/***********************************************************************
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.distributions.tests;
import java.io.IOException;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.SAXException;
import javanpst.distributions.DistributionDefinitions;
import javanpst.data.distributions.criticalTable.Critical1KeyTable;
import javanpst.data.distributions.incompleteTable.Incomplete3KeyTable;
import javanpst.data.readers.distributionReaders.KolmogorovTwoSampleAsymptoticalReaderFormat;
import javanpst.data.readers.distributionReaders.KolmogorovTwoSampleReaderFormat;
/**
* An implementation of the Kolmogorov distribution for two samples.
*
* Uses a Singleton pattern to ensure only an instance of the class is allowed.
*
* @author Joaqu�n Derrac Rus (jderrac@decsai.ugr.es)
* @version 1.0
*/
public class KolmogorovTwoSampleDistribution extends TestDistribution{
/**
* Table of the Kolmogorov distribution
*/
private static Incomplete3KeyTable exactTable;
/**
* Table of critical values the Kolmogorov distribution
*/
private static Critical1KeyTable table;
/**
* Private default builder.
*
* Initializes distribution tables
*/
private KolmogorovTwoSampleDistribution(){
initialize();
}//end-method
/**
* Singleton pattern access to the distribution
*
* @return the instance of the distribution
*/
public static KolmogorovTwoSampleDistribution getInstance(){
return SingletonHolder.distribution;
}//end-method
/**
* Singleton holder for the only instance of the distribution
*
* SingletonHolder is loaded on the first execution of getInstance()
* or the first access to SingletonHolder.distribution, not before.
*/
private static class SingletonHolder {
public static final KolmogorovTwoSampleDistribution distribution = new KolmogorovTwoSampleDistribution();
}//end-method
/**
* Generate distribution tables
*/
protected void generateTables(){
double [] tags={0.200,0.100,0.050,0.020,0.010};
table=new Critical1KeyTable(21,tags);
exactTable = new Incomplete3KeyTable(9,9,65);
loadFiles();
}//end-method
/**
* Load data files to fill distribution tables
*/
protected void loadFiles(){
try{
SAXParserFactory spf=SAXParserFactory.newInstance();
SAXParser sp = spf.newSAXParser();
sp.parse(this.getClass().getResourceAsStream("/tables/Kolmogorov/TwoSampleAsymptotical.xml"), new KolmogorovTwoSampleAsymptoticalReaderFormat());
}catch(ParserConfigurationException e){
System.err.println("Parser error");
}catch(SAXException e2){
System.err.println("SAX error: " + e2.getStackTrace());
} catch (IOException e3) {
System.err.println("Input/Output error: " + e3.getMessage() );
}
try{
SAXParserFactory spf=SAXParserFactory.newInstance();
SAXParser sp = spf.newSAXParser();
sp.parse(this.getClass().getResourceAsStream("/tables/Kolmogorov/TwoSample.xml"), new KolmogorovTwoSampleReaderFormat());
}catch(ParserConfigurationException e){
System.err.println("Parser error");
}catch(SAXException e2){
System.err.println("SAX error: " + e2.getStackTrace());
} catch (IOException e3) {
System.err.println("Input/Output error: " + e3.getMessage() );
}
}//end-method
/**
* Gets the table of the critical values distribution
*
* @return Reference to the table
*/
public static Critical1KeyTable getTable(){
return table;
}//end-method
/**
* Gets the table of the distribution
*
* @return Reference to the table
*/
public static Incomplete3KeyTable getExactTable(){
return exactTable;
}//end-method
/**
* Computes p-value of the Kolmogorov distribution.
*
* @param n size of the population
* @param Dn Kolmogorov statistic
* @return p-value computed
*/
public double computeExactProbability(int n,double Dn){
double nmDn;
int nmDnInteger;
double pValue;
if(n<9){
//exact table
nmDn=n*n*Dn;
nmDnInteger=(int)nmDn;
pValue=exactTable.get(n, n, nmDnInteger);
if(pValue==-1){
return DistributionDefinitions.ALL;
}
return pValue;
}
return DistributionDefinitions.ALL;
}//end-method
/**
* Computes p-value of the Kolmogorov distribution.
*
* @param n size of the population
* @param Dn Kolmogorov statistic
* @return p-value computed
*/
public double computeAsymptoticProbability(int n,double Dn){
double asymptoticValues []={1.07,1.22,1.36,1.52,1.63};
double nmDn;
if(n<21){
nmDn=n*n*Dn;
//asymptotic table
if(table.get(n, 0)==DistributionDefinitions.UNDEFINED){
return DistributionDefinitions.UNDEFINED;
}
for(int i=4;i>-1;i--){
if(nmDn>=table.get(n, i)){
return table.getHeader(i);
}
}
}
else{
//asymptotic distribution
double size=Math.sqrt((n+n)/(n*n));
for(int i=4;i>-1;i--){
if(Dn>=(asymptoticValues[i]/size)){
return table.getHeader(i);
}
}
}
return DistributionDefinitions.ALL;
}//end-method
}//end-class
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