weka.experiment
Class PairedStats

java.lang.Object
  weka.experiment.PairedStats

Direct Known Subclasses:

PairedStatsCorrected

public class PairedStats

extends java.lang.Object

A class for storing stats on a paired comparison (t-test and correlation)

Version:

$Revision: 1.6 $

Author:

Len Trigg (trigg@cs.waikato.ac.nz)

Field Summary

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

PairedStats(double sig)
Creates a new PairedStats object with the supplied significance level.

Method Summary

void	add(double value1, double value2) Add an observed pair of values.
void	calculateDerived() Calculates the derived statistics (significance etc).
static void	main(java.lang.String[] args) Tests the paired stats object from the command line.
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

clone, equals, finalize, 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

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

calculateDerived

public void calculateDerived()

Calculates the derived statistics (significance etc).

toString

public java.lang.String toString()

Returns statistics on the paired comparison.

Returns:

the t-test statistics as a string

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.