/*
* 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.
*/
/*
* CopyWeight.java
* Copyright (C) 2009-2010 Aristotle University of Thessaloniki, Thessaloniki, Greece
*/
package mulan.transformations.multiclass;
import java.util.List;
import weka.core.Instance;
/**
* Class that implement the Copy-Weight transformation method
* @author Stavros
*/
public class CopyWeight extends Copy {
/**
* Transforms a multi-label instance to a list of single-label instances,
* one for each of the labels that annotate the instance, by copying the
* feature vector and attaching a weight equal to 1/(list size).
*
* @param instance a multi-label instance
* @return a list with the transformed single-label instances
*/
@Override
List<Instance> transformInstance(Instance instance) {
List<Instance> copy = super.transformInstance(instance);
for (Instance anInstance : copy) {
anInstance.setWeight(1.0 / copy.size());
}
return copy;
}
}