weka.experiment

## Class PairedStats

- java.lang.Object
- - weka.experiment.PairedStats

- All Implemented Interfaces:
    RevisionHandler
  Direct Known Subclasses:
    PairedStatsCorrected

      public class PairedStats
      extends java.lang.Object
      implements RevisionHandler

  A class for storing stats on a paired comparison (t-test and correlation)
  Version:
    $Revision: 8034 $
  Author:
    Len Trigg (trigg@cs.waikato.ac.nz)

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `double` | `correlation` The correlation coefficient
    `double` | `count` The number of data points seen
    `double` | `differencesProbability` The probability of obtaining the observed differences
    `int` | `differencesSignificance` A significance indicator: 0 if the differences are not significant > 0 if x significantly greater than y < 0 if x significantly less than y
    `Stats` | `differencesStats` The stats associated with the paired differences
    `double` | `sigLevel` The significance level for comparisons
    `Stats` | `xStats` The stats associated with the data in column 1
    `double` | `xySum` The sum of the products
    `Stats` | `yStats` The stats associated with the data in column 2

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `PairedStats(double sig)` Creates a new PairedStats object with the supplied significance level.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `add(double[] value1, double[] value2)` Adds an array of observed pair of values.
    `void` | `add(double value1, double value2)` Add an observed pair of values.
    `void` | `calculateDerived()` Calculates the derived statistics (significance etc).
    `int` | `getDegreesOfFreedom()` Gets the degrees of freedom.
    `java.lang.String` | `getRevision()` Returns the revision string.
    `static void` | `main(java.lang.String[] args)` Tests the paired stats object from the command line.
    `void` | `setDegreesOfFreedom(int d)` Sets the degrees of freedom (if calibration is required).
    `void` | `subtract(double[] value1, double[] value2)` Removes an array of observed pair of values.
    `void` | `subtract(double value1, double value2)` Removes an observed pair of values.
    `java.lang.String` | `toString()` Returns statistics on the paired comparison.

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### xStats

          public Stats xStats

      The stats associated with the data in column 1

    - #### yStats

          public Stats yStats

      The stats associated with the data in column 2

    - #### differencesStats

          public Stats differencesStats

      The stats associated with the paired differences

    - #### differencesProbability

          public double differencesProbability

      The probability of obtaining the observed differences

    - #### correlation

          public double correlation

      The correlation coefficient

    - #### xySum

          public double xySum

      The sum of the products

    - #### count

          public double count

      The number of data points seen

    - #### differencesSignificance

          public int differencesSignificance

      A significance indicator: 0 if the differences are not significant > 0 if x significantly greater than y < 0 if x significantly less than y

    - #### sigLevel

          public double sigLevel

      The significance level for comparisons

  - ### Constructor Detail

    - #### PairedStats

          public PairedStats(double sig)

      Creates a new PairedStats object with the supplied significance level.
      Parameters:
        `sig` - the significance level for comparisons

  - ### Method Detail

    - #### setDegreesOfFreedom

          public void setDegreesOfFreedom(int d)

      Sets the degrees of freedom (if calibration is required).

    - #### getDegreesOfFreedom

          public int getDegreesOfFreedom()

      Gets the degrees of freedom.

    - #### add

          public void add(double value1,
                 double value2)

      Add an observed pair of values.
      Parameters:
        `value1` - the value from column 1
        `value2` - the value from column 2

    - #### subtract

          public void subtract(double value1,
                      double value2)

      Removes an observed pair of values.
      Parameters:
        `value1` - the value from column 1
        `value2` - the value from column 2

    - #### add

          public void add(double[] value1,
                 double[] value2)

      Adds an array of observed pair of values.
      Parameters:
        `value1` - the array containing values from column 1
        `value2` - the array containing values from column 2

    - #### subtract

          public void subtract(double[] value1,
                      double[] value2)

      Removes an array of observed pair of values.
      Parameters:
        `value1` - the array containing values from column 1
        `value2` - the array containing values from column 2

    - #### calculateDerived

          public void calculateDerived()

      Calculates the derived statistics (significance etc).

    - #### toString

          public java.lang.String toString()

      Returns statistics on the paired comparison.
      Overrides:
        `toString` in class `java.lang.Object`
      Returns:
        the t-test statistics as a string

    - #### getRevision

          public java.lang.String getRevision()

      Returns the revision string.
      Specified by:
        `getRevision` in interface `RevisionHandler`
      Returns:
        the revision

    - #### main

          public static void main(java.lang.String[] args)

      Tests the paired stats object from the command line. reads line from stdin, expecting two values per line.
      Parameters:
        `args` - ignored.