    001package org.cpsolver.coursett.criteria;
    002
    003import java.util.Collection;
    004import java.util.HashSet;
    005import java.util.Set;
    006
    007import org.cpsolver.coursett.constraint.DepartmentSpreadConstraint;
    008import org.cpsolver.coursett.model.Lecture;
    009import org.cpsolver.coursett.model.Placement;
    010import org.cpsolver.ifs.assignment.Assignment;
    011import org.cpsolver.ifs.util.DataProperties;
    012
    013
    014/**
    015 * Department balancing penalty. This criterion tries to balance classes of each
    016 * department evenly. This means that for instance each department gets a fair
    017 * amount of unpopular times like early morning or late afternoon. This criterion
    018 * is counted by {@link DepartmentSpreadConstraint}.
    019 * <br>
    020 *
    021 * @author  Tomáš Müller
    022 * @version CourseTT 1.3 (University Course Timetabling)<br>
    023 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    024 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    025 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    026 * <br>
    027 *          This library is free software; you can redistribute it and/or modify
    028 *          it under the terms of the GNU Lesser General Public License as
    029 *          published by the Free Software Foundation; either version 3 of the
    030 *          License, or (at your option) any later version. <br>
    031 * <br>
    032 *          This library is distributed in the hope that it will be useful, but
    033 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    034 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    035 *          Lesser General Public License for more details. <br>
    036 * <br>
    037 *          You should have received a copy of the GNU Lesser General Public
    038 *          License along with this library; if not see
    039 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    040 */
    041public class DepartmentBalancingPenalty extends SameSubpartBalancingPenalty {
    042
    043    @Override
    044    public double getWeightDefault(DataProperties config) {
    045        return 12.0 * config.getPropertyDouble("Comparator.DeptSpreadPenaltyWeight", 1.0);
    046    }
    047
    048    @Override
    049    public String getPlacementSelectionWeightName() {
    050        return "Placement.DeptSpreadPenaltyWeight";
    051    }
    052
    053    @Override
    054    public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) {
    055        return (value.variable().getDeptSpreadConstraint() == null ? 0.0 : value.variable().getDeptSpreadConstraint().getPenalty(assignment, value)) / 12.0;
    056    }
    057
    058    @Override
    059    public double getValue(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
    060        double ret = 0;
    061        Set<DepartmentSpreadConstraint> constraints = new HashSet<DepartmentSpreadConstraint>();
    062        for (Lecture lect: variables)
    063            if (lect.getDeptSpreadConstraint() != null && constraints.add(lect.getDeptSpreadConstraint()))
    064                ret += lect.getDeptSpreadConstraint().getPenalty(assignment);
    065        return ret / 12.0;
    066    }
    067}