given mean.

Method Summary

double	cumulativeProbability(double x) The CDF for this distribution.
double	getMean() Access the mean.
double	inverseCumulativeProbability(double p) The inverse CDF for this distribution.
void	setMean(double m) Modify the mean.

Methods inherited from class net.sf.doodleproject.numerics4j.statistics.distribution.ContinuousDistribution

findInverseCumulativeProbability

Methods inherited from class java.lang.Object

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

Constructor Detail

ExponentialDistribution

public ExponentialDistribution()

Default constructor. Mean is set to 1.

ExponentialDistribution

public ExponentialDistribution(double m)

Create a distribution with the given mean.

Parameters:

m - the mean.

Method Detail

cumulativeProbability

public double cumulativeProbability(double x)

The CDF for this distribution. This method returns P(X < x).

Specified by:

cumulativeProbability in class ContinuousDistribution

Parameters:

x - the value at which the CDF is evaluated.

Returns:

CDF for this distribution.

getMean

public double getMean()

Access the mean.

Returns:

the mean.

inverseCumulativeProbability

public double inverseCumulativeProbability(double p)

The inverse CDF for this distribution. This method returns x such that, P(X < x) = p.

Specified by:

inverseCumulativeProbability in class ContinuousDistribution

Parameters:

p - the cumulative probability.

Returns:

x

setMean

public void setMean(double m)

Modify the mean.

Parameters:

m - The new mean value.