# SuanShu, a Java numerical and statistical library

## com.numericalmethod.suanshu.stats.test.rank Class VanDerWaerden

java.lang.Object
com.numericalmethod.suanshu.stats.test.HypothesisTest
com.numericalmethod.suanshu.stats.test.rank.VanDerWaerden


public class VanDerWaerdenextends HypothesisTest

The Van der Waerden test tests for the equality of all population distribution functions. It converts the ranks from a standard Kruskal-Wallis one-way analysis of variance to quantiles of the standard normal distribution. These are called normal scores and the test is computed from these normal scores.

Wikipedia: Van der Waerden test

Constructor Summary
VanDerWaerden(double[]... samples)
Perform the Van Der Waerden test to test for the equality of all population distribution functions.

Method Summary
 String getAlternativeHypothesis()
Get the description of the alternative hypothesis.
 String getNullHypothesis()
Get a description of the null hypothesis.
 double pValue()
Get the p-value for the test statistics.
 double statistics()
Get the test statistics.

Methods inherited from class com.numericalmethod.suanshu.stats.test.HypothesisTest
isNullRejected, nGroups, nObs, oneSidedPvalue

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

### VanDerWaerden

public VanDerWaerden(double[]... samples)
Perform the Van Der Waerden test to test for the equality of all population distribution functions.

Parameters:
samples - samples
Method Detail

### getNullHypothesis

public String getNullHypothesis()
Description copied from class: HypothesisTest
Get a description of the null hypothesis.

Specified by:
getNullHypothesis in class HypothesisTest
Returns:
the null hypothesis description
Wikipedia: Null hypothesis

### getAlternativeHypothesis

public String getAlternativeHypothesis()
Description copied from class: HypothesisTest
Get the description of the alternative hypothesis.

Specified by:
getAlternativeHypothesis in class HypothesisTest
Returns:
the alternative hypothesis description
Wikipedia: Alternative hypothesis

### statistics

public double statistics()
Description copied from class: HypothesisTest
Get the test statistics.

Specified by:
statistics in class HypothesisTest
Returns:
the test statistics
Wikipedia: Test statistic

### pValue

public double pValue()
Description copied from class: HypothesisTest
Get the p-value for the test statistics.

Specified by:
pValue in class HypothesisTest
Returns:
the p-value