doublearraydatarow.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;

/** Implementation of DataRow that is backed by a double array. 
 *  @version $Id: DoubleArrayDataRow.java,v 2.5 2004/08/27 11:57:31 ingomierswa Exp $ 
 */
public class DoubleArrayDataRow implements DataRow {

    private double[] data;

    public DoubleArrayDataRow(double[] data) {
	this.data = data;
    }

    public double get(Attribute attribute) {
	return data[attribute.getIndex()];
    }

    public void set(Attribute attribute, double value) {
	data[attribute.getIndex()] = value;
    }

    public void ensureNumberOfColumns(int numberOfColumns) {
	if (data.length >= numberOfColumns) return;
	double[] newData = new double[numberOfColumns];
	System.arraycopy(data, 0, newData, 0, data.length);
	data = newData;
    }

    public String toString() {
	StringBuffer result = new StringBuffer();
	for (int i = 0; i < data.length; i++) 
	    result.append((i==0?"":",")+data[i]);
	return result.toString();
    }
}