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 * @author  Tomáš Müller
035 * @version ExamTT 1.3 (Examination Timetabling)<br>
036 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
037 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
038 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
039 * <br>
040 *          This library is free software; you can redistribute it and/or modify
041 *          it under the terms of the GNU Lesser General Public License as
042 *          published by the Free Software Foundation; either version 3 of the
043 *          License, or (at your option) any later version. <br>
044 * <br>
045 *          This library is distributed in the hope that it will be useful, but
046 *          WITHOUT ANY WARRANTY; without even the implied warranty of
047 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
048 *          Lesser General Public License for more details. <br>
049 * <br>
050 *          You should have received a copy of the GNU Lesser General Public
051 *          License along with this library; if not see
052 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
053 */
054public class RoomSizePenalty extends ExamCriterion {
055    private double iRoomSizeFactor = 1.0;
056    
057    @Override
058    public void configure(DataProperties properties) {   
059        super.configure(properties);
060        iRoomSizeFactor = properties.getPropertyDouble("Exams.RoomSizeFactor", 1.0);
061    }
062    
063    @Override
064    public void setModel(Model<Exam, ExamPlacement> model) {
065        super.setModel(model);
066        iRoomSizeFactor = ((ExamModel)model).getProperties().getPropertyDouble("Exams.RoomSizeFactor", 1.0);
067    }
068    
069    @Override
070    public String getWeightName() {
071        return "Exams.RoomSizeWeight";
072    }
073    
074    @Override
075    public String getXmlWeightName() {
076        return "roomSizeWeight";
077    }
078    
079    @Override
080    public double getWeightDefault(DataProperties config) {
081        return 0.0001;
082    }
083    
084    @Override
085    public void getXmlParameters(Map<String, String> params) {
086        params.put(getXmlWeightName(), String.valueOf(getWeight()));
087        params.put("roomSizeFactor", String.valueOf(iRoomSizeFactor));
088    }
089    
090    @Override
091    public void setXmlParameters(Map<String, String> params) {
092        try {
093            setWeight(Double.valueOf(params.get(getXmlWeightName())));
094        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
095        try {
096            iRoomSizeFactor = Double.valueOf(params.get("roomSizeFactor"));
097        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
098    }
099    
100    @Override
101    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
102        Exam exam = value.variable();
103        int size = 0;
104        if (value.getRoomPlacements() != null)
105            for (ExamRoomPlacement r : value.getRoomPlacements()) {
106                size += r.getSize(exam.hasAltSeating());
107            }
108        int diff = size - exam.getSize();
109        return (diff < 0 ? 0 : Math.pow(diff, iRoomSizeFactor));
110    }
111    
112    @Override
113    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
114        if (getValue(assignment) != 0.0) {
115            info.put(getName(), sDoubleFormat.format(getValue(assignment) / assignment.nrAssignedVariables()));
116        }
117    }
118
119    @Override
120    public String toString(Assignment<Exam, ExamPlacement> assignment) {
121        return "RSz:" + sDoubleFormat.format(getValue(assignment) / assignment.nrAssignedVariables());
122    }
123
124    @Override
125    public boolean isPeriodCriterion() { return false; }
126}