001    package net.sf.cpsolver.exam.criteria;
002    
003    import java.util.Set;
004    
005    import net.sf.cpsolver.exam.model.Exam;
006    import net.sf.cpsolver.exam.model.ExamPlacement;
007    import net.sf.cpsolver.exam.model.ExamRoomPlacement;
008    import net.sf.cpsolver.ifs.util.DataProperties;
009    
010    /**
011     * Room perturbation penalty. I.e., number of assigned rooms different from
012     * initial. Only applicable when {@link PerturbationPenalty#isMPP()} is true (minimal
013     * perturbation problem).
014     * <br><br>
015     * A weight of room perturbations (i.e., a penalty for
016     * an assignment of an exam to a room different from the initial one) can be
017     * set by problem property Exams.RoomPerturbationWeight, or in the input xml
018     * file, property roomPerturbationWeight).
019     * 
020     * <br>
021     * 
022     * @version ExamTT 1.2 (Examination Timetabling)<br>
023     *          Copyright (C) 2008 - 2012 Tomas Muller<br>
024     *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
025     *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
026     * <br>
027     *          This library is free software; you can redistribute it and/or modify
028     *          it under the terms of the GNU Lesser General Public License as
029     *          published by the Free Software Foundation; either version 3 of the
030     *          License, or (at your option) any later version. <br>
031     * <br>
032     *          This library is distributed in the hope that it will be useful, but
033     *          WITHOUT ANY WARRANTY; without even the implied warranty of
034     *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
035     *          Lesser General Public License for more details. <br>
036     * <br>
037     *          You should have received a copy of the GNU Lesser General Public
038     *          License along with this library; if not see
039     *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
040     */
041    public class RoomPerturbationPenalty extends PerturbationPenalty {
042        
043        @Override
044        public String getWeightName() {
045            return "Exams.RoomPerturbationWeight";
046        }
047        
048        @Override
049        public String getXmlWeightName() {
050            return "roomPerturbationWeight";
051        }
052        
053        @Override
054        public double getWeightDefault(DataProperties config) {
055            return 0.01;
056        }
057    
058        @Override
059        public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
060            if (!isMPP()) return 0;
061            Exam exam = value.variable();
062            ExamPlacement initial = exam.getInitialAssignment();
063            if (initial == null) return 0;
064            int penalty = 0;
065            if (value.getRoomPlacements() != null)
066                for (ExamRoomPlacement rp : value.getRoomPlacements()) {
067                    if (initial.getRoomPlacements() == null || !initial.getRoomPlacements().contains(rp))
068                        penalty++;
069                }
070            return penalty;
071        }
072    
073    
074        @Override
075        public String toString() {
076            return (isMPP() ? "IRP:" + sDoubleFormat.format(getValue()) : "");
077        }
078    
079        @Override
080        public boolean isPeriodCriterion() { return false; }
081    }