weightedlayer.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.learner.nn;

public class WeightedLayer extends Layer {

    /** weight[i][j] = weight of the i-th neuron for the j-th input. */
    private double weight[][];
    
    private double[] u;

    public WeightedLayer(int input, int output, Trafo trafo, Layer succ) {
	super(output, trafo, succ);
	u = new double[output];
	weight = new double[output][input];
	java.util.Random r = new java.util.Random();
	for (int i = 0; i < output; i++) {
	    for (int j = 0; j < input; j++) {
		weight[i][j] = r.nextDouble()*2 - 1;		
	    }
	}
    }

    public double[] calculate(double[] s) {
	// for all neurons
	for (int i = 0; i < weight.length; i++) {
	    u[i] = 0;
	    // for all input neurons
	    for (int j =0; j < weight[i].length; j++) {
		u[i] += weight[i][j] * s[j];
	    }
	}
	return u;
    }

    public double[][] weights() { return weight; }

    public String toString() {
	String str = "";
	for (int j = 0; j < weight[0].length; j++) {
	    for (int i = 0; i < weight.length; i++) {
		str += weight[i][j] + " | ";
	    }
	    str += "\n";
	}
	return str;
    }
}