repicea.stats.estimates.CorrelationEstimate Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of repicea-mathstats Show documentation
Show all versions of repicea-mathstats Show documentation
Mathematical and statistical methods
/*
* This file is part of the repicea-statistics library.
*
* Copyright (C) 2009-2012 Mathieu Fortin for Rouge-Epicea
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This library is distributed with the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* Please see the license at http://www.gnu.org/copyleft/lesser.html.
*/
package repicea.stats.estimates;
import repicea.math.Matrix;
/**
* The CorrelationEstimate class represents a Pearson's correlation
* estimate.
* @author Mathieu Fortin - November 2012
*/
public class CorrelationEstimate extends SimpleEstimate {
private static final long serialVersionUID = 20110912L;
private int sampleSize;
/**
* Constructor.
* @param mean the mean correlation
* @param sampleSize the sample size
*/
public CorrelationEstimate(double mean, int sampleSize) {
super();
Matrix meanMat = new Matrix(1,1);
meanMat.setValueAt(0, 0, mean);
setMean(meanMat);
this.sampleSize = sampleSize;
}
/**
* This method returns the t value under the assumption that the true correlation is null.
* @return a double
*/
public double getStudentT() {
double mean = getMean().getValueAt(0, 0);
return mean * Math.sqrt((double) (sampleSize - 2)/(1 - mean * mean));
}
/**
* This method return the sample size.
* @return an integer
*/
public int getSampleSize() {return sampleSize;}
}