model.java

一个很好的LIBSVM的JAVA源码。对于要研究和改进SVM算法的学者。可以参考。来自数据挖掘工具YALE工具包。

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2001-2004
 *      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.operator.learner;

import edu.udo.cs.yale.operator.ResultObjectAdapter;
import edu.udo.cs.yale.operator.OperatorException;
import edu.udo.cs.yale.operator.Saveable;
import edu.udo.cs.yale.example.ExampleSet;
import edu.udo.cs.yale.example.Attribute;
import edu.udo.cs.yale.tools.LogService;
import edu.udo.cs.yale.tools.Tools;
import edu.udo.cs.yale.gui.SwingTools;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.awt.Component;
import javax.swing.JLabel;
import java.lang.reflect.Constructor;

/** Model is the superclass for all objects generated by learners. Learners can apply models to example sets 
 *  and thus predict labels.<br>
 *
 *  @author Ingo
 *  @version $Id: Model.java,v 2.19 2004/08/27 11:57:38 ingomierswa Exp $
 */
public abstract class Model extends ResultObjectAdapter implements Saveable {

    /** We remember the target attribute in order to be able to create predicted label
     *  attributes based on this type. It is declared transient since we handle 
     *  serialization of the attribute ourselves. */
    private transient Attribute labelAttribute;

    /** The predicted labels are the classifications. */
    public static final int  PREDICT_CLASSIFICATION = 0;
    /** The predicted labels are the confidence values. */
    public static final int  PREDICT_CONFIDENCE     = 1;

    /** All serializable subclasses must have a zero-argument constructor which is invoked during
     *  deserialization. */
    protected Model() { }

    /** All subclasses must pass a label {@link Attribute} to their superclass constructors. */
    public Model(Attribute label) {
	this.labelAttribute = label;
    }

    /** Applies the model by setting the predicted labels. */
    public abstract void apply(ExampleSet testSet) throws OperatorException;

    /** Writes the model to a stream. */
    public abstract void writeData(ObjectOutputStream out) throws IOException;

    public String toString() {
	return "Model (type " + Tools.classNameWOPackage(this.getClass()) + ") for label " + labelAttribute;
    }

    public void save(File file) throws IOException {
	writeModel(file);
    }

    /** Writes the model to a file by writing its class and calling writeModel(ObjectOutput). */
    public final void writeModel(File file) throws IOException {
	LogService.logMessage("Writing model to file '"+file+"'.", LogService.MINIMUM);
	ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(file));
	writeModel(out);
	out.close();
    }

    /** Writes the model to a file by writing its class and calling writeModel(ObjectOutput). */
    public final void writeModel(ObjectOutputStream out) throws IOException {
	out.writeUTF(getClass().getName());
	if (labelAttribute != null) {
	    out.writeUTF("label");
	    labelAttribute.writeType(out);
	} else {
	    out.writeUTF("nolabel");
	}
	writeData(out);
    }

    /** Reads the model from a file. */
    public static final Model readModel(File file) throws OperatorException, IOException {
	ObjectInputStream in = new ObjectInputStream(new FileInputStream(file));
	Model model = readModel(in);
	in.close();
	return model;
    }

    /** Reads the model from an ObjectInput. */
    public static final Model readModel(ObjectInputStream in) throws IOException {
	String className = in.readUTF();
	String labelString = in.readUTF();
	Attribute label = null;
	if (labelString.equals("label")) {
	    label = Attribute.readType(in);
	}
	Model model = null;
	try {
	    Class c = edu.udo.cs.yale.tools.Tools.classForName(className);
  	    if (!(Model.class.isAssignableFrom(c))) {
		throw new IOException("Model file does not contain a model (but "+c.getName()+")!");
  	    }
  	    if (SerializableModel.class.isAssignableFrom(c)) {
  		model = SerializableModel.readSerializableModel(in);
		model.labelAttribute = label;
  	    } else if (IOModel.class.isAssignableFrom(c)) {
		Constructor constructor = c.getConstructor(new Class[] { Attribute.class });
		model = (Model)constructor.newInstance(new Object[] { label });
		((IOModel)model).readData(in);
  	    } else {
  		throw new IOException("Don't know how to read a '"+className+"' model!");
  	    }
	} catch (ClassCastException e) {
	    throw new IOException("'"+className+"' is not a model!");
	} catch (ClassNotFoundException e) {
	    throw new IOException("Don't know anything about class '"+className+"'!");
	} catch (InstantiationException e) {
	    throw new IOException("Cannot instantiate '"+className+"': " + e);
	} catch (IllegalAccessException e) {
	    throw new IOException("Cannot instantiate '"+className+"': " + e);
	} catch (NoSuchMethodException e) {
	    throw new IOException("Cannot instantiate '"+className+"' (no one-argument constructor taking an Attribute): " + e);
	} catch (java.lang.reflect.InvocationTargetException e) {
	    throw new IOException("Cannot instantiate '"+className+"': Exception in constructor: " + e);
	} 
	return model;
    }


    /** Sets the type of the prediction. For binary classification tasks, the predicted label can
     *  either be the classification or the confidence (i.e. a real number).
     *  Currently, only the SVMLight makes use of this feature.
     *  @param type one out of PREDICT_CLASSIFICATIONS and PREDICT_CONFIDENCE */
    public void setPredictionType(int type) {
  	throw new UnsupportedOperationException(getClass().getName() + " does not support prediction of confidence.");
    }

    /** Returns true iff the given object has the same class. */
    public boolean equals(Object o) {
	return (o != null) && (this.getClass().equals(o.getClass()));
    }

    /** Returns the label for which this model was learned, i.e. the learning target attribute. */
    public Attribute getLabel() {
	return labelAttribute;
    }

    /** Creates a predicted label from the label of the given example set. 
     *  Invokes createPredictedLabel(exampleSet, null). */
    public Attribute createPredictedLabel(ExampleSet exampleSet) {
	return createPredictedLabel(exampleSet, null);
    }

    /** Creates a predicted label with the given name. If name is null, the name &quot;prediction(labelname)&quot;
     *  is used. */
    public Attribute createPredictedLabel(ExampleSet exampleSet, String name) {
  	Attribute predictedLabel = new Attribute(getLabel(), ExampleSet.PREDICTION_NAME);
	if (name != null) predictedLabel.setName(name);
  	exampleSet.getExampleTable().addAttribute(predictedLabel);
  	exampleSet.setPredictedLabel(predictedLabel);
	return predictedLabel;
    }
}