attributeweightswriter.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.io;

import edu.udo.cs.yale.operator.Operator;
import edu.udo.cs.yale.operator.IOObject;
import edu.udo.cs.yale.operator.OperatorException;
import edu.udo.cs.yale.operator.UserError;
import edu.udo.cs.yale.operator.parameter.*;
import edu.udo.cs.yale.example.AttributeWeights;

import java.io.*;
import java.util.List;

/** Writes the weights of all attributes of an example set to a file. Therefore a {@link AttributeWeights} object
 *  is needed in the input of this operator. Each line holds the name of one attribute and its weight.
 *  This file can be read in another experiment using the {@link AttributeWeightsLoader} 
 *  and the {@link edu.udo.cs.yale.operator.features.AttributeWeightsApplier}.
 *
 *  @version $Id: AttributeWeightsWriter.java,v 1.2 2004/08/27 11:57:37 ingomierswa Exp $
 */
public class AttributeWeightsWriter extends Operator {

    private static final Class[] INPUT_CLASSES  = { AttributeWeights.class };
    private static final Class[] OUTPUT_CLASSES = { AttributeWeights.class };


    /** Writes the attribute set to a file. */
    public IOObject[] apply() throws OperatorException {
	String weightFileName    = getParameterAsString("attribute_weights_file"); 
	File weightFile          = getExperiment().resolveFileName(weightFileName);
  	AttributeWeights weights = (AttributeWeights)getInput(AttributeWeights.class, false);

	try {
	    weights.save(weightFile);
	} catch (IOException e) {
	    throw new UserError(this, e, 303, new Object[] { weightFile, e.getMessage() });
	}

	return new IOObject[0];
    }

    public Class[] getInputClasses() {  return INPUT_CLASSES;  }
    public Class[] getOutputClasses() { return OUTPUT_CLASSES; }

    public List getParameterTypes() {
	List types = super.getParameterTypes();
	types.add(new ParameterTypeFile("attribute_weights_file", "Filename for the attribute weight file.", false));
	return types;
    }
}