org.apache.commons.math.distribution
Class HypergeometricDistributionImpl

java.lang.Object
  org.apache.commons.math.distribution.AbstractDistribution
      org.apache.commons.math.distribution.AbstractIntegerDistribution
          org.apache.commons.math.distribution.HypergeometricDistributionImpl

All Implemented Interfaces:

DiscreteDistribution, Distribution, HypergeometricDistribution, IntegerDistribution, Serializable

public class HypergeometricDistributionImpl

extends AbstractIntegerDistribution

implements HypergeometricDistribution, Serializable

The default implementation of HypergeometricDistribution.

Version:

$Revision: 1.16 $ $Date: 2004/11/07 03:32:48 $

See Also:

Serialized Form

Field Summary

(package private) static long

serialVersionUID Serializable version identifier

Constructor Summary

HypergeometricDistributionImpl(int populationSize, int numberOfSuccesses, int sampleSize)
Construct a new hypergeometric distribution with the given the population size, the number of successes in the population, and the sample size.

Method Summary

double	cumulativeProbability(int x) For this disbution, X, this method returns P(X ≤ x).
protected int	getDomainLowerBound(double p) Access the domain value lower bound, based on p, used to bracket a PDF root.
protected int	getDomainUpperBound(double p) Access the domain value upper bound, based on p, used to bracket a PDF root.
int	getNumberOfSuccesses() Access the number of successes.
int	getPopulationSize() Access the population size.
int	getSampleSize() Access the sample size.
double	probability(int x) For this disbution, X, this method returns P(X = x).
void	setNumberOfSuccesses(int num) Modify the number of successes.
void	setPopulationSize(int size) Modify the population size.
void	setSampleSize(int size) Modify the sample size.

Methods inherited from class org.apache.commons.math.distribution.AbstractIntegerDistribution

cumulativeProbability, cumulativeProbability, inverseCumulativeProbability, probability

Methods inherited from class org.apache.commons.math.distribution.AbstractDistribution

cumulativeProbability

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.IntegerDistribution

cumulativeProbability, inverseCumulativeProbability

Methods inherited from interface org.apache.commons.math.distribution.DiscreteDistribution

probability

Methods inherited from interface org.apache.commons.math.distribution.Distribution

cumulativeProbability, cumulativeProbability

Field Detail

serialVersionUID

static final long serialVersionUID

Serializable version identifier

See Also:

Constant Field Values

Constructor Detail

HypergeometricDistributionImpl

public HypergeometricDistributionImpl(int populationSize,
                                      int numberOfSuccesses,
                                      int sampleSize)

Construct a new hypergeometric distribution with the given the population size, the number of successes in the population, and the sample size.

Parameters:

populationSize - the population size.

numberOfSuccesses - number of successes in the population.

sampleSize - the sample size.

Method Detail

cumulativeProbability

public double cumulativeProbability(int x)
                             throws MathException

For this disbution, X, this method returns P(X ≤ x).

Specified by:

cumulativeProbability in interface IntegerDistribution

Specified by:

cumulativeProbability in class AbstractIntegerDistribution

Parameters:

x - the value at which the PDF is evaluated.

Returns:

PDF for this distribution.

Throws:

MathException - if the cumulative probability can not be computed due to convergence or other numerical errors.

getDomainLowerBound

protected int getDomainLowerBound(double p)

Access the domain value lower bound, based on p, used to bracket a PDF root.

Specified by:

getDomainLowerBound in class AbstractIntegerDistribution

Parameters:

p - the desired probability for the critical value

Returns:

domain value lower bound, i.e. P(X < lower bound) < p

getDomainUpperBound

protected int getDomainUpperBound(double p)

Access the domain value upper bound, based on p, used to bracket a PDF root.

Specified by:

getDomainUpperBound in class AbstractIntegerDistribution

Parameters:

p - the desired probability for the critical value

Returns:

domain value upper bound, i.e. P(X < upper bound) > p

getNumberOfSuccesses

public int getNumberOfSuccesses()

Access the number of successes.

Specified by:

getNumberOfSuccesses in interface HypergeometricDistribution

Returns:

the number of successes.

getPopulationSize

public int getPopulationSize()

Access the population size.

Specified by:

getPopulationSize in interface HypergeometricDistribution

Returns:

the population size.

getSampleSize

public int getSampleSize()

Access the sample size.

Specified by:

getSampleSize in interface HypergeometricDistribution

Returns:

the sample size.

probability

public double probability(int x)

For this disbution, X, this method returns P(X = x).

Specified by:

probability in interface IntegerDistribution

Parameters:

x - the value at which the PMF is evaluated.

Returns:

PMF for this distribution.

setNumberOfSuccesses

public void setNumberOfSuccesses(int num)

Modify the number of successes.

Specified by:

setNumberOfSuccesses in interface HypergeometricDistribution

Parameters:

num - the new number of successes.

Throws:

IllegalArgumentException - if num is negative.

setPopulationSize

public void setPopulationSize(int size)

Modify the population size.

Specified by:

setPopulationSize in interface HypergeometricDistribution

Parameters:

size - the new population size.

Throws:

IllegalArgumentException - if size is not positive.

setSampleSize

public void setSampleSize(int size)

Modify the sample size.

Specified by:

setSampleSize in interface HypergeometricDistribution

Parameters:

size - the new sample size.

Throws:

IllegalArgumentException - if size is negative.