transformation.mimlTOml.ArithmeticTransformation.java Source code

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Here is the source code for transformation.mimlTOml.ArithmeticTransformation.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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package transformation.mimlTOml;

import data.Bag;
import data.MIMLInstances;
import mulan.data.MultiLabelInstances;
import weka.core.DenseInstance;
import weka.core.Instance;
import weka.core.Instances;

/**
 * 
 * Class that performs an arithmetic transformation to convert a MIMLIntances
 * class to MultiLabelInstances. This arithmetic transformation transforms each
 * Bag into a single Instance being the value of each attribute the mean value
 * of the instances in the bag.
 * 
 * @author Ana I. Reyes Melero
 * @author Eva Gibaja
 * @author Amelia Zafra
 * @version 20170507
 *
 */
public class ArithmeticTransformation extends MIMLtoML {
    /**
     * Constructor.
     * 
     * @param dataset
     *            MIMLInstances dataset.
     * @throws Exception
     *             To be handled in an upper level.
     */
    public ArithmeticTransformation(MIMLInstances dataset) throws Exception {
        this.dataset = dataset;
        this.prepareTemplate();
        template.setRelationName(dataset.getDataSet().relationName() + "_arithmetic_transformation");
    }

    @Override
    public MultiLabelInstances transformDataset() throws Exception {
        Instances newData = new Instances(template);
        int labelIndices[] = dataset.getLabelIndices();
        Instance newInst = new DenseInstance(newData.numAttributes());
        newInst.setDataset(newData); // Sets the reference to the dataset

        // For all bags in the dataset
        double nBags = dataset.getNumBags();
        for (int i = 0; i < nBags; i++) {
            // retrieves a bag
            Bag bag = dataset.getBag(i);
            // sets the bagLabel
            newInst.setValue(0, bag.value(0));

            // retrieves instances (relational value) for each bag
            Instances instances = bag.getBagAsInstances();
            // for all attributes in bag
            for (int j = 0, attIdx = 1; j < instances.numAttributes(); j++, attIdx++) {
                double value = instances.meanOrMode(j);
                newInst.setValue(attIdx, value);
            }

            // inserts label information into the instance
            for (int j = 0; j < labelIndices.length; j++) {
                newInst.setValue(updatedLabelIndices[j], dataset.getBag(i).value(labelIndices[j]));
            }

            newData.add(newInst);
        }

        return new MultiLabelInstances(newData, dataset.getLabelsMetaData());
    }

    @Override
    public Instance transformInstance(Bag bag) throws Exception {

        int labelIndices[] = dataset.getLabelIndices();
        Instance newInst = new DenseInstance(template.numAttributes());

        // sets the bagLabel
        newInst.setDataset(bag.dataset()); // Sets the reference to the dataset
        newInst.setValue(0, bag.value(0));

        // retrieves instances (relational value)
        Instances instances = bag.getBagAsInstances();
        // For all attributes in bag
        for (int j = 0, attIdx = 1; j < instances.numAttributes(); j++, attIdx++) {
            double value = instances.meanOrMode(j);
            newInst.setValue(attIdx, value);
        }

        // Insert label information into the instance
        for (int j = 0; j < labelIndices.length; j++) {
            newInst.setValue(updatedLabelIndices[j], bag.value(labelIndices[j]));
        }

        return newInst;
    }

}