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


/** This class is a very simple implementation of a FeatureGenerator. It has two numerical input
 *  attributes and one output attribute. Depending on the mode specified in the constructor the
 *  result will be the sum, difference, product or quotient. The four modes are numered from 0 to 3
 *  int this order.
 *
 *  @author simon, ingo
 *  @version $Id: BasicArithmeticOperationGenerator.java,v 2.5 2003/09/04 14:39:49 fischer Exp $
 */
public class BasicArithmeticOperationGenerator extends FeatureGenerator {  

    private static final Attribute[] INPUT_ATTR = { new Attribute(Ontology.NUMERICAL, Ontology.SINGLE_VALUE),
						    new Attribute(Ontology.NUMERICAL, Ontology.SINGLE_VALUE) };

    private static final int[] VALUE_TYPES = {Ontology.NUMERICAL,    Ontology.NUMERICAL};
    private static final int[] BLOCK_TYPES = {Ontology.SINGLE_VALUE, Ontology.SINGLE_VALUE};
    private static final int[] RESULT_VALUE_TYPE = { Ontology.NUMERICAL };
    private static final int[] RESULT_BLOCK_TYPE = { Ontology.SINGLE_VALUE };

    public static final String[] FUNCTION_NAMES = { "+", "-", "*", "/" };

    private int mode;
    private boolean bounded;

    public BasicArithmeticOperationGenerator() {

    }

    public BasicArithmeticOperationGenerator(int mode) {
	this(mode, false);
    }

    public BasicArithmeticOperationGenerator(int mode, boolean bounded) {
	this.mode = mode;
	this.bounded = bounded;
    }

    public FeatureGenerator newInstance() {
	return new BasicArithmeticOperationGenerator(mode, bounded);
    }

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

    public Attribute[] getOutputAttributes(ExampleTable input) {
	Attribute a1 = getArgument(0);
	Attribute a2 = getArgument(1);
        if ((mode == 0) ||
	    (mode == 2) ||
	    !a1.getConstructionDescription().equals(a2.getConstructionDescription())) { 
	    String op = FUNCTION_NAMES[mode];
	    Attribute ao = new Attribute(Ontology.NUMERICAL, Ontology.SINGLE_VALUE,
					 op, new Attribute[] { a1, a2 }, true,
					 input.getNextFreeBlockNr(),
					 null);
	    return new Attribute[] { ao };
	}
        else {
	    LogService.logMessage("Identical attribute descriptions. No attribute is constructed.", 
				  LogService.WARNING);
	    return new Attribute[] {};
        }
    }


    public void generate(DataRow data) throws GenerationException {
	try {
  	    Attribute a0 = getArgument(0);
  	    Attribute a1 = getArgument(1);
	    double o1 = data.get(a0);
	    double o2 = data.get(a1);
	    double r = 0;
	    switch (mode) {
	    case 0: r = o1 + o2; break;
	    case 1: r = o1 - o2; break;
	    case 2: r = o1 * o2; break;
	    case 3: r = o1 / o2; break;
	    }

	    if (bounded) {
                if (r >= Double.MAX_VALUE) {
		    LogService.logMessage(this.toString()+": cannot operate on arguments " + a0 + " and " + a1 +
					  ": result is out of bounds!", LogService.WARNING);
                    r = Double.MAX_VALUE;
		} else if ((0 < r) && (r < Double.MIN_VALUE)) {
		    LogService.logMessage(this.toString()+": cannot operate on arguments " + a0 + " and " + a1 +
					  ": result is out of bounds!", LogService.WARNING);
		    r = Double.MIN_VALUE;
		} else if ((0 > r) && (r > -Double.MIN_VALUE)) {
		    LogService.logMessage(this.toString()+": cannot operate on arguments " + a0 + " and " + a1 +
					  ": result is out of bounds!", LogService.WARNING);
		    r = - Double.MIN_VALUE;
  		} else if (r <= -Double.MAX_VALUE) {
		    LogService.logMessage(this.toString()+": cannot operate on arguments " + a0 + " and " + a1 +
					  ": result is out of bounds!", LogService.WARNING);
                    r = -Double.MAX_VALUE;
		} else if (Double.isNaN(r)) {
		    LogService.logMessage(this.toString()+": cannot operate on arguments " + a0 + " and " + a1 +
					  ": result is out of bounds!", LogService.WARNING);
		    r = 0;
		}
	    } else {
		if ((Double.isInfinite(r)) || (Double.isNaN(r))) {
		    throw new GenerationException(this.toString() + ": cannot operate on arguments "
						  + a0 + " (" + o1 + ") and "
						  + a1 + " (" + o2 + ") = "+r);
		}
	    }

	    if (resultAttributes[0] != null)
		data.set(resultAttributes[0], r);
	} catch (ArrayIndexOutOfBoundsException ex) {
  	    throw new GenerationException("a1:" + getArgument(0) + " a2: " + getArgument(1));
  	}
    }

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

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

    public String toString() {
	String s = "Basic arithmetic operation (";
	if ((resultAttributes != null) && 
	    (resultAttributes[0] != null))
	    s += resultAttributes[0].getName()+":=";
	if (argumentsSet()) s+=getArgument(0).getName() + " ";
	switch (mode) {
	  case 0: s += "+"; break;
	  case 1: s += "-"; break;
	  case 2: s += "*"; break;
	  case 3: s += "/"; break;
	}
	if (argumentsSet()) s+=" " + getArgument(1).getName();
	s += ")";
	return s;
    }

    public boolean equals(Object o) {
	return (super.equals(o) && (this.mode == ((BasicArithmeticOperationGenerator)o).mode));
    }
}