001 package net.sf.cpsolver.coursett.criteria.additional;
002
003 import java.util.Map;
004 import java.util.Set;
005
006 import net.sf.cpsolver.coursett.criteria.TimetablingCriterion;
007 import net.sf.cpsolver.coursett.model.Lecture;
008 import net.sf.cpsolver.coursett.model.Placement;
009 import net.sf.cpsolver.coursett.model.RoomLocation;
010 import net.sf.cpsolver.ifs.solver.Solver;
011 import 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 Tomas Muller<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 */
046 public 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 }