examplesetiterator.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;

import edu.udo.cs.yale.tools.LogService;
import edu.udo.cs.yale.example.ExampleSet;

import java.util.*;

/** For each example set the ExampleSetIterator finds in its input, the inner operators are 
 *  applied as if it was a {@link SimpleOperatorChain}. This operator can be used to conduct
 *  an experiment consecutively on a number of different data sets.
 *
 *  @author ingo
 *  @version $Id: ExampleSetIterator.java,v 2.9 2004/08/27 11:57:34 ingomierswa Exp $
 */
public class ExampleSetIterator extends OperatorChain {

    private List eSetList;

    /** Returns the maximum number of innner operators. */
    public int getMaxNumberOfInnerOperators() { return 1; }
    /** Returns the minimum number of innner operators. */
    public int getMinNumberOfInnerOperators() { return 1; }

    public Class[] getOutputClasses() { return new Class[0]; }
    public Class[] getInputClasses() { return new Class[] { ExampleSet.class }; }

    public IOObject[] apply() throws OperatorException {
	LogService.logMessage(getName() + ": Starts iteration over example sets", LogService.TASK);

	eSetList = new LinkedList();
	IOObject eSet = null;
	try {
	    while (true) {
		eSet = getInput(ExampleSet.class);
		eSetList.add(eSet);
	    }
	} catch (MissingIOObjectException e) {
	    LogService.logMessage("No more example sets found. Use " + eSetList.size() + " example sets.", LogService.STATUS);
	}

	Iterator i = eSetList.iterator();
	IOContainer innerResult = new IOContainer(new IOObject[0]);
	while (i.hasNext()) {
	    IOContainer result = getOperator(0).apply(new IOContainer(new IOObject[] { (IOObject)i.next() }));
	    innerResult = innerResult.append(result.getIOObjects());
	}
	return innerResult.getIOObjects();
    }

    
    /** Returns true if and only if all inner operators accept their precessors' ouput
     *  as input. */
    public Class[] checkIO(Class[] input) throws IllegalInputException {
	for (int i = 0; i < getNumberOfOperators(); i++) {
	    Operator o = getOperator(i);
	    input = o.checkIO(new Class[] { ExampleSet.class });
	}
	return new Class[0];
    }


    public int getNumberOfSteps() {
	return 
	    (eSetList == null) ? 
	    1 :
	    eSetList.size()*getNumberOfChildrensSteps() + 1;
    }

}