/***********************************************************************
This file is part of JavaNPST, a Java library of NonParametric
Statistical Tests.
Copyright (C) 2011
J. Derrac (jderrac@decsai.ugr.es)
S. Garcia (sglopez@ujaen.es)
F. Herrera (herrera@decsai.ugr.es)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/
**********************************************************************/
package javanpst.tests.goodness.chiSquareTest;
import javanpst.data.structures.dataTable.DataTable;
import javanpst.distributions.DistributionDefinitions;
import javanpst.distributions.common.continuous.ChiSquareDistribution;
import javanpst.distributions.common.discrete.BinomialDistribution;
import javanpst.distributions.common.discrete.GeometricDistribution;
import javanpst.distributions.common.discrete.PoissonDistribution;
import javanpst.distributions.common.discrete.UniformDistribution;
import javanpst.tests.StatisticalTest;
/**
* The Chi-square test.
*
* This goodness of fit can be used to test if a given sample follows
* a discrete distribution. This implementation allow to adjust the data
* to a uniform, binomial, poisson or geometric distribution.
*
* @author Joaqu�n Derrac Rus (jderrac@decsai.ugr.es)
* @version 1.0
*/
public class ChiSquareTest extends StatisticalTest{
/**
* Data to fit
*/
private DataTable data;
/**
* Type of distribution to fit
*/
private int typeDist;
/**
* Number of degrees of the chi-square distribution
*/
private int freedomDegree;
/**
* Number of estimated parameters
*/
private int nEstimated;
/**
* Number of values in the sample
*/
private int nCount;
/**
* Error obtained in each category
*/
private double errorTable [][];
/**
* distribution defined by data
*/
private double distribution [][];
/**
* Tests if the distribution to adjust is completely defined
*/
private boolean distributionReady;
/**
* Q statistic
*/
private double Q;
/**
* P-value of the test
*/
private double pValue;
/**
* Uniform distribution
*/
private UniformDistribution uniform;
/**
* Binomial distribution
*/
private BinomialDistribution binomial;
/**
* Poisson distribution
*/
private PoissonDistribution poisson;
/**
* Geometric distribution
*/
private GeometricDistribution geometric;
/**
* Chi-square distribution
*/
private ChiSquareDistribution chiSquare;
/**
* Default builder
*/
public ChiSquareTest(){
setReportFormat();
clearData();
}//end-method
/**
* Clears the data stored in the test
*/
public void clearData(){
data=new DataTable();
performed=false;
dataReady=false;
distributionReady=false;
typeDist=-1;
freedomDegree=0;
nEstimated=0;
errorTable=null;
pValue=-1.0;
}//end-method
/**
* Builder. Load data to test.
*
* @param newData data to test.
*/
public ChiSquareTest(DataTable newData){
setReportFormat();
data=DataTable.newInstance(newData);
if(data.getColumns()!=2){
System.out.println("Chi-square test only accept tables in the following format:");
System.out.println(" ");
clearData();
return;
}
for(int i=0;i0){
System.out.println("No null values allowed in this test.");
clearData();
return;
}
}
errorTable = new double [data.getRows()][2];
distribution = new double [data.getRows()][2];
nCount=0;
for(int i=0;i ");
clearData();
return;
}
for(int i=0;i0){
System.out.println("No null values allowed in this test.");
clearData();
return;
}
}
errorTable = new double [data.getRows()][2];
distribution = new double [data.getRows()][2];
nCount=0;
for(int i=0;i0 && less=1.0 && pointerdistribution[j][0]){
swapRow(distribution[i][0],distribution[i][1],distribution[j][0],distribution[j][1]);
}
}
}
}//end-method
/**
* Swaps two rows of the distribution table
*
* @param a1 first row, first column value
* @param a2 first row, second column value
* @param b1 second row, first column value
* @param b2 second row, second column value
*/
private void swapRow(double a1,double a2,double b1, double b2){
double aux1,aux2;
aux1=a1;
a1=b1;
b1=aux1;
aux2=a2;
a2=b2;
b2=aux2;
}//end-method
/**
* Get Q statistic
*
* @return Q Statistic
*/
public double getQ(){
return Q;
}//end-method
/**
* Get p-value of the test
*
* @return p-value computed
*/
public double getPValue(){
return pValue;
}//end-method
/**
* Prints the data stored in the test
*
* @return Data stored
*/
public String printData(){
String text="";
text+="\n"+data;
return text;
}//end-method
/**
* Prints a report with the results of the test
*
* @return Output report
*/
public String printReport(){
String report="";
if(!performed){
report+="The test has not been performed.\n";
return report;
}
report+="\n************\n";
report+="Chi-square goodness of fit test\n";
report+="**************\n\n";
switch(typeDist){
case DistributionDefinitions.UNIFORM:
report+="Fitting data to Uniform distribution (N="+nf6.format(uniform.getN())+")\n\n";
break;
case DistributionDefinitions.BINOMIAL:
report+="Fitting data to Binomial distribution (N="+nf6.format(binomial.getN())+" , P="+nf6.format(binomial.getP())+")\n\n";
break;
case DistributionDefinitions.POISSON:
report+="Fitting data to Poisson distribution (Mean="+nf6.format(poisson.getMean())+")\n\n";
break;
case DistributionDefinitions.GEOMETRIC:
report+="Fitting data to Geometric distribution (P="+nf6.format(geometric.getP())+")\n\n";
break;
}
report+="Q Statistic: "+nf6.format(Q)+"\n\n";
report+="P-Value : "+nf6.format(pValue)+"\n";
return report;
}//end-method
}//end-class
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