001    package net.sf.cpsolver.exam.criteria;
002    
003    import java.util.Map;
004    import java.util.Set;
005    
006    import net.sf.cpsolver.exam.model.Exam;
007    import net.sf.cpsolver.exam.model.ExamPlacement;
008    import net.sf.cpsolver.exam.model.ExamRoom;
009    import net.sf.cpsolver.exam.model.ExamRoomPlacement;
010    import net.sf.cpsolver.ifs.solver.Solver;
011    import 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 Tomas Muller<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     */
050    public 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    }