randomdatarowreader.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.example;

import edu.udo.cs.yale.tools.RandomGenerator;

import java.util.Iterator;

/** Create data rows based on random data in the range of the minimum and maximum values of the attributes.
 *
 *  @version $Id: RandomDataRowReader.java,v 2.3 2004/09/04 20:07:02 ingomierswa Exp $
 */
public class RandomDataRowReader implements DataRowReader {

    private Iterator iterator;
    private int size;
    private Attribute[] attributes;
    private int counter = 0;

    public RandomDataRowReader(Attribute[] attributes, int size) {
	this.attributes = attributes;
	this.size = size;
    }
    
    public boolean hasNext() {
	return (counter < size);
    }

    public DataRow next() {
	RandomGenerator random = RandomGenerator.getGlobalRandomGenerator();
	double[] data = new double[attributes.length];
	for (int i = 0; i < data.length; i++) {
	    data[i] = random.nextDoubleInRange(attributes[i].getMinimum(), attributes[i].getMaximum());
	}
	return new DoubleArrayDataRow(data);
    }
}