001package org.cpsolver.exam.criteria;
002
003import java.util.Map;
004import java.util.Set;
005
006import org.cpsolver.exam.model.Exam;
007import org.cpsolver.exam.model.ExamModel;
008import org.cpsolver.exam.model.ExamPlacement;
009import org.cpsolver.exam.model.ExamRoom;
010import org.cpsolver.exam.model.ExamRoomPlacement;
011import org.cpsolver.ifs.assignment.Assignment;
012import org.cpsolver.ifs.model.Model;
013import org.cpsolver.ifs.util.DataProperties;
014
015
016/**
017 * 
018 * Cost for using room(s) that are too big. I.e., a difference between total room size
019 * (computed using either {@link ExamRoom#getSize()} or {@link ExamRoom#getAltSize()} based
020 * on {@link Exam#hasAltSeating()}) and the number of students {@link Exam#getSize()}.
021 * <br><br>
022 * A weight for room size penalty can be set by problem
023 * property Exams.RoomSizeWeight, or in the input xml file, property
024 * roomSizeWeight).
025 * <br><br>
026 * The difference function can be made polynomial by using Exams.RoomSizeFactor parameter
027 * (defaults to 1.0). The value of this criteria is then cubed by the power of this room
028 * size factor. This is to be able to favor a room swap between two exams at the same period,
029 * in which a smaller exam takes a smaller room. To do this, set Exams.RoomSizeFactor to
030 * a number bigger than one that is close to one (e.g., 1.05).
031 * 
032 * <br>
033 * 
034 * @version ExamTT 1.3 (Examination Timetabling)<br>
035 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
036 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
037 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
038 * <br>
039 *          This library is free software; you can redistribute it and/or modify
040 *          it under the terms of the GNU Lesser General Public License as
041 *          published by the Free Software Foundation; either version 3 of the
042 *          License, or (at your option) any later version. <br>
043 * <br>
044 *          This library is distributed in the hope that it will be useful, but
045 *          WITHOUT ANY WARRANTY; without even the implied warranty of
046 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
047 *          Lesser General Public License for more details. <br>
048 * <br>
049 *          You should have received a copy of the GNU Lesser General Public
050 *          License along with this library; if not see
051 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
052 */
053public class RoomSizePenalty extends ExamCriterion {
054    private double iRoomSizeFactor = 1.0;
055    
056    @Override
057    public void configure(DataProperties properties) {   
058        super.configure(properties);
059        iRoomSizeFactor = properties.getPropertyDouble("Exams.RoomSizeFactor", 1.0);
060    }
061    
062    @Override
063    public void setModel(Model<Exam, ExamPlacement> model) {
064        super.setModel(model);
065        iRoomSizeFactor = ((ExamModel)model).getProperties().getPropertyDouble("Exams.RoomSizeFactor", 1.0);
066    }
067    
068    @Override
069    public String getWeightName() {
070        return "Exams.RoomSizeWeight";
071    }
072    
073    @Override
074    public String getXmlWeightName() {
075        return "roomSizeWeight";
076    }
077    
078    @Override
079    public double getWeightDefault(DataProperties config) {
080        return 0.0001;
081    }
082    
083    @Override
084    public void getXmlParameters(Map<String, String> params) {
085        params.put(getXmlWeightName(), String.valueOf(getWeight()));
086        params.put("roomSizeFactor", String.valueOf(iRoomSizeFactor));
087    }
088    
089    @Override
090    public void setXmlParameters(Map<String, String> params) {
091        try {
092            setWeight(Double.valueOf(params.get(getXmlWeightName())));
093        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
094        try {
095            iRoomSizeFactor = Double.valueOf(params.get("roomSizeFactor"));
096        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
097    }
098    
099    @Override
100    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
101        Exam exam = value.variable();
102        int size = 0;
103        if (value.getRoomPlacements() != null)
104            for (ExamRoomPlacement r : value.getRoomPlacements()) {
105                size += r.getSize(exam.hasAltSeating());
106            }
107        int diff = size - exam.getSize();
108        return (diff < 0 ? 0 : Math.pow(diff, iRoomSizeFactor));
109    }
110    
111    @Override
112    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
113        if (getValue(assignment) != 0.0) {
114            info.put(getName(), sDoubleFormat.format(getValue(assignment) / assignment.nrAssignedVariables()));
115        }
116    }
117
118    @Override
119    public String toString(Assignment<Exam, ExamPlacement> assignment) {
120        return "RSz:" + sDoubleFormat.format(getValue(assignment) / assignment.nrAssignedVariables());
121    }
122
123    @Override
124    public boolean isPeriodCriterion() { return false; }
125}