BubbleFitnessFunctor.java example

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activityinfo-master
package org.activityinfo.server.report.generator.map.cluster.genetic;

/*
 * #%L
 * ActivityInfo Server
 * %%
 * Copyright (C) 2009 - 2013 UNICEF
 * %%
 * 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 3 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, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #L%
 */

import org.activityinfo.server.report.generator.map.CircleMath;
import org.activityinfo.server.report.generator.map.cluster.Cluster;

import java.util.List;

/**
 * Scores the fitness of a circle clustering solution, awarding points for more
 * bubbles, and penalizing solutions in which bubbles overlap.
 */
public class BubbleFitnessFunctor implements FitnessFunctor {

    @Override
    public double score(List<Cluster> clusters) {

        double score = 0;
        for (int i = 0; i != clusters.size(); ++i) {

            // award a score for the presence of this cluster
            // (all things equal, the more markers the better)
            score += CircleMath.area(clusters.get(i).getRadius());

            // penalize conflicts with other clusters
            for (int j = i + 1; j != clusters.size(); ++j) {

                score -= 4.0 * CircleMath.intersectionArea(clusters.get(i).getPoint(),
                        clusters.get(j).getPoint(),
                        clusters.get(i).getRadius(),
                        clusters.get(j).getRadius());
            }
        }
        return score;
    }
}