normalizationgenerator.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.generator;

import edu.udo.cs.yale.tools.Ontology;
import edu.udo.cs.yale.tools.LogService;
import edu.udo.cs.yale.example.Attribute;
import edu.udo.cs.yale.example.ExampleTable;
import edu.udo.cs.yale.example.Example;
import edu.udo.cs.yale.example.DataRow;

/** Creates the normalized value of all input attributes, i.e. calculates <br>
 *  value / (max - min)
 *
 *  @version $Id: NormalizationGenerator.java,v 2.3 2003/06/29 14:40:43 mierswa Exp $
 */ 
public class NormalizationGenerator extends FeatureGenerator {


    public static final String FUNCTION_NAME = "norm";

    /** Possible input attributes are numerical single values or interval values. */
    private static final Attribute[] INPUT_ATTR = { 
	new Attribute(Ontology.NUMERICAL, Ontology.NON_SERIES),
    };

    public FeatureGenerator newInstance() {
	return new NormalizationGenerator();
    }

    public Attribute[] getInputAttributes() {
	return INPUT_ATTR;
    }

    public Attribute[] getOutputAttributes(ExampleTable input) {
	Attribute a = getArgument(0);
	Attribute ao = new Attribute(Ontology.NUMERICAL, a.getBlockType(),
				     FUNCTION_NAME, new Attribute[] {a}, false,
				     a.getBlockNr(), null);
	return new Attribute[] { ao };
    }

    public void generate(DataRow data) throws GenerationException {
	try {
	    Attribute a = getArgument(0);
	    double o = data.get(a);
	    // if max = min, all values are the same and are normalized to 0.0
	    double n = a.getMaximum() - a.getMinimum();
	    double r = 0.0d;
	    if (n != 0.0d)
		r = (o - a.getMinimum()) / n;
	    
	    if (resultAttributes[0] != null)
		data.set(resultAttributes[0], r);
	} catch (ArrayIndexOutOfBoundsException ex) {
  	    throw new GenerationException("a1:" + getArgument(0));
  	}
    }

    public void setFunction(String name) {
	if (!FUNCTION_NAME.equals(name))
	    LogService.logMessage("Illegal function name '"+name+"' for "+getClass().getName()+".", 
				  LogService.ERROR);
    }

    public String getFunction() {
	return FUNCTION_NAME;
    }

}