com.numericalmethod.suanshu.stats.test.distribution.pearson

Class FisherExactDistribution

java.lang.Object

com.numericalmethod.suanshu.stats.distribution.univariate.EmpiricalDistribution

com.numericalmethod.suanshu.stats.test.distribution.pearson.FisherExactDistribution

All Implemented Interfaces:

ProbabilityDistribution, java.io.Serializable

public class FisherExactDistribution
extends EmpiricalDistribution

Fisher's exact test is a statistical significance test used in the analysis of contingency tables where nextSample sizes are small. It converges to Chi-square distribution for a large and well balanced nextSample.

For small, sparse, or unbalanced data, the exact and asymptotic p-values can be quite different and may lead to opposite conclusions concerning the hypothesis of interest. In contrast the Fisher exact test is, as its name states, exact, and it can therefore be used regardless of the nextSample characteristics.

It becomes difficult to calculate with large samples or well-balanced tables, but fortunately these are exactly the conditions where the chi-square distribution is appropriate.

See Also:

Wikipedia: Fisher's exact test, Serialized Form

Constructor Summary

Constructors

Constructor and Description
FisherExactDistribution(int[] rowSums, int[] colSums, int nSim) Construct the distribution for the Fisher's exact test.
FisherExactDistribution(int[] rowSums, int[] colSums, int nSim, RandomLongGenerator rng) Construct the distribution for the Fisher's exact test.

Method Summary

Methods inherited from class com.numericalmethod.suanshu.stats.distribution.univariate.EmpiricalDistribution

cdf, density, entropy, kurtosis, mean, median, moment, nSamples, quantile, skew, toArray, variance

Methods inherited from class java.lang.Object

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

Constructor Detail

FisherExactDistribution

public FisherExactDistribution(int[] rowSums,
                               int[] colSums,
                               int nSim,
                               RandomLongGenerator rng)

Construct the distribution for the Fisher's exact test.

Parameters:

rowSums - row totals

colSums - column totals

nSim - number of simulations

rng - a uniform random number generator

FisherExactDistribution

public FisherExactDistribution(int[] rowSums,
                               int[] colSums,
                               int nSim)

Construct the distribution for the Fisher's exact test.

Parameters:

rowSums - row totals

colSums - column totals

nSim - number of simulations