    001package net.sf.cpsolver.exam.criteria;
    002
    003import java.util.Map;
    004import java.util.Set;
    005
    006import net.sf.cpsolver.exam.model.Exam;
    007import net.sf.cpsolver.exam.model.ExamPlacement;
    008import net.sf.cpsolver.exam.model.ExamRoom;
    009import net.sf.cpsolver.exam.model.ExamRoomPlacement;
    010import net.sf.cpsolver.ifs.solver.Solver;
    011import net.sf.cpsolver.ifs.util.DataProperties;
    012
    013/**
    014 *
    015 * Cost for using room(s) that are too big. I.e., a difference between total room size
    016 * (computed using either {@link ExamRoom#getSize()} or {@link ExamRoom#getAltSize()} based
    017 * on {@link Exam#hasAltSeating()}) and the number of students {@link Exam#getSize()}.
    018 * <br><br>
    019 * A weight for room size penalty can be set by problem
    020 * property Exams.RoomSizeWeight, or in the input xml file, property
    021 * roomSizeWeight).
    022 * <br><br>
    023 * The difference function can be made polynomial by using Exams.RoomSizeFactor parameter
    024 * (defaults to 1.0). The value of this criteria is then cubed by the power of this room
    025 * size factor. This is to be able to favor a room swap between two exams at the same period,
    026 * in which a smaller exam takes a smaller room. To do this, set Exams.RoomSizeFactor to
    027 * a number bigger than one that is close to one (e.g., 1.05).
    028 *
    029 * <br>
    030 *
    031 * @version ExamTT 1.2 (Examination Timetabling)<br>
    032 *          Copyright (C) 2008 - 2012 Tomáš Müller<br>
    033 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    034 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    035 * <br>
    036 *          This library is free software; you can redistribute it and/or modify
    037 *          it under the terms of the GNU Lesser General Public License as
    038 *          published by the Free Software Foundation; either version 3 of the
    039 *          License, or (at your option) any later version. <br>
    040 * <br>
    041 *          This library is distributed in the hope that it will be useful, but
    042 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    043 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    044 *          Lesser General Public License for more details. <br>
    045 * <br>
    046 *          You should have received a copy of the GNU Lesser General Public
    047 *          License along with this library; if not see
    048 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    049 */
    050public class RoomSizePenalty extends ExamCriterion {
    051    private double iRoomSizeFactor = 1.0;
    052
    053    @Override
    054    public boolean init(Solver<Exam, ExamPlacement> solver) {
    055        iRoomSizeFactor = solver.getProperties().getPropertyDouble("Exams.RoomSizeFactor", 1.0);
    056        return super.init(solver);
    057    }
    058
    059    @Override
    060    public String getWeightName() {
    061        return "Exams.RoomSizeWeight";
    062    }
    063
    064    @Override
    065    public String getXmlWeightName() {
    066        return "roomSizeWeight";
    067    }
    068
    069    @Override
    070    public double getWeightDefault(DataProperties config) {
    071        return 0.0001;
    072    }
    073
    074    @Override
    075    public void getXmlParameters(Map<String, String> params) {
    076        params.put(getXmlWeightName(), String.valueOf(getWeight()));
    077        params.put("roomSizeFactor", String.valueOf(iRoomSizeFactor));
    078    }
    079
    080    @Override
    081    public void setXmlParameters(Map<String, String> params) {
    082        try {
    083            setWeight(Double.valueOf(params.get(getXmlWeightName())));
    084        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
    085        try {
    086            iRoomSizeFactor = Double.valueOf(params.get("roomSizeFactor"));
    087        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
    088    }
    089
    090    @Override
    091    public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
    092        Exam exam = value.variable();
    093        int size = 0;
    094        if (value.getRoomPlacements() != null)
    095            for (ExamRoomPlacement r : value.getRoomPlacements()) {
    096                size += r.getSize(exam.hasAltSeating());
    097            }
    098        int diff = size - exam.getSize();
    099        return (diff < 0 ? 0 : Math.pow(diff, iRoomSizeFactor));
    100    }
    101
    102    @Override
    103    public void getInfo(Map<String, String> info) {
    104        if (getValue() != 0.0) {
    105            info.put(getName(), sDoubleFormat.format(getValue() / getModel().nrAssignedVariables()));
    106        }
    107    }
    108
    109    @Override
    110    public String toString() {
    111        return "RSz:" + sDoubleFormat.format(getValue() / getModel().nrAssignedVariables());
    112    }
    113
    114    @Override
    115    public boolean isPeriodCriterion() { return false; }
    116}