simpleweighting.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.weighting;

import edu.udo.cs.yale.operator.features.*;
import edu.udo.cs.yale.example.AttributeWeightedExampleSet;

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

/** This PopulationOperator realises a simple weighting, i.e. creates a list of clones of each individual
 *  and weights one attribute in each of the clones with some different weights.
 *
 *  @version $Id: SimpleWeighting.java,v 1.7 2004/08/27 11:57:37 ingomierswa Exp $
 */
public class SimpleWeighting extends IndividualOperator {

    /** If a weight is equal to this compare weight, all weights are used for building a new individual. */
    private double compareWeight = 0.0d;
    /** These weights are used for building new individuals. */
    private double[] weights = null;

    /** Creates a simple weighting. */
    public SimpleWeighting(double compareWeight, double[] weights) {
	this.compareWeight = compareWeight;
	this.weights       = weights;
    }

    public List operate(AttributeWeightedExampleSet exampleSet) {
	List l = new LinkedList();
	for (int i = 0; i < exampleSet.getNumberOfAttributes(); i++) {
	    int newIndex = i;
 	    if (exampleSet.getWeight(i) == compareWeight) {
		for (int w = 0; w < weights.length; w++) {
		    AttributeWeightedExampleSet nes = (AttributeWeightedExampleSet)exampleSet.clone();
		    newIndex = nes.setWeightForBlock(i, weights[w]);
		    l.add(nes);
		}
	    } 
	    i = newIndex;
	}
	return l;
    }
}