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.ExamPlacement;
008import org.cpsolver.ifs.assignment.Assignment;
009import org.cpsolver.ifs.util.DataProperties;
010
011
012/**
013 * Perturbation penalty. I.e., penalty for using a different examination period than
014 * initial. Only applicable when {@link PerturbationPenalty#isMPP()} is true (minimal
015 * perturbation problem).
016 * <br><br>
017 * A weight of perturbations (i.e., a penalty for an
018 * assignment of an exam to a place different from the initial one) can be
019 * set by problem property Exams.PerturbationWeight, or in the input xml
020 * file, property perturbationWeight).
021 * 
022 * <br>
023 * 
024 * @author  Tomáš Müller
025 * @version ExamTT 1.3 (Examination Timetabling)<br>
026 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
027 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
028 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
029 * <br>
030 *          This library is free software; you can redistribute it and/or modify
031 *          it under the terms of the GNU Lesser General Public License as
032 *          published by the Free Software Foundation; either version 3 of the
033 *          License, or (at your option) any later version. <br>
034 * <br>
035 *          This library is distributed in the hope that it will be useful, but
036 *          WITHOUT ANY WARRANTY; without even the implied warranty of
037 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
038 *          Lesser General Public License for more details. <br>
039 * <br>
040 *          You should have received a copy of the GNU Lesser General Public
041 *          License along with this library; if not see
042 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
043 */
044public class PerturbationPenalty extends ExamCriterion {
045    private boolean iMPP = false;
046    
047    @Override
048    public void configure(DataProperties properties) {   
049        super.configure(properties);
050        iMPP = properties.getPropertyBoolean("General.MPP", iMPP);
051    }
052    
053    @Override
054    public String getWeightName() {
055        return "Exams.PerturbationWeight";
056    }
057    
058    @Override
059    public String getXmlWeightName() {
060        return "perturbationWeight";
061    }
062    
063    @Override
064    public double getWeightDefault(DataProperties config) {
065        return 0.01;
066    }
067    
068    public boolean isMPP() {
069        return iMPP;
070    }
071    
072    @Override
073    public void getXmlParameters(Map<String, String> params) {
074        params.put(getXmlWeightName(), String.valueOf(getWeight()));
075        params.put("mpp", isMPP() ? "true" : "false");
076    }
077    
078    @Override
079    public void setXmlParameters(Map<String, String> params) {
080        try {
081            setWeight(Double.valueOf(params.get(getXmlWeightName())));
082        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
083        try {
084            iMPP = "true".equals(params.get("mpp"));
085        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
086    }
087
088    @Override
089    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
090        if (!isMPP()) return 0;
091        Exam exam = value.variable();
092        ExamPlacement initial = exam.getInitialAssignment();
093        if (initial == null) return 0;
094        return Math.abs(initial.getPeriod().getIndex() - value.getPeriod().getIndex()) * (1 + exam.getSize());
095    }
096
097    @Override
098    public String toString(Assignment<Exam, ExamPlacement> assignment) {
099        return (isMPP() ? "IP:" + sDoubleFormat.format(getValue(assignment)) : "");
100    }
101}