    001package net.sf.cpsolver.exam.criteria.additional;
    002
    003import java.util.Map;
    004import java.util.Set;
    005
    006import net.sf.cpsolver.exam.criteria.ExamCriterion;
    007import net.sf.cpsolver.exam.model.ExamPlacement;
    008import net.sf.cpsolver.exam.model.ExamRoomPlacement;
    009import net.sf.cpsolver.ifs.util.DataProperties;
    010
    011/**
    012 * Experimental criterion measuring average distance (in meters) to the
    013 * strongly preferred room (or rooms) of the examination. The idea is to
    014 * prefer rooms that are close to the strongly preference room (if there is
    015 * a strongly preferred room but it is not available).
    016 * <br><br>
    017 * A weight of the average distance between the assigned room(s) and the
    018 * strongly preferred room or rooms can be set using
    019 * Exams.DistanceToStronglyPreferredRoomWeight property.
    020 * <br><br>
    021 * To enable this criterion add this class name to Exams.AdditionalCriteria
    022 * parameter. For instance:<br>
    023 * Exams.AdditionalCriteria=net.sf.cpsolver.exam.criteria.additional.DistanceToStronglyPreferredRoom
    024 *
    025 * <br>
    026 *
    027 * @version ExamTT 1.2 (Examination Timetabling)<br>
    028 *          Copyright (C) 2008 - 2012 Tomáš Müller<br>
    029 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    030 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    031 * <br>
    032 *          This library is free software; you can redistribute it and/or modify
    033 *          it under the terms of the GNU Lesser General Public License as
    034 *          published by the Free Software Foundation; either version 3 of the
    035 *          License, or (at your option) any later version. <br>
    036 * <br>
    037 *          This library is distributed in the hope that it will be useful, but
    038 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    039 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    040 *          Lesser General Public License for more details. <br>
    041 * <br>
    042 *          You should have received a copy of the GNU Lesser General Public
    043 *          License along with this library; if not see
    044 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    045 */
    046public class DistanceToStronglyPreferredRoom extends ExamCriterion {
    047
    048    @Override
    049    public String getWeightName() {
    050        return "Exams.DistanceToStronglyPreferredRoomWeight";
    051    }
    052
    053    @Override
    054    public String getXmlWeightName() {
    055        return "distanceToStronglyPreferredRoomWeight";
    056    }
    057
    058    @Override
    059    public double getWeightDefault(DataProperties config) {
    060        return 0.001;
    061    }
    062
    063    @Override
    064    public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
    065        Average ret = new Average();
    066        for (ExamRoomPlacement assigned: value.getRoomPlacements()) {
    067            for (ExamRoomPlacement preferred: value.variable().getRoomPlacements()) {
    068                if (preferred.getPenalty() < -2) // strongly preferred
    069                    ret.add(assigned.getDistanceInMeters(preferred));
    070            }
    071        }
    072        return ret.average();
    073    }
    074
    075    @Override
    076    public String toString() {
    077        return "@D:" + sDoubleFormat.format(getValue() / getModel().assignedVariables().size());
    078    }
    079
    080    @Override
    081    public double[] getBounds() {
    082        return new double[] { 0.0, 0.0 };
    083    }
    084
    085    @Override
    086    public void getInfo(Map<String, String> info) {
    087        if (getValue() > 0.0)
    088            info.put(getName(), sDoubleFormat.format(getValue() / getModel().assignedVariables().size()) + " m");
    089    }
    090
    091    private static class Average {
    092        double iValue = 0.0;
    093        int iCount = 0;
    094
    095        private void add(double value) {
    096            iValue += value; iCount ++;
    097        }
    098
    099        public double average() {
    100            return (iCount == 0 ? 0.0 : iValue / iCount);
    101        }
    102    }
    103
    104}