/*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* MultiClassLearner.java
* Copyright (C) 2009-2010 Aristotle University of Thessaloniki, Thessaloniki, Greece
*/
package mulan.classifier.transformation;
import mulan.classifier.MultiLabelOutput;
import mulan.data.MultiLabelInstances;
import mulan.transformations.RemoveAllLabels;
import mulan.transformations.multiclass.MultiClassTransformation;
import weka.classifiers.Classifier;
import weka.core.Instance;
import weka.core.Instances;
/**
* @author Stavros Mpakirtzoglou
* @author Grigorios Tsoumakas
* @version $Revision: 0.05$
*/
public class MultiClassLearner extends TransformationBasedMultiLabelLearner {
private Instances header;
private MultiClassTransformation transformation;
/**
* Initializes learner
*
* @param baseClassifier the base single-label classification algorithm
* @param dt the {@link MultiClassTransformation} to use
*/
public MultiClassLearner(Classifier baseClassifier, MultiClassTransformation dt) {
super(baseClassifier);
transformation = dt;
}
protected void buildInternal(MultiLabelInstances train) throws Exception {
debug("Transforming the training set");
Instances meta = transformation.transformInstances(train);
baseClassifier.buildClassifier(meta);
header = new Instances(meta, 0);
}
protected MultiLabelOutput makePredictionInternal(Instance instance) throws Exception {
//delete labels
instance = RemoveAllLabels.transformInstance(instance, labelIndices);
instance.setDataset(null);
instance.insertAttributeAt(instance.numAttributes());
instance.setDataset(header);
double[] distribution = baseClassifier.distributionForInstance(instance);
MultiLabelOutput mlo = new MultiLabelOutput(MultiLabelOutput.ranksFromValues(distribution));
return mlo;
}
}