Package org.moeaframework.util.statistics

Class OneWayANOVA

java.lang.Object
org.moeaframework.util.statistics.IntervalRatioStatisticalTest
org.moeaframework.util.statistics.OneWayANOVA
All Implemented Interfaces:
StatisticalTest
public class OneWayANOVA extends IntervalRatioStatisticalTest
The Single-Factor Between-Subjects Analysis of Variance determines if (at least) two out of K >= 2 populations have differing means.
  • Null Hypothesis: All populations have equal means.
  • Alternative Hypothesis: Not all populations have equal means.

Assumptions:

  1. Samples are randomly selected from their corresponding populations
  2. The distribution of the underlying populations are normal
  3. The variances of the underlying populations are identical

References:

  1. Sheskin, D.J. "Handbook of Parametric and Nonparametric Statistical Procedures, Third Edition." Chapman & Hall/CRC. 2004.

  • Field Summary

    Fields inherited from class org.moeaframework.util.statistics.IntervalRatioStatisticalTest

    data, numberOfGroups

  • Constructor Summary

    Constructors
    Constructor
    Description
    OneWayANOVA(int numberOfGroups)
    Constructs a one-way ANOVA statistical test with the specified number of groups.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(double value, int group)
    Adds a new observation with the specified value and group.
    void
    addAll(double[] values, int group)
    Adds several new observations to the specified group.
    org.apache.commons.math3.stat.descriptive.DescriptiveStatistics
    getStatistics(int group)
    Returns the descriptive statistics for the given group.
    boolean
    test(double alpha)
    Returns true if the null hypothesis is rejected; false otherwise.

    Methods inherited from class org.moeaframework.util.statistics.IntervalRatioStatisticalTest

    categorize, getNumberOfGroups

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • OneWayANOVA

      public OneWayANOVA(int numberOfGroups)
      Constructs a one-way ANOVA statistical test with the specified number of groups.
      Parameters:
      numberOfGroups - the number of groups being tested

  • Method Details

    • add

      public void add(double value, int group)
      Description copied from class: IntervalRatioStatisticalTest
      Adds a new observation with the specified value and group.
      Overrides:
      add in class IntervalRatioStatisticalTest
      Parameters:
      value - the value of the new observation
      group - the group to which the new observation belongs

    • addAll

      public void addAll(double[] values, int group)
      Description copied from class: IntervalRatioStatisticalTest
      Adds several new observations to the specified group.
      Overrides:
      addAll in class IntervalRatioStatisticalTest
      Parameters:
      values - the values of the new observations
      group - the group to which the new observations belong

    • getStatistics

      public org.apache.commons.math3.stat.descriptive.DescriptiveStatistics getStatistics(int group)
      Description copied from class: IntervalRatioStatisticalTest
      Returns the descriptive statistics for the given group.
      Overrides:
      getStatistics in class IntervalRatioStatisticalTest
      Parameters:
      group - the group
      Returns:
      the descriptive statistics

    • test

      public boolean test(double alpha)
      Returns true if the null hypothesis is rejected; false otherwise. The meaning of the null hypothesis and alternative hypothesis depends on the specific test.

      The prespecified level of confidence, alpha, can be used for either one-tailed or two-tailed (directional or non-directional) distributions, depending on the specific test. Some tests may only support specific values for alpha.

      Parameters:
      alpha - the prespecified level of confidence
      Returns:
      true if the null hypothesis is rejected; false otherwise
      See Also:
      • TestUtils.oneWayAnovaTest(java.util.Collection, double)