attributeweightedexampleset.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.Ontology;

import java.util.Iterator;
import java.util.Map;
import java.util.HashMap;

/** An implementation of ExampleSet that allows the weighting of the attributes. Weights can be queried by 
 *  the method {@link #getWeight(int)}.  */
public class AttributeWeightedExampleSet extends ExampleSetAdapter {

    private static class Weight {
	private double weight = 1.0d;
	private Weight(double weight) {
	    this.weight = weight;
	}
    }

    /** Flags indicating the weight of each attribute. */
    private Map weightMap = new HashMap();

    /** Clone constructor. */
    public AttributeWeightedExampleSet(AttributeWeightedExampleSet exampleSet) {
	super((ExampleSetAdapter)exampleSet);
	Iterator i = exampleSet.weightMap.keySet().iterator();
	while (i.hasNext()) {
	    String name = (String)i.next();
	    Weight weight = (Weight)exampleSet.weightMap.get(name);
	    this.weightMap.put(name, new Weight(weight.weight));
	}
    }
    
    /** Constructs a new AttributeWeightedExampleSet. Initially all examples are weighted with 1.0. */
    public AttributeWeightedExampleSet(ExampleSet exampleSet) {
	super(exampleSet);
	for (int i = 0; i < getNumberOfAttributes(); i++) {
	    weightMap.put(getAttribute(i).getName(), new Weight(1.0d));
	}
    }

    /** Returns the weight of the attribute. */
    public double getWeight(Attribute attribute) {
	Weight weight = (Weight)weightMap.get(attribute.getName());
	if (weight == null) {
	    throw new RuntimeException("Attribute " + attribute.getName() + " is not a regular attribute!");
	} else return weight.weight;
    }  

    /** Sets the weight of the attribute. */
    public void setWeight(Attribute attribute, double weightValue) {
	Weight weight = (Weight)weightMap.get(attribute.getName());
	weight.weight = weightValue;
	clearUserData();
    }  

    /** Returns the number of selected attributes. */
    public int getNumberOfUsedAttributes() {
	int counter = 0;
	for (int i = 0; i < getNumberOfAttributes(); i++) 
	    if (getWeight(i) != 0.0d) counter++;
	return counter;
    }

    // -------------------- wrapper methods --------------------

    /** Returns the weight of the attribute with the given index. */
    public double getWeight(int i) {
	return getWeight(getAttribute(i));
    }  

    /** Sets the weight of the attribute with the given index. */
    public void setWeight(int index, double weight) {
	setWeight(getAttribute(index), weight);
    }  

    /** Sets the weights of all attributes to 1.0. */
    public void selectAll() {
	setAll(1.0d);
    }

    /** Sets the weights of all attributes to 0.0. */
    public void deselectAll() {
	setAll(0.0d);
    }

    /** Sets all flags to the given value. */
    private void setAll(double weight) {
	for (int i = 0; i < getNumberOfAttributes(); i++) {
	    setWeight(getAttribute(i), weight);
	}
    }

    // -------------------- overridden methods --------------------

    public void addAttribute(Attribute attribute) {
	super.addAttribute(attribute);
	weightMap.put(attribute.getName(), new Weight(1.0d));
    }

    public void removeAttribute(Attribute attribute) {
	super.removeAttribute(attribute);
	weightMap.remove(attribute.getName());
    }

    public boolean equals(Object o) {
	if (!super.equals(o)) return false;
	if (!(o instanceof AttributeWeightedExampleSet)) return false;
	AttributeWeightedExampleSet es = (AttributeWeightedExampleSet)o;
	for (int i = 0; i < getNumberOfAttributes(); i++) {
	    if (es.getWeight(i) != this.getWeight(i))
		return false;
	}
	return true;
    }

    public String toString() {
	StringBuffer buffer = new StringBuffer(super.toString());
	buffer.append("\nWeights: ");
	for (int i = 0; i < getNumberOfAttributes(); i++) {
	    if (i != 0) buffer.append("\t");
	    if (i > 50) { buffer.append("..."); break; }
	    buffer.append(i + ": " + getWeight(i));
	}
	return buffer.toString();
    }

    // ---------------------------------------------------------

    /** Returns a new example set containing all used attributes. */
    public ExampleSet createExampleSet() {
	ExampleSet eSet = (ExampleSet)delegate.clone();
	for (int i = eSet.getNumberOfAttributes()-1; i >= 0; i--) {
	    Attribute attribute = eSet.getAttribute(i);
	    if (getWeight(attribute) == 0.0d) eSet.removeAttribute(attribute);
	    else if (getWeight(attribute) != 1.0d) {
		ExampleReader reader = eSet.getExampleReader();
		while (reader.hasNext()) {
		    Example example = reader.next();
		    example.setValue(attribute, example.getValue(attribute) * getWeight(attribute));
		}
	    }
	}
	return eSet;
    }
}