br.unicamp.ic.recod.gpsi.measures.gpsiClusterDistortionScore.java Source code

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Here is the source code for br.unicamp.ic.recod.gpsi.measures.gpsiClusterDistortionScore.java

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package br.unicamp.ic.recod.gpsi.measures;

import org.apache.commons.math3.ml.distance.EuclideanDistance;
import org.apache.commons.math3.stat.descriptive.moment.VectorialMean;

/**
 *
 * @author ra163128
 */
public class gpsiClusterDistortionScore implements gpsiSampleSeparationScore {

    @Override
    public double score(double[][][] samples) {

        double score = 0.0;
        double[] centroid;
        double[][] vectors;
        int nClasses = samples.length, m = 0, m_i = 0, i;

        VectorialMean meanOperator;
        EuclideanDistance distance = new EuclideanDistance();

        for (int label = 0; label < samples.length; label++) {
            vectors = samples[label];
            meanOperator = new VectorialMean(vectors[0].length);
            for (i = 0; i < vectors.length; i++)
                meanOperator.increment(vectors[i]);
            centroid = meanOperator.getResult();

            m_i = vectors.length;
            for (i = 0; i < m_i; i++) {
                score += distance.compute(centroid, vectors[i]);
            }
            m += m_i;
        }

        if (score <= 1E-30)
            return Double.MAX_VALUE;

        return score / m;

    }

}