mlda.attributes.MeanEntropiesNominalAttributes.java Source code

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Here is the source code for mlda.attributes.MeanEntropiesNominalAttributes.java

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/*
 * This file is part of the MLDA.
 *
 * (c)  Jose Maria Moyano Murillo
 *      Eva Lucrecia Gibaja Galindo
 *      Sebastian Ventura Soto <sventura@uco.es>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

package mlda.attributes;

import mlda.base.MLDataMetric;
import mlda.util.Utils;
import mulan.data.MultiLabelInstances;
import weka.core.AttributeStats;
import weka.core.Instances;

/**
* Class implementing the Mean of entropies of nominal attributes
*
* @author Jose Maria Moyano Murillo
*/
public class MeanEntropiesNominalAttributes extends MLDataMetric {

    /**
     * Constructor
     */
    public MeanEntropiesNominalAttributes() {
        super("Mean of entropies of nominal attributes");
    }

    /**
     * Calculate metric value
     * 
     * @param mlData Multi-label dataset to which calculate the metric
     * @return Value of the metric
     */
    public double calculate(MultiLabelInstances mlData) {
        double mean = 0.0;

        Instances instances = mlData.getDataSet();

        int countNominal = 0;
        int[] featureIndices = mlData.getFeatureIndices();

        for (int fIndex : featureIndices) {
            AttributeStats attStats = instances.attributeStats(fIndex);
            if (attStats.nominalCounts != null) {
                countNominal++;
                mean += Utils.entropy(attStats.nominalCounts);
            }
        }

        mean = mean / countNominal;

        this.value = mean;
        return value;
    }

}