    001package net.sf.cpsolver.coursett.criteria.additional;
    002
    003import java.util.Map;
    004import java.util.Set;
    005
    006import net.sf.cpsolver.coursett.criteria.TimetablingCriterion;
    007import net.sf.cpsolver.coursett.model.Lecture;
    008import net.sf.cpsolver.coursett.model.Placement;
    009import net.sf.cpsolver.coursett.model.RoomLocation;
    010import net.sf.cpsolver.ifs.solver.Solver;
    011import net.sf.cpsolver.ifs.util.DataProperties;
    012
    013/**
    014 * Cost for using room(s) that are too big. I.e., a difference between size of the assigned room and the size of the
    015 * smallest room in which the class can be placed {@link Lecture#minRoomSize()}.
    016 * <br><br>
    017 * A weight for room size penalty can be set by problem property Comparator.RoomSizeWeight.
    018 * <br><br>
    019 * The difference function can be made polynomial by using Comparator.RoomSizeFactor parameter
    020 * (defaults to 1.05). The value of this criteria is then cubed by the power of this room
    021 * size factor. This is to be able to favor a room swap between two classes at the same time,
    022 * in which a smaller class takes a smaller room. To do this, set Comparator.RoomSizeFactor to
    023 * a number bigger than one that is close to one (e.g., 1.05).
    024 *
    025 * <br>
    026 *
    027 * @version CourseTT 1.2 (University Course Timetabling)<br>
    028 *          Copyright (C) 2006 - 2013 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 RoomSizePenalty extends TimetablingCriterion {
    047    private double iRoomSizeFactor = 1.0;
    048
    049    @Override
    050    public boolean init(Solver<Lecture, Placement> solver) {
    051        super.init(solver);
    052        iRoomSizeFactor = solver.getProperties().getPropertyDouble("Comparator.RoomSizeFactor", 1.05);
    053        return true;
    054    }
    055
    056    @Override
    057    public double getWeightDefault(DataProperties config) {
    058        return config.getPropertyDouble("Comparator.RoomSizeWeight", 0.001);
    059    }
    060
    061    @Override
    062    public String getPlacementSelectionWeightName() {
    063        return "Placement.RoomSizeWeight";
    064    }
    065
    066    @Override
    067    public double getValue(Placement value, Set<Placement> conflicts) {
    068        if (value.variable().getNrRooms() <= 0) return 0.0;
    069        double size = 0;
    070        if (value.getRoomLocation() != null)
    071            size = value.getRoomLocation().getRoomSize();
    072        else if (value.getRoomLocations() != null) {
    073            for (RoomLocation room: value.getRoomLocations())
    074                size += room.getRoomSize();
    075            size /= value.getNrRooms();
    076        }
    077        double diff = size - value.variable().minRoomSize();
    078        return (diff < 0 ? 0 : Math.pow(diff, iRoomSizeFactor));
    079    }
    080
    081    @Override
    082    public void getInfo(Map<String, String> info) {
    083        if (getValue() != 0.0)
    084            info.put(getName(), sDoubleFormat.format(Math.pow(getValue() / getModel().nrAssignedVariables(), 1.0 / iRoomSizeFactor)));
    085    }
    086
    087}