    001package net.sf.cpsolver.coursett.criteria;
    002
    003import java.util.Collection;
    004import java.util.HashSet;
    005import java.util.Set;
    006
    007import net.sf.cpsolver.coursett.constraint.DepartmentSpreadConstraint;
    008import net.sf.cpsolver.coursett.model.Lecture;
    009import net.sf.cpsolver.coursett.model.Placement;
    010import net.sf.cpsolver.ifs.util.DataProperties;
    011
    012/**
    013 * Department balancing penalty. This criterion tries to balance classes of each
    014 * department evenly. This means that for instance each department gets a fair
    015 * amount of unpopular times like early morning or late afternoon. This criterion
    016 * is counted by {@link DepartmentSpreadConstraint}.
    017 * <br>
    018 *
    019 * @version CourseTT 1.2 (University Course Timetabling)<br>
    020 *          Copyright (C) 2006 - 2011 Tomáš Müller<br>
    021 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    022 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    023 * <br>
    024 *          This library is free software; you can redistribute it and/or modify
    025 *          it under the terms of the GNU Lesser General Public License as
    026 *          published by the Free Software Foundation; either version 3 of the
    027 *          License, or (at your option) any later version. <br>
    028 * <br>
    029 *          This library is distributed in the hope that it will be useful, but
    030 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    031 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    032 *          Lesser General Public License for more details. <br>
    033 * <br>
    034 *          You should have received a copy of the GNU Lesser General Public
    035 *          License along with this library; if not see
    036 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    037 */
    038public class DepartmentBalancingPenalty extends SameSubpartBalancingPenalty {
    039
    040    @Override
    041    public double getWeightDefault(DataProperties config) {
    042        return 12.0 * config.getPropertyDouble("Comparator.DeptSpreadPenaltyWeight", 1.0);
    043    }
    044
    045    @Override
    046    public String getPlacementSelectionWeightName() {
    047        return "Placement.DeptSpreadPenaltyWeight";
    048    }
    049
    050    @Override
    051    public double getValue(Placement value, Set<Placement> conflicts) {
    052        return (value.variable().getDeptSpreadConstraint() == null ? 0.0 : value.variable().getDeptSpreadConstraint().getPenalty(value)) / 12.0;
    053    }
    054
    055    @Override
    056    public double getValue(Collection<Lecture> variables) {
    057        double ret = 0;
    058        Set<DepartmentSpreadConstraint> constraints = new HashSet<DepartmentSpreadConstraint>();
    059        for (Lecture lect: variables)
    060            if (lect.getDeptSpreadConstraint() != null && constraints.add(lect.getDeptSpreadConstraint()))
    061                ret += lect.getDeptSpreadConstraint().getPenalty();
    062        return ret / 12.0;
    063    }
    064}