examplesetwriter.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.ExampleSet;
import edu.udo.cs.yale.example.ExampleReader;
import edu.udo.cs.yale.example.ExampleFormatter;
import edu.udo.cs.yale.example.SparseFormatDataRowReader;
import edu.udo.cs.yale.tools.LogService;

import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.io.IOException;
import java.util.List;
import java.util.Iterator;
import java.util.Collection;

/** Writes values of all examples in an {@link ExampleSet} to a file. Dense, sparse,
 *  and user defined formats (specified by the parameter 'format') can be used. 
 *  Attribute description files may be generated for dense and sparse format as well.
 *  These formats can be read using the {@link ExampleSource} and 
 *  {@link SparseFormatExampleSource} operators.
 *
 *  <dl>
 *    <dt>dense:</dt><dd>
 *        Each line of the generated data file is of the form<br/>
 *        <center><pre>value1 value2 ... valueN label predicted weight cluster</pre></center>
 *    </dd>
 *    <dt>sparse:</dt><dd>Only non 0 values are written to the file, prefixed by a column index. See 
 *        the description of {@link SparseFormatExampleSource} for details.
 *    </dd>
 *    <dt>special:</dt><dd>Using the parameter 'special_format', the user can specify the exact 
 *        format. The $ sign has a special meaning and introduces a command (the following character)
 *        Additional arguments to this command may be supplied enclosing it in square brackets.
 *  <dl>
 *    <dt>$a[separator]:</dt><dd> All attributes separated by separator</dd>
 *    <dt>$s[separator][indexSeparator]:</dt><dd> Sparse format. For all non zero 
 *           attributes the following strings are concatenated: 
 *           the column index, the value of indexSeparator, the attribute value. Attributes
 *           are separated by separator.</dd>
 *    <dt>$v[name]:</dt><dd> The value of the named attribute</dd>
 *    <dt>$c[index]:</dt><dd> The value of the attribute with the given index</dd>
 *    <dt>$l:</dt><dd> The label</dd>
 *    <dt>$p:</dt><dd> The predicted label</dd> 
 *    <dt>$i:</dt><dd> The id</dd>
 *    <dt>$w:</dt><dd> The weight</dd>
 *    <dt>$n:</dt><dd> The newline character</dd>
 *    <dt>$t:</dt><dd> The tabulator character</dd>
 *    <dt>$$:</dt><dd> The dollar sign</dd>
 *    <dt>$[:</dt><dd> The '[' character</dd>
 *    <dt>$]:</dt><dd> The ']' character</dd>
 *  </dl> 
 *    Make sure the format string ends with $n if you want examples to be separated by newlines!</dd>
 *  </dl>
 *
 *  @yale.xmlclass ExampleSetWriter
 *  @see edu.udo.cs.yale.example.ExampleSet
 *  @author Simon, Ingo
 *  @version $Id: ExampleSetWriter.java,v 1.2 2004/08/27 11:57:37 ingomierswa Exp $
 */
public class ExampleSetWriter extends Operator {

    /** Diese Klassen m&uuml;ssen mindestens in apply &uuml;bergeben werden. */
    private static final Class[] INPUT_CLASSES = { ExampleSet.class };

    /** Diese Klasse werden in dem Outputarray zur&uuml;ckgeliefert. */
    private static final Class[] OUTPUT_CLASSES = { ExampleSet.class };

    private static String[] formatNames;
    
    static {
	formatNames = new String[SparseFormatDataRowReader.FORMAT_NAMES.length+2];
	formatNames[0] = "dense";
	for (int i = 0; i < SparseFormatDataRowReader.FORMAT_NAMES.length; i++) {
	    formatNames[i+1] = "sparse_"+SparseFormatDataRowReader.FORMAT_NAMES[i];
	}
	formatNames[formatNames.length-1] = "special_format";
    }

    private String filename;
    private String attDescFile;

    public IOObject[] apply() throws OperatorException {
	ExampleSet eSet = (ExampleSet)getInput(ExampleSet.class, false);
	filename    = getParameterAsString("example_set_file");
	attDescFile = getParameterAsString("attribute_description_file");

	try {
	    // write example set
	    File dataFile = getExperiment().resolveFileName(filename);
	    File attFile = (attDescFile != null) ? getExperiment().resolveFileName(attDescFile) : null;
	    int format = getParameterAsInt("format");
	    if (format == 0) {
		eSet.writeToFile(dataFile, attFile);
	    } else if (format == formatNames.length-1) {
		if (attDescFile != null) 
		    logMessage("special_format used. Ignoring attribute description file.",
			       LogService.ERROR);
		writeSpecialFormat(eSet, dataFile);
	    } else {
		eSet.writeToFileSparse(format-1, dataFile, attFile);
	    }
	} catch (IOException e) {
	    throw new UserError(this, e, 303, new Object[] {filename+" / "+attDescFile, e.getMessage()});
	}
	
	return new IOObject[0];
    }

    private void writeSpecialFormat(ExampleSet exampleSet, File dataFile) throws OperatorException {
	String format = getParameterAsString("special_format");
	if (format == null) 
	    throw new UserError(this, 201, new Object[] { "special_format", "format", "special_format"} );
	ExampleFormatter formatter;
	try {
	    formatter = ExampleFormatter.compile(format, exampleSet);
	} catch (Throwable e) {
	    throw new UserError(this, 901, format, e.getMessage());
	}
	try {
	    PrintWriter out = new PrintWriter(new FileWriter(dataFile));
	    ExampleReader reader = exampleSet.getExampleReader();
	    while (reader.hasNext())
		out.print(formatter.format(reader.next()));
	    out.close();
	} catch (IOException e) {
	    throw new UserError(this, e, 301, new Object[] {dataFile,e.getMessage()});
	}
    }

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

    public List getParameterTypes() {
	List types = super.getParameterTypes();
	types.add(new ParameterTypeFile("example_set_file", "File to save the example set to.", false));
	types.add(new ParameterTypeFile("attribute_description_file", "File to save the attribute descriptions to.", true));
	types.add(new ParameterTypeCategory("format", "Format to use for output.", formatNames, 0));
	types.add(new ParameterTypeString("special_format", "Format string to use for output.", true));
	return types;
    }
}