Package dev.nm.stat.test.variance
Class Levene
- java.lang.Object
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- dev.nm.stat.test.HypothesisTest
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- dev.nm.stat.test.variance.Levene
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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. Some statistical tests, for example ANOVA, assume that variances are equal across groups or samples. A homoscedasticity test, such as the Levene test, can be used to verify that assumption. The R equivalent function islevene.test
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
Levene.Type
the available implementations when computing the absolute deviations
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Constructor Summary
Constructors Constructor Description Levene(double... samples)
Perform the Levene test to test for equal variances across the groups.Levene(Levene.Type type, double[]... samples)
Perform the Levene test to test for equal variances across the groups.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description 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 dev.nm.stat.test.HypothesisTest
isNullRejected, nGroups, nObs, oneSidedPvalue
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Constructor Detail
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Levene
public Levene(double... samples)
Perform the Levene test to test for equal variances across the groups. The absolute deviations are computed from the medians.- Parameters:
samples
- samples
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Levene
public Levene(Levene.Type type, double[]... samples)
Perform the Levene test to test for equal variances across the groups.- Parameters:
type
- the implementation chosensamples
- samples
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Method Detail
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getNullHypothesis
public String getNullHypothesis()
Description copied from class:HypothesisTest
Get a description of the null hypothesis.- Specified by:
getNullHypothesis
in classHypothesisTest
- Returns:
- the null hypothesis description
- See Also:
- Wikipedia: Null hypothesis
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getAlternativeHypothesis
public String getAlternativeHypothesis()
Description copied from class:HypothesisTest
Get the description of the alternative hypothesis.- Specified by:
getAlternativeHypothesis
in classHypothesisTest
- Returns:
- the alternative hypothesis description
- See Also:
- Wikipedia: Alternative hypothesis
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statistics
public double statistics()
Description copied from class:HypothesisTest
Get the test statistics.- Specified by:
statistics
in classHypothesisTest
- Returns:
- the test statistics
- See Also:
- Wikipedia: Test statistic
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pValue
public double pValue()
Description copied from class:HypothesisTest
Get the p-value for the test statistics.- Specified by:
pValue
in classHypothesisTest
- Returns:
- the p-value
- See Also:
- Wikipedia: P-value
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