idtagging.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.preprocessing;

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.Attribute;
import edu.udo.cs.yale.example.Example;
import edu.udo.cs.yale.example.ExampleSet;
import edu.udo.cs.yale.example.ExampleReader;
import edu.udo.cs.yale.tools.Ontology;
import edu.udo.cs.yale.tools.LogService;

import java.util.List;

/** This operator adds an ID attribute to the given example set. Each example is tagged with an incremental integer number. 
 *  If the example set already contains an id attribute, the old attribute will be removed before the new one is added.
 *  
 *  @version $Id: IdTagging.java,v 1.4 2004/09/09 12:00:53 ingomierswa Exp $
 */
public class IdTagging extends Operator {

    private static final Class[] INPUT_CLASSES = { ExampleSet.class };
    private static final Class[] OUTPUT_CLASSES = { ExampleSet.class };

    public IOObject[] apply() throws OperatorException {
	ExampleSet eSet = (ExampleSet)getInput(ExampleSet.class, false);

	// only warning, removing is done by createSpecialAttribute(...)
	Attribute idAttribute = eSet.getIdAttribute();
	if (idAttribute != null) {
	    LogService.logMessage("Overwriting old id attribute!",
				  LogService.WARNING);
	}

	// create new id attribute
	boolean nominalIds = getParameterAsBoolean("create_nominal_ids");
	idAttribute = eSet.createSpecialAttribute(ExampleSet.ID_NAME, nominalIds ? Ontology.NOMINAL : Ontology.INTEGER);

	// set IDs
	int currentId = 1;
	ExampleReader r = eSet.getExampleReader();
	while (r.hasNext()) {
	    Example example = r.next();
	    example.setValue(idAttribute, nominalIds ? idAttribute.mapString("id_" + currentId) : currentId);
	    currentId++;
	}

	eSet.recalculateAttributeStatistics(idAttribute);

	return new IOObject[0];
    }

    public Class[] getInputClasses() { return INPUT_CLASSES; }
    public Class[] getOutputClasses() { return OUTPUT_CLASSES; }

    public List getParameterTypes() {
	List types = super.getParameterTypes();
	ParameterType type = new ParameterTypeBoolean("create_nominal_ids", "True if nominal ids (instead of integer ids) should be created", false);
	type.setExpert(false);
	types.add(type);
	return types;
    }
}