/*
* MajorityClass.java
* Copyright (C) 2007 University of Waikato, Hamilton, New Zealand
* @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
*
* 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.
*/
package tr.gov.ulakbim.jDenetX.classifiers;
import tr.gov.ulakbim.jDenetX.core.DoubleVector;
import tr.gov.ulakbim.jDenetX.core.Measurement;
import tr.gov.ulakbim.jDenetX.core.StringUtils;
import weka.core.Instance;
public class MajorityClass extends AbstractClassifier {
private static final long serialVersionUID = 1L;
@SuppressWarnings("hiding")
public static final String classifierPurposeString = "Majority class classifier: always predicts the class that has been observed most frequently the in the training data.";
protected DoubleVector observedClassDistribution;
@Override
public void resetLearningImpl() {
this.observedClassDistribution = new DoubleVector();
}
@Override
public void trainOnInstanceImpl(Instance inst) {
this.observedClassDistribution.addToValue((int) inst.classValue(), inst
.weight());
}
public double[] getVotesForInstance(Instance i) {
return this.observedClassDistribution.getArrayCopy();
}
@Override
protected Measurement[] getModelMeasurementsImpl() {
Measurement[] measurement = null;
return null;
}
@Override
public void getModelDescription(StringBuilder out, int indent) {
StringUtils.appendIndented(out, indent, "Predicted majority ");
out.append(getClassNameString());
out.append(" = ");
out.append(getClassLabelString(this.observedClassDistribution
.maxIndex()));
StringUtils.appendNewline(out);
for (int i = 0; i < this.observedClassDistribution.numValues(); i++) {
StringUtils.appendIndented(out, indent, "Observed weight of ");
out.append(getClassLabelString(i));
out.append(": ");
out.append(this.observedClassDistribution.getValue(i));
StringUtils.appendNewline(out);
}
}
public boolean isRandomizable() {
return false;
}
}