c45examplesource.java

一个很好的LIBSVM的JAVA源码。对于要研究和改进SVM算法的学者。可以参考。来自数据挖掘工具YALE工具包。

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2001-2004
 *      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.io;

import edu.udo.cs.yale.operator.Operator;
import edu.udo.cs.yale.operator.IOObject;
import edu.udo.cs.yale.operator.OperatorException;
import edu.udo.cs.yale.operator.parameter.*;
import edu.udo.cs.yale.example.ExampleSet;
import edu.udo.cs.yale.tools.WekaTools;


import weka.core.converters.C45Loader;
import weka.core.Instances;

import java.util.List;
import java.io.IOException;

/** Loads data given in C4.5 format (names and data file). Both files must be in the same directory. You can specify one
 *  of the C4.5 files (either the data or the names file) or only the filestem. This operator internally uses the 
 *  C45Loader of Weka. 
 *
 *  @version $Id: C45ExampleSource.java,v 1.1 2004/09/01 16:04:46 ingomierswa Exp $
 */
public class C45ExampleSource extends Operator {
    
    public IOObject[] apply() throws OperatorException {
	C45Loader loader = new C45Loader();
	loader.reset();
	try {
	    loader.setSource(getExperiment().resolveFileName(getParameterAsString("c45_filestem")));
	} catch (IOException e) {
	    throw new OperatorException("Cannot load C4.5 data: " + e.getMessage(), e);
	}
	ExampleSet result = null;
	try {
	    Instances instances = loader.getDataSet();
	    result = WekaTools.toYaleExampleSet(instances);
	} catch (Exception e) {
	    throw new OperatorException("Cannot convert to principal components: " + e);
	}
	return new IOObject[] { result };
    }
    
    public Class[] getInputClasses() { return new Class[0]; }
    public Class[] getOutputClasses() { return new Class[] { ExampleSet.class }; }

    public List getParameterTypes() {
	List types = super.getParameterTypes();
	types.add(new ParameterTypeFile("c45_filestem", 
					"The path to either the C4.5 names file, the data file, or the filestem (without extensions). Both files must be in the same directory.", 
					false));
	return types;
    }
}