c45learner.java

著名的开源仿真软件yale

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2002, 2003
 *      Simon Fischer, Ralf Klinkenberg, Ingo Mierswa, 
 *          Katharina Morik, Oliver Ritthoff
 *      Artificial Intelligence Unit
 *      Computer Science Department
 *      University of Dortmund
 *      44221 Dortmund,  Germany
 *  email: [e-mail]
 *  web:   http://yale.cs.uni-dortmund.de/
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 */
package edu.udo.cs.yale.operator.learner;

import edu.udo.cs.yale.operator.parameter.*;
import edu.udo.cs.yale.operator.OperatorException;
import edu.udo.cs.yale.operator.FatalException;
import edu.udo.cs.yale.operator.learner.decisiontree.RuleSet;
import edu.udo.cs.yale.operator.learner.decisiontree.Rule;
import edu.udo.cs.yale.example.ExampleReader;
import edu.udo.cs.yale.example.ExampleSet;
import edu.udo.cs.yale.example.Example;
import edu.udo.cs.yale.example.Attribute;
import edu.udo.cs.yale.tools.LogService;
import edu.udo.cs.yale.tools.TempFileService;
import edu.udo.cs.yale.tools.Ontology;
import edu.udo.cs.yale.tools.ParameterService;
import edu.udo.cs.yale.tools.Tools;

import java.util.List;
import java.util.Iterator;
import java.io.*;


/** <code>C45Learner</code> encapsulates the 
 *  <a TARGET="_top" href="http://www.cse.unsw.edu.au/~quinlan/">C4.5</a> program version 8
 *  by Ross Quinlan {@yale.cite Quinlan/93b}.
 *  It generates all input files required by C4.5 containing attribute names,
 *  ranges, and data and starts an external process to invoke C4.5.
 *  The output of C4.5 is parsed into a {@link edu.udo.cs.yale.operator.learner.decisiontree.RuleSet}
 *  which is a subclass of {@link Model} and can be applied without further calling of
 *  external programs.
 *
 *  @yale.xmlclass C45Learner
 *  @yale.reference Quinlan/93b
 *  @see     edu.udo.cs.yale.operator.learner.decisiontree.RuleSet
 *  @author  Ingo Mierswa
 *  @version $Id: C45Learner.java,v 2.6 2003/08/14 10:24:57 fischer Exp $
 */
public class C45Learner extends Learner {

    /** Parameters without value.
     */
    static final String[] SINGLE_PARAMETER = { "u", "s", "p", "g" };

    /** Parameters which need a value.
     */
    static final String[] PARAMETER = { "m", "c" };

    /** Starts the external process and feeds parameters and data to stdin.
     *  @return A RuleSet
     */
    public Model learn(ExampleSet exampleSet) throws OperatorException {
	LogService.logMessage("C4.5 learner '"+getName()+"':  "          
			      +"starts learning.", LogService.TASK); 

	// ---- Eingabedateien des C4.5 erzeugen ----
	File[] files = new File[2];
	String[] extensions = { ".names", ".data" };
        String filestem = TempFileService.createTempFiles(getName()+"_", extensions, files);

	writeExamples(exampleSet, files);

	// ---- Prozess erzeugen ----
	String learnCommand = ParameterService.getProperty("yale.c45.learncommand");
	String ruleCommand = ParameterService.getProperty("yale.c45.rulecommand");
	String parameterString = parseParameters();

	// c4.5 process
	try {
	    Process process = null;
	    process = Runtime.getRuntime().exec(learnCommand + " " + parameterString + " " + "-f " + filestem);
	    // ---- get Output ----
	    BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
	    String output = Tools.readOutput(in);
	    if ((output==null)||(output.equals(""))) 
		LogService.logMessage("C4.5 learner '" + getName() + "':  "              
				      + "No output of C4.5.", LogService.WARNING);	
	    in.close();
	    LogService.logMessage("Output of C4.5 (Learner: '"+getName()+"')\n"+output, LogService.MINIMUM);
	} catch (IOException e) { 
	    throw new FatalException("C4.5Learner '" + getName() + "':  "            
				     + "Error in c4.5 process: " + learnCommand, e); 
	}

	// c4.5 rules process
	try {
	    Process process = Runtime.getRuntime().exec(ruleCommand + " " + "-f " + filestem);
	    BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
	    RuleSet rules = RuleSet.parseC45Rules(in, exampleSet);
	    in.close();
	    Tools.waitForProcess(this, process, "c45rules");
	    LogService.logMessage("C4.5 learner '"+getName()+"':  C4.5 has succesfully " 
				  +"learned an example set.", LogService.TASK);        
	    return rules;
	} catch (IOException e) { 
	    throw new FatalException("C4.5 learner '" + getName() + "':  "            
				     + "Error in c4.5rules process: " + ruleCommand, e);
	}
    }

    /** Constructs a parameter string from the parameters set in the configuration file. */
    private String parseParameters() {
	String params="";
	for (int i = 0; i < SINGLE_PARAMETER.length; i++) {
	    String value = getParameterAsString(SINGLE_PARAMETER[i]);
	    if (value != null) params += SINGLE_PARAMETER[i];
	} 
	for (int i = 0; i < PARAMETER.length; i++) {
	    String value = getParameterAsString(PARAMETER[i]);
	    if (value != null) params += PARAMETER[i] + value;
	} 
	return params;
    }

    /** First writes names and ranges of the attributs in the format <br>
     *  class1,class2,...,classN. <br>
     *  att1: range1. <br>
     *  att2: range2. <br>
     *  ... <br>
     *  to the file "filestem.names" and then writes the examples in the format<br>
     *  att1,att2,...,
     */
    private void writeExamples(ExampleSet exampleSet, File[] files) throws OperatorException {

	// ---- Schreiben der Namen und Bereiche in filestem.names ----
	try {
	    PrintWriter nameout = new PrintWriter(new FileWriter(files[0]));
	    
	    // classes
	    Iterator classes = exampleSet.getLabel().getValuesAsString().iterator();
	    while (classes.hasNext()) {
		String classString = (String)classes.next();
		nameout.print(classString);
		if (classes.hasNext()) nameout.print(",");
	    }
	    nameout.println(".");
	    
	    // namen und bereiche
	    for (int n = 0; n < exampleSet.getNumberOfAttributes(); n++) {
		Attribute attribute = exampleSet.getAttribute(n);
		nameout.print(attribute.getName()+": ");
		
		if (Ontology.ATTRIBUTE_VALUE_TYPE.isA(attribute.getValueType(), Ontology.NUMERICAL)) {
		    nameout.print("continuous");
		} else {
		    Iterator values = attribute.getValuesAsString().iterator();
		    while (values.hasNext()) {
			String valueString = (String)values.next();
			nameout.print(valueString);
			if (values.hasNext()) nameout.print(",");
		    }
		}
		nameout.println(".");
	    } 
	    
	    nameout.close();
	} catch (java.io.IOException e) { 
	    throw new FatalException("C45Learner [parseExamples(ExampleSet, PrintStream)] '"+getName()+
				     "': There was an exception by writing the data in "+
				     files[0].getName() + "!", e);
	}

	// ---- Schreiben der Daten in filestem.data ----
	try {
	    PrintWriter dataout = new PrintWriter(new FileWriter(files[1]));
	    
	    ExampleReader r = exampleSet.getExampleReader();
	    
	    while (r.hasNext()) {
		// ---- Beispiel auslesen ----
		Example example = (Example)r.next();
		if (example==null)  {
		    throw new FatalException("C45Learner [parseExamples(ExampleSet, String)] '" + getName() + "': "
					     +"example is null!");
		}
		
		// ---- Attribute bestimmen und rausschreiben ----
		String attributes = example.getAttributesAsString(",");
		if ((attributes==null) || (attributes.equals("")))  {
		    throw new FatalException("C45Learner [parseExamples(ExampleSet, PrintStream)] '" + getName() + "': "
					     +"There are no attributes of example!");
		}
		
		// ---- Label bestimmen und rausschreiben ----
		String label = example.getLabelAsString();
		dataout.print(attributes);
		dataout.println(","+label + ".");
	    }
	    dataout.close();
	} catch (java.io.IOException e) { 
	    throw new FatalException("C45Learner [parseExamples(ExampleSet, PrintStream)] '" + getName() +
				     "': There was an exception by writing the data in " + 
				     files[1].getName() + "!", e);
	}
    }

    public List getParameterTypes() {
	List types = super.getParameterTypes();

	for (int i = 0; i < SINGLE_PARAMETER.length; i++)
	    types.add(new ParameterTypeString(SINGLE_PARAMETER[i], "The C4.5 parameter "+SINGLE_PARAMETER[i]+" (no value needed)."));
	for (int i = 0; i < PARAMETER.length; i++)
	    types.add(new ParameterTypeString(PARAMETER[i], "The C4.5 parameter "+PARAMETER[i]+"."));

	return types;
    }
}