Class OneWayAnova.Result

java.lang.Object
org.apache.commons.statistics.inference.BaseSignificanceResult
org.apache.commons.statistics.inference.OneWayAnova.Result
All Implemented Interfaces:
SignificanceResult
Enclosing class:
OneWayAnova

public static final class OneWayAnova.Result extends BaseSignificanceResult
Result for the one-way ANOVA.

This class is immutable.

Since:
1.1
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private final int
    Degrees of freedom in numerator (between groups).
    private final long
    Degrees of freedom in denominator (within groups).
    private final double
    Mean square between groups.
    private final double
    Mean square within groups.
    private final double
    nO value used to partition the variance.
  • Constructor Summary

    Constructors
    Constructor
    Description
    Result(int dfbg, long dfwg, double msbg, double mswg, double nO, double f, double p)
     
  • Method Summary

    Modifier and Type
    Method
    Description
    (package private) int
    Gets the degrees of freedom in the numerator (between groups).
    (package private) long
    Gets the degrees of freedom in the denominator (within groups).
    double
    Gets the mean square between groups.
    double
    Gets the mean square within groups.
    double
    Gets the variance component between groups.
    double
    Gets the variance component within groups.

    Methods inherited from class org.apache.commons.statistics.inference.BaseSignificanceResult

    getPValue, getStatistic

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface org.apache.commons.statistics.inference.SignificanceResult

    reject
  • Field Details

    • dfbg

      private final int dfbg
      Degrees of freedom in numerator (between groups).
    • dfwg

      private final long dfwg
      Degrees of freedom in denominator (within groups).
    • msbg

      private final double msbg
      Mean square between groups.
    • mswg

      private final double mswg
      Mean square within groups.
    • nO

      private final double nO
      nO value used to partition the variance.
  • Constructor Details

    • Result

      Result(int dfbg, long dfwg, double msbg, double mswg, double nO, double f, double p)
      Parameters:
      dfbg - Degrees of freedom in numerator (between groups).
      dfwg - Degrees of freedom in denominator (within groups).
      msbg - Mean square between groups.
      mswg - Mean square within groups.
      nO - Factor for partitioning the variance.
      f - F statistic
      p - P-value.
  • Method Details

    • getDFBG

      int getDFBG()
      Gets the degrees of freedom in the numerator (between groups).
      Returns:
      degrees of freedom between groups
    • getDFWG

      long getDFWG()
      Gets the degrees of freedom in the denominator (within groups).
      Returns:
      degrees of freedom within groups
    • getMSBG

      public double getMSBG()
      Gets the mean square between groups.
      Returns:
      mean square between groups
    • getMSWG

      public double getMSWG()
      Gets the mean square within groups.
      Returns:
      mean square within groups
    • getVCBG

      public double getVCBG()
      Gets the variance component between groups.

      The value is a partitioning of the variance. It is the complement of getVCWG().

      Partitioning the variance applies only to a model II (random effects) one-way anova. This applies when the groups are random samples from a larger set of groups; partitioning the variance allows comparison of the variation between groups to the variation within groups.

      If the MSBG is less than the MSWG this returns 0. Otherwise this creates an estimate of the added variance component between groups as:

      \[ \text{between-group variance} = A = (\text{MS}_{\text{bg}} - \text{MS}_{\text{wg}}) / n_o \]

      where \( n_o \) is a number close to, but usually less than, the arithmetic mean of the sample size \(n_i\) of each of the \( a \) groups:

      \[ n_o = \frac{1}{a-1} \left( \sum_i{n_i} - \frac{\sum_i{n_i^2}}{\sum_i{n_i}} \right) \]

      The added variance component among groups \( A \) is expressed as a fraction of the total variance components \( A + B \) where \( B \) is the MSWG.

      Returns:
      variance component between groups (in [0, 1]).
    • getVCWG

      public double getVCWG()
      Gets the variance component within groups.

      The value is a partitioning of the variance. It is the complement of getVCBG(). See that method for details.

      Returns:
      variance component within groups (in [0, 1]).