    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}