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

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

All Implemented Interfaces:

Distribution

public class LogisticDistribution
extends ContinuousDistribution

The Logistic distribution.

References:

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

Since:

1.2

Version:

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

Constructor Summary

LogisticDistribution()
Default constructor.

LogisticDistribution(double m, double s)
Create a distribution with the given mean and scale parameters.

Method Summary

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

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

LogisticDistribution

public LogisticDistribution()

Default constructor. The mean is set to zero and the scale parameter is set to one.

LogisticDistribution

public LogisticDistribution(double m,
                            double s)

Create a distribution with the given mean and scale parameters.

Parameters:

m - the mean.

s - the scale parameter.

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.

getScale

public double getScale()

Access the scale parameter.

Returns:

the scale parameter.

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.

setScale

public void setScale(double s)

Modify the scale parameter.

Parameters:

s - The new scale parameter value.