filteredexampleset.java

著名的开源仿真软件yale

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2002, 2003
 *      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;

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

/** Hides {@link Example}s that do not fulfill a given 
 *  {@link Condition}
 *
 *  @version $Id: FilteredExampleSet.java,v 2.3 2003/07/03 16:01:30 fischer Exp $
 */
public class FilteredExampleSet extends ExampleSetAdapter {

    private Condition condition;
    private int size = -1;

    public FilteredExampleSet(FilteredExampleSet exampleSet) {
	super(exampleSet);
	this.condition = exampleSet.condition;
    }

    public FilteredExampleSet(ExampleSet parent, Condition condition) {
	super(parent);
	if (condition == null) throw new IllegalArgumentException("Condition must not be null!");
	this.condition = condition;
    }

    public ExampleReader getExampleReader() {
	return new ConditionExampleReader(super.getExampleReader(), condition);
    }

    public int getSize() {
	if (size == -1) {
	    LogService.logMessage("FilteredExampleSet: Counting examples matching the condition.",
				  LogService.MINIMUM);
	    ExampleReader reader = getExampleReader();
	    size = 0;
	    while (reader.hasNext()) {
		size++;
		reader.next();
	    }
	}
	return size;
    }
}