org.statcato.statistics.inferential

Class GoodnessOfFitTest

java.lang.Object

org.statcato.statistics.inferential.GoodnessOfFitTest

public class GoodnessOfFitTest
extends java.lang.Object

A Chi-square goodness-of-fit test.

Since:

1.0

Constructor Summary

Constructors

Constructor and Description
GoodnessOfFitTest(int k, double confidence) Constructor.

Method Summary

Modifier and Type	Method and Description
double	criticalValue() Returns the critical value corresponding to the significance level and degrees of freedom.
int	DOF() Returns the degrees of freedom.
double	pValue(double ts) Returns the p-Value corresponding to the given test statistic in a chi-square distribution.
double	testStatistic(java.util.Vector<java.lang.Double> observedFreq, java.util.Vector<java.lang.Double> expectedFreq) Computes the chi-square test statistic for goodness-of-fit test in multinomial experiment, given the observed and expected frequencies.
java.util.Vector<java.lang.Double>	testStatisticContribution(java.util.Vector<java.lang.Double> observedFreq, java.util.Vector<java.lang.Double> expectedFreq) Returns a vector of each observed frequency's contribution to the chi-square test statistic.

Methods inherited from class java.lang.Object

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

Constructor Detail

GoodnessOfFitTest

public GoodnessOfFitTest(int k,
                         double confidence)

Constructor.

Parameters:

k - number of categories

confidence - confidence level

Method Detail

testStatisticContribution

public java.util.Vector<java.lang.Double> testStatisticContribution(java.util.Vector<java.lang.Double> observedFreq,
                                                                    java.util.Vector<java.lang.Double> expectedFreq)

Returns a vector of each observed frequency's contribution to the chi-square test statistic.

Parameters:

observedFreq - vector of observed frequencies

expectedFreq - vector of expected frequencies

Returns:

a vector of Double (each observed frequency's contribution to test statistic)

testStatistic

public double testStatistic(java.util.Vector<java.lang.Double> observedFreq,
                            java.util.Vector<java.lang.Double> expectedFreq)

Computes the chi-square test statistic for goodness-of-fit test in multinomial experiment, given the observed and expected frequencies. Chi^2 = Sum_{(O - E)^2 / E}.

Parameters:

observedFreq - a vector of observed frequencies

expectedFreq - a vector of expected frequencies

Returns:

test statistic

DOF

public int DOF()

Returns the degrees of freedom.

Returns:

degrees of freedom

criticalValue

public double criticalValue()

Returns the critical value corresponding to the significance level and degrees of freedom.

Returns:

critical value

pValue

public double pValue(double ts)

Returns the p-Value corresponding to the given test statistic in a chi-square distribution.

Parameters:

ts -

Returns:

p-value