ir.utilities
Class Stats

java.lang.Object
  ir.utilities.Stats

public class Stats
extends java.lang.Object

A place to put statistical routines

Constructor Summary

Stats()

Method Summary

static double	covariance(double[] x, double[] y) Return the covariance between the vectors x and y.
static double	mean(double[] values) Return the arithmetic mean of the argument values.
static double	pearsonCorrelation(double[] x, double[] y) Return the Pearson Correlation between the vectors x and y.
static double	standardDeviation(double[] values) Return the standard deviation of the argument values.

Methods inherited from class java.lang.Object

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

Constructor Detail

Stats

public Stats()

Method Detail

mean

public static double mean(double[] values)

Return the arithmetic mean of the argument values.

standardDeviation

public static double standardDeviation(double[] values)

Return the standard deviation of the argument values. Standard deviation is the square root of the variance.

covariance

public static double covariance(double[] x,
                                double[] y)

Return the covariance between the vectors x and y.

pearsonCorrelation

public static double pearsonCorrelation(double[] x,
                                        double[] y)

Return the Pearson Correlation between the vectors x and y.