javanpst.distributions.tests

Class WilcoxonRankSumDistribution

java.lang.Object

javanpst.distributions.tests.WilcoxonRankSumDistribution

public class WilcoxonRankSumDistribution
extends java.lang.Object

An implementation of the Wilcoxon Ranks-Sum distribution. Uses a Singleton pattern to ensure only an instance of the class is allowed.

Method Summary

Modifier and Type	Method and Description
double	computeLeftProbability(int n, int m, int R) Computes left tail probability of the Wilcoxon Ranks-Sum distribution.
double	computeRightProbability(int n, int m, int R) Computes right tail probability of the Wilcoxon Ranks-Sum distribution.
int	findCriticalValue(int n, int m, double alpha) Finds the maximum rank whose p-value associated is equal o less than alpha/2 This method is used for computing confidence interval boundaries
static WilcoxonRankSumDistribution	getInstance() Singleton pattern access to the distribution
static Incomplete3KeyTable	getTable() Gets the table of the distribution
double	inverseFindCriticalValue(int n, int m, int u) Finds the p-value associated to a rank, provided that it exists This method is used for computing exact confidence for confidence intervals

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static WilcoxonRankSumDistribution getInstance()

Singleton pattern access to the distribution

Returns:

the instance of the distribution

getTable

public static Incomplete3KeyTable getTable()

Gets the table of the distribution

Returns:

Reference to the table

computeLeftProbability

public double computeLeftProbability(int n,
                                     int m,
                                     int R)

Computes left tail probability of the Wilcoxon Ranks-Sum distribution.

Parameters:

n - n parameter

m - m parameter

R - rank associated

Returns:

p-value associated

computeRightProbability

public double computeRightProbability(int n,
                                      int m,
                                      int R)

Computes right tail probability of the Wilcoxon Ranks-Sum distribution.

Parameters:

n - n parameter

m - m parameter

R - rank associated

Returns:

p-value associated

findCriticalValue

public int findCriticalValue(int n,
                             int m,
                             double alpha)

Finds the maximum rank whose p-value associated is equal o less than alpha/2 This method is used for computing confidence interval boundaries

Parameters:

n - n parameter

m - m parameter

alpha - alpha confidence required

Returns:

rank found

inverseFindCriticalValue

public double inverseFindCriticalValue(int n,
                                       int m,
                                       int u)

Finds the p-value associated to a rank, provided that it exists This method is used for computing exact confidence for confidence intervals

Parameters:

n - n parameter

m - m parameter

u - rank selected

Returns:

confidence associated