individualoperator.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.features;

import edu.udo.cs.yale.example.ExampleSet;
import edu.udo.cs.yale.example.AttributeWeightedExampleSet;

import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;

/** A <tt>PopulationOperator</tt> that modifies a population by modifying
 *  all individuals independently. The modifications can be made each per attribute block
 *  or for single attributes.
 *
 *  @author Simon, Ingo
 *  @version $Id: IndividualOperator.java,v 2.10 2004/08/27 11:57:36 ingomierswa Exp $ <br>
 */
public abstract class IndividualOperator implements PopulationOperator {

    /** Subclasses must implement this method providing a list of new
     *  individuals (of class ExampleSet). <tt>exampleSet</tt> will be removed
     *  from the population so it might be useful to return a list of size 1 containing
     *  only the modified <tt>exampleSet</tt>. */
    public abstract List operate(AttributeWeightedExampleSet exampleSet) throws Exception;

    /** Operates on all individuals, removes the original individuals and
     *  adds the new ones. */
    public void operate(Population pop) throws Exception {
	List newIndividuals = new LinkedList();
	for (int i = 0; i < pop.getNumberOfIndividuals(); i++) {
	    List individuals = operate(pop.get(i));
	    newIndividuals.addAll(individuals);
	}
	pop.clear();
	ListIterator i = newIndividuals.listIterator();
	while (i.hasNext())
	    pop.add((AttributeWeightedExampleSet)i.next());
    }

    /** The default implementation returns true for every generation. */
    public boolean performOperation(int generation) { return true; }
}