Package org.apache.commons.math.stat.inference

Interface OneWayAnova

  • All Known Implementing Classes:
    OneWayAnovaImpl
    public interface OneWayAnova
    An interface for one-way ANOVA (analysis of variance).

    Tests for differences between two or more categories of univariate data (for example, the body mass index of accountants, lawyers, doctors and computer programmers). When two categories are given, this is equivalent to the TTest.

    Since:
    1.2
    Version:
    $Revision: 811786 $ $Date: 2009-09-06 11:36:08 +0200 (dim. 06 sept. 2009) $

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      double anovaFValue​(java.util.Collection<double[]> categoryData)
      Computes the ANOVA F-value for a collection of double[] arrays.
      double anovaPValue​(java.util.Collection<double[]> categoryData)
      Computes the ANOVA P-value for a collection of double[] arrays.
      boolean anovaTest​(java.util.Collection<double[]> categoryData, double alpha)
      Performs an ANOVA test, evaluating the null hypothesis that there is no difference among the means of the data categories.

    • Method Detail

      • anovaFValue

        double anovaFValue​(java.util.Collection<double[]> categoryData)
            throws java.lang.IllegalArgumentException,
                   MathException
        Computes the ANOVA F-value for a collection of double[] arrays.

        Preconditions:

        • The categoryData Collection must contain double[] arrays.
        • There must be at least two double[] arrays in the categoryData collection and each of these arrays must contain at least two values.

        Parameters:
        categoryData - Collection of double[] arrays each containing data for one category
        Returns:
        Fvalue
        Throws:
        java.lang.IllegalArgumentException - if the preconditions are not met
        MathException - if the statistic can not be computed do to a convergence or other numerical error.

      • anovaPValue

        double anovaPValue​(java.util.Collection<double[]> categoryData)
            throws java.lang.IllegalArgumentException,
                   MathException
        Computes the ANOVA P-value for a collection of double[] arrays.

        Preconditions:

        • The categoryData Collection must contain double[] arrays.
        • There must be at least two double[] arrays in the categoryData collection and each of these arrays must contain at least two values.

        Parameters:
        categoryData - Collection of double[] arrays each containing data for one category
        Returns:
        Pvalue
        Throws:
        java.lang.IllegalArgumentException - if the preconditions are not met
        MathException - if the statistic can not be computed do to a convergence or other numerical error.

      • anovaTest

        boolean anovaTest​(java.util.Collection<double[]> categoryData,
                  double alpha)
           throws java.lang.IllegalArgumentException,
                  MathException
        Performs an ANOVA test, evaluating the null hypothesis that there is no difference among the means of the data categories.

        Preconditions:

        • The categoryData Collection must contain double[] arrays.
        • There must be at least two double[] arrays in the categoryData collection and each of these arrays must contain at least two values.
        • alpha must be strictly greater than 0 and less than or equal to 0.5.

        Parameters:
        categoryData - Collection of double[] arrays each containing data for one category
        alpha - significance level of the test
        Returns:
        true if the null hypothesis can be rejected with confidence 1 - alpha
        Throws:
        java.lang.IllegalArgumentException - if the preconditions are not met
        MathException - if the statistic can not be computed do to a convergence or other numerical error.