com.numericalmethod.suanshu.stats.test.distribution.normality
Class ShapiroWilk

java.lang.Object
  com.numericalmethod.suanshu.stats.test.HypothesisTest
      com.numericalmethod.suanshu.stats.test.distribution.normality.ShapiroWilk

public class ShapiroWilk
extends HypothesisTest

The Shapiro–Wilk test tests the null hypothesis that a sample comes from a normally distributed population.

The sample size must be between 3 and 5000.

The R equivalent function is shapiro.test.

See Also:

• Wikipedia: Shapiro–Wilk test
• Patrick Royston. "A Remark on Algorithm AS 181: The W Test for Normality," Applied Statistics, 44, 547–551. 1995.
• Patrick Royston. "Approximating the Shapiro-Wilk W-test for non-normality," Statistics and Computing, Volume 2, Number 3, 117-119. 1992.
• Patrick Royston. "An Extension of Shapiro and Wilk's W Test for Normality to Large Samples," Applied Statistics, 31, 115–124. 1982d.
• Patrick Royston. "Algorithm AS 181: The W Test for Normality," Applied Statistics, 31, 176–180. 1982c.
• Patrick Royston. "An extension of Shapiro and Wilk's Wtest for normality to large samples," Appl. Statist., 31, 115-124. 1982b.
• Patrick Royston. "Algorithm AS177. Expected normal order statistics (exact and approximate)," Applied Statistics, 31, 161-165. 1982a.

Field Summary

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

k, N, pValue, testStatistics

Constructor Summary

ShapiroWilk(double[] sample)
Perform the Shapiro-Wilk test to test for the null hypothesis that a sample comes from a normally distributed population.

Method Summary

java.lang.String	alternativeHypothesis() Get a description of the alternative hypothesis.
java.lang.String	nullHypothesis() Get a description of the null hypothesis.

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

oneSidedPvalue, pValue, rejectNull, testStatistics

Methods inherited from class java.lang.Object

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

Constructor Detail

ShapiroWilk

public ShapiroWilk(double[] sample)

Perform the Shapiro-Wilk test to test for the null hypothesis that a sample comes from a normally distributed population.

Parameters:

sample - a sample

Method Detail

nullHypothesis

public java.lang.String nullHypothesis()

Description copied from class: HypothesisTest

Get a description of the null hypothesis.

Specified by:

nullHypothesis in class HypothesisTest

Returns:

the null hypothesis description

See Also:

Wikipedia: Null hypothesis

alternativeHypothesis

public java.lang.String alternativeHypothesis()

Description copied from class: HypothesisTest

Get a description of the alternative hypothesis.

Specified by:

alternativeHypothesis in class HypothesisTest

Returns:

the alternative hypothesis description

See Also:

Wikipedia: Alternative hypothesis