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 }