net.sf.jclal.classifier.MOAWrapper.java Source code

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Here is the source code for net.sf.jclal.classifier.MOAWrapper.java

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/*
 * 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.
 */

/**
 * Class that wrappers a class of MOA framework. 
 * 
 * @author Oscar Gabriel Reyes Pupo
 * @author Eduardo Perez Perdomo
 */

package net.sf.jclal.classifier;

import weka.classifiers.UpdateableClassifier;
import weka.core.Capabilities;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.RevisionUtils;
import weka.core.Utils;
import weka.core.Capabilities.Capability;

import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.ConfigurationRuntimeException;

import moa.classifiers.Classifier;
import net.sf.jclal.core.IConfigure;

public class MOAWrapper extends weka.classifiers.AbstractClassifier implements UpdateableClassifier, IConfigure {

    /** for serialization. */
    private static final long serialVersionUID = 2605797948130310166L;

    /** the actual MOA classifier to use for learning. */
    protected Classifier classifier;

    public MOAWrapper(Classifier classifier) {
        super();
        this.classifier = classifier;
    }

    public MOAWrapper() {
        super();
    }

    /**
     * Set the classifier
     * 
     * @param classifier
     *            The MOA classifier
     */
    public void setClassifier(Classifier classifier) {
        this.classifier = classifier;
    }

    /**
     * Returns the MOA classifier in use.
     *
     * @return the classifier in use
     */
    public Classifier getClassifier() {
        return classifier;
    }

    /**
     * Returns the Capabilities of this classifier. Maximally permissive
     * capabilities are allowed by default. MOA doesn't specify what
     *
     * @return the capabilities of this object
     * @see Capabilities
     */
    public Capabilities getCapabilities() {
        Capabilities result = new Capabilities(this);

        // attributes
        result.enable(Capability.NOMINAL_ATTRIBUTES);
        result.enable(Capability.NUMERIC_ATTRIBUTES);
        result.enable(Capability.MISSING_VALUES);

        // class
        result.enable(Capability.NOMINAL_CLASS);
        result.enable(Capability.MISSING_CLASS_VALUES);

        result.setMinimumNumberInstances(0);

        return result;
    }

    /**
     * {@inheritDoc}
     */
    public void buildClassifier(Instances data) throws Exception {

        getCapabilities().testWithFail(data);

        data = new Instances(data);
        data.deleteWithMissingClass();

        classifier.resetLearning();

        for (int i = 0; i < data.numInstances(); i++)
            updateClassifier(data.instance(i));

    }

    /**
     * {@inheritDoc}
     */
    public void updateClassifier(Instance instance) throws Exception {
        classifier.trainOnInstance(instance);
    }

    /**
     * {@inheritDoc}
     */
    public double[] distributionForInstance(Instance instance) throws Exception {
        double[] result;

        result = classifier.getVotesForInstance(instance);
        // ensure that the array has as many elements as there are
        // class values!
        if (result.length < instance.numClasses()) {
            double[] newResult = new double[instance.numClasses()];
            System.arraycopy(result, 0, newResult, 0, result.length);
            result = newResult;
        }

        try {
            Utils.normalize(result);
        } catch (Exception e) {
            result = new double[instance.numClasses()];
        }

        return result;
    }

    /**
     * Returns the revision string.
     *
     * @return the revision
     */
    public String getRevision() {
        return RevisionUtils.extract("$Revision$");

    }

    public String toString() {
        StringBuilder result;

        result = new StringBuilder();
        classifier.getDescription(result, 0);

        return result.toString();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void configure(Configuration configuration) {

        String classifierError = "classifier type= ";
        try {

            // classifier classname
            String classifierClassname = configuration.getString("classifier[@type]");

            classifierError += classifierClassname;

            // classifier class
            Class<? extends Classifier> classifierClass = (Class<? extends Classifier>) Class
                    .forName(classifierClassname);

            // Add this classifier
            setClassifier(classifierClass.newInstance());

        } catch (ClassNotFoundException e) {
            throw new ConfigurationRuntimeException("\nIllegal classifier classname: " + classifierError, e);
        } catch (InstantiationException e) {
            throw new ConfigurationRuntimeException("\nIllegal classifier classname: " + classifierError, e);
        } catch (IllegalAccessException e) {
            throw new ConfigurationRuntimeException("\nIllegal classifier classname: " + classifierError, e);
        }

    }

}