com.numericalmethod.suanshu.stats.test.variance

Class Levene

java.lang.Object

com.numericalmethod.suanshu.stats.test.HypothesisTest

com.numericalmethod.suanshu.stats.test.variance.Levene

All Implemented Interfaces:

java.io.Serializable

public class Levene
extends HypothesisTest

The Levene test tests for the equality of variance of groups. Levene's test does not require normality of the underlying data.

The R equivalent function is levene.test.

See Also:

• Wikipedia: Levene's test
• Levene Test for Equality of Variances

, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Levene.Type the implementations available when computing the absolute deviations

Field Summary

Fields

Modifier and Type	Field and Description
double	df1 the degree of freedoms
double	df2 the degree of freedoms

Fields inherited from class com.numericalmethod.suanshu.stats.test.HypothesisTest

k, N, pValue, testStatistics

Constructor Summary

Constructors

Constructor and Description
Levene(double... samples) Perform the Levene test to test for homeogeneity of variance across groups.
Levene(Levene.Type type, double[]... samples) Perform the Levene test to test for homeogeneity of variance across groups.

Method Summary

Modifier and Type	Method and Description
java.lang.String	getAlternativeHypothesis() Get a description of the alternative hypothesis.
java.lang.String	getNullHypothesis() Get a description of the null hypothesis.

Methods inherited from class com.numericalmethod.suanshu.stats.test.HypothesisTest

isNullRejected, oneSidedPvalue, pValue, statistics

Methods inherited from class java.lang.Object

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

Field Detail

df1

public final double df1

the degree of freedoms

df2

public final double df2

the degree of freedoms

Constructor Detail

Levene

public Levene(double... samples)

Perform the Levene test to test for homeogeneity of variance across groups.

The absolute deviations are computed from the medians.

Parameters:

samples - samples

Levene

public Levene(Levene.Type type,
              double[]... samples)

Perform the Levene test to test for homeogeneity of variance across groups.

Parameters:

type - the implementation chosen

samples - samples

Method Detail

getNullHypothesis

public java.lang.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

See Also:

Wikipedia: Null hypothesis

getAlternativeHypothesis

public java.lang.String getAlternativeHypothesis()

Description copied from class: HypothesisTest

Get a description of the alternative hypothesis.

Specified by:

getAlternativeHypothesis in class HypothesisTest

Returns:

the alternative hypothesis description

See Also:

Wikipedia: Alternative hypothesis