sparsemapdatarow.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 java.util.Map;
import java.util.HashMap;

/** Implementation of DataRow that is backed by a HashMap. 
 *  @version $Id: SparseMapDataRow.java,v 2.4 2003/06/03 20:49:00 fischer Exp $ 
 */
public class SparseMapDataRow implements DataRow {

    private Map data = new HashMap();

    public double get(Attribute attribute) {
	Double value = (Double)data.get(new Integer(attribute.getIndex()));
	if (value != null) return value.doubleValue();
	else return attribute.isNominal() ? Attribute.FIRST_CLASS_INDEX : 0.0;
    }

    public void set(Attribute attribute, double value) {
	int index = attribute.getIndex();
	double deflt = attribute.isNominal() ? Attribute.FIRST_CLASS_INDEX : 0.0;
	if (value == deflt) data.remove(new Integer(index));
	else data.put(new Integer(index), new Double(value));
    }

    public void ensureNumberOfColumns(int numberOfColumns) {}

}