org.apache.commons.math.distribution
Class ChiSquaredDistributionImpl

java.lang.Object
  extended byorg.apache.commons.math.distribution.AbstractContinuousDistribution
      extended byorg.apache.commons.math.distribution.ChiSquaredDistributionImpl
All Implemented Interfaces:
ChiSquaredDistribution, ContinuousDistribution, Serializable

public class ChiSquaredDistributionImpl
extends AbstractContinuousDistribution
implements ChiSquaredDistribution, Serializable

The default implementation of ChiSquaredDistribution

Version:
$Revision: 1.11 $ $Date: 2003/11/19 03:22:53 $
See Also:
Serialized Form

Constructor Summary
ChiSquaredDistributionImpl(double degreesOfFreedom)
          Create a Chi-Squared distribution with the given degrees of freedom.
 
Method Summary
 double cummulativeProbability(double x)
          For this disbution, X, this method returns P(X < x).
 double getDegreesOfFreedom()
          Access the degrees of freedom.
protected  double getDomainLowerBound(double p)
          Access the domain value lower bound, based on p, used to bracket a CDF root.
protected  double getDomainUpperBound(double p)
          Access the domain value upper bound, based on p, used to bracket a CDF root.
protected  double getInitialDomain(double p)
          Access the initial domain value, based on p, used to bracket a CDF root.
 void setDegreesOfFreedom(double degreesOfFreedom)
          Modify the degrees of freedom.
 
Methods inherited from class org.apache.commons.math.distribution.AbstractContinuousDistribution
cummulativeProbability, inverseCummulativeProbability
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.apache.commons.math.distribution.ContinuousDistribution
cummulativeProbability, inverseCummulativeProbability
 

Constructor Detail

ChiSquaredDistributionImpl

public ChiSquaredDistributionImpl(double degreesOfFreedom)
Create a Chi-Squared distribution with the given degrees of freedom.

Parameters:
degreesOfFreedom - degrees of freedom.
Method Detail

setDegreesOfFreedom

public void setDegreesOfFreedom(double degreesOfFreedom)
Modify the degrees of freedom.

Specified by:
setDegreesOfFreedom in interface ChiSquaredDistribution
Parameters:
degreesOfFreedom - the new degrees of freedom.

getDegreesOfFreedom

public double getDegreesOfFreedom()
Access the degrees of freedom.

Specified by:
getDegreesOfFreedom in interface ChiSquaredDistribution
Returns:
the degrees of freedom.

cummulativeProbability

public double cummulativeProbability(double x)
                              throws MathException
For this disbution, X, this method returns P(X < x).

Specified by:
cummulativeProbability in interface ContinuousDistribution
Parameters:
x - the value at which the CDF is evaluated.
Returns:
CDF for this distribution.
Throws:
MathException

getDomainLowerBound

protected double getDomainLowerBound(double p)
Access the domain value lower bound, based on p, used to bracket a CDF root. This method is used by AbstractContinuousDistribution.inverseCummulativeProbability(double) to find critical values.

Specified by:
getDomainLowerBound in class AbstractContinuousDistribution
Parameters:
p - the desired probability for the critical value
Returns:
domain value lower bound, i.e. P(X < lower bound) < p

getDomainUpperBound

protected double getDomainUpperBound(double p)
Access the domain value upper bound, based on p, used to bracket a CDF root. This method is used by AbstractContinuousDistribution.inverseCummulativeProbability(double) to find critical values.

Specified by:
getDomainUpperBound in class AbstractContinuousDistribution
Parameters:
p - the desired probability for the critical value
Returns:
domain value upper bound, i.e. P(X < upper bound) > p

getInitialDomain

protected double getInitialDomain(double p)
Access the initial domain value, based on p, used to bracket a CDF root. This method is used by AbstractContinuousDistribution.inverseCummulativeProbability(double) to find critical values.

Specified by:
getInitialDomain in class AbstractContinuousDistribution
Parameters:
p - the desired probability for the critical value
Returns:
initial domain value


Copyright © 2003-2004 Apache Software Foundation. All Rights Reserved.