reciprocalvaluegenerator.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 reciprocal value of all input attributes. If the generator is bounded, 
 *  the values are bounded by the biggest and smallest possible values.
 *
 *  @author simon, ingo
 *  @version $Id: ReciprocalValueGenerator.java,v 2.3 2003/04/23 13:45:42 fischer Exp $
 */ 
public class ReciprocalValueGenerator extends FeatureGenerator {

    private static final double UPPER_BOUND = Double.MAX_VALUE;
    private static final double LOWER_BOUND = Double.MIN_VALUE;

    public static final String FUNCTION_NAMES[] = {"1/"};

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

    /** Indicates if this generator works with bounded values. */
    private boolean bounded = true;

    public ReciprocalValueGenerator(boolean bounded) {
	this.bounded = bounded;
    }

    public FeatureGenerator newInstance() {
	return new ReciprocalValueGenerator(bounded);
    }


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

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

    public void generate(DataRow data) throws GenerationException {
	try {
	    Attribute a = getArgument(0);
	    double o = data.get(a);

	    double r = 1 / o;

	    if (bounded) {
		if (r > UPPER_BOUND) {
		    LogService.logMessage(this.toString() + ": cannot operate on argument " + a +
					  ": result is out of bounds!", LogService.WARNING);
		    r = UPPER_BOUND;
		} else if (r < LOWER_BOUND) {
		    LogService.logMessage(this.toString() + ": cannot operate on argument " + a +
					  ": result is out of bounds!", LogService.WARNING);
		    r = LOWER_BOUND; 
		}
	    } else {
		if ((Double.isInfinite(r)) || (Double.isNaN(r))) {
		    throw new GenerationException(this.toString() + ": cannot operate on argument " 
						  + a + " (" + o + ") = "+r);
		}
	    }
	    
	    if (resultAttributes[0] != null)
	    data.set(resultAttributes[0], r);
	} catch (ArrayIndexOutOfBoundsException ex) {
  	    throw new GenerationException("a1:" + getArgument(0));
  	}
    }

    public void setFunction(String name) {
	for (int i = 0; i < FUNCTION_NAMES.length; i++) {
	    if (FUNCTION_NAMES[i].equals(name)) return;
	}
	LogService.logMessage("Illegal function name '"+name+"' for "+getClass().getName()+".", 
			      LogService.ERROR);
    }

    public String getFunction() {
	return FUNCTION_NAMES[0];
    }

}