    001package net.sf.cpsolver.exam.criteria;
    002
    003import java.util.Map;
    004import java.util.Set;
    005
    006import net.sf.cpsolver.exam.model.Exam;
    007import net.sf.cpsolver.exam.model.ExamPlacement;
    008import net.sf.cpsolver.ifs.solver.Solver;
    009import net.sf.cpsolver.ifs.util.DataProperties;
    010
    011/**
    012 * Perturbation penalty. I.e., penalty for using a different examination period than
    013 * initial. Only applicable when {@link PerturbationPenalty#isMPP()} is true (minimal
    014 * perturbation problem).
    015 * <br><br>
    016 * A weight of perturbations (i.e., a penalty for an
    017 * assignment of an exam to a place different from the initial one) can be
    018 * set by problem property Exams.PerturbationWeight, or in the input xml
    019 * file, property perturbationWeight).
    020 *
    021 * <br>
    022 *
    023 * @version ExamTT 1.2 (Examination Timetabling)<br>
    024 *          Copyright (C) 2008 - 2012 Tomáš Müller<br>
    025 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    026 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    027 * <br>
    028 *          This library is free software; you can redistribute it and/or modify
    029 *          it under the terms of the GNU Lesser General Public License as
    030 *          published by the Free Software Foundation; either version 3 of the
    031 *          License, or (at your option) any later version. <br>
    032 * <br>
    033 *          This library is distributed in the hope that it will be useful, but
    034 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    035 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    036 *          Lesser General Public License for more details. <br>
    037 * <br>
    038 *          You should have received a copy of the GNU Lesser General Public
    039 *          License along with this library; if not see
    040 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    041 */
    042public class PerturbationPenalty extends ExamCriterion {
    043    private boolean iMPP = false;
    044
    045    @Override
    046    public boolean init(Solver<Exam, ExamPlacement> solver) {
    047        boolean ret = super.init(solver);
    048        iMPP = solver.getProperties().getPropertyBoolean("General.MPP", iMPP);
    049        return ret;
    050    }
    051
    052    @Override
    053    public String getWeightName() {
    054        return "Exams.PerturbationWeight";
    055    }
    056
    057    @Override
    058    public String getXmlWeightName() {
    059        return "perturbationWeight";
    060    }
    061
    062    @Override
    063    public double getWeightDefault(DataProperties config) {
    064        return 0.01;
    065    }
    066
    067    public boolean isMPP() {
    068        return iMPP;
    069    }
    070
    071    @Override
    072    public void getXmlParameters(Map<String, String> params) {
    073        params.put(getXmlWeightName(), String.valueOf(getWeight()));
    074        params.put("mpp", isMPP() ? "true" : "false");
    075    }
    076
    077    @Override
    078    public void setXmlParameters(Map<String, String> params) {
    079        try {
    080            setWeight(Double.valueOf(params.get(getXmlWeightName())));
    081        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
    082        try {
    083            iMPP = "true".equals(params.get("mpp"));
    084        } catch (NumberFormatException e) {} catch (NullPointerException e) {}
    085    }
    086
    087    @Override
    088    public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
    089        if (!isMPP()) return 0;
    090        Exam exam = value.variable();
    091        ExamPlacement initial = exam.getInitialAssignment();
    092        if (initial == null) return 0;
    093        return Math.abs(initial.getPeriod().getIndex() - value.getPeriod().getIndex()) * (1 + exam.getSize());
    094    }
    095
    096    @Override
    097    public String toString() {
    098        return (isMPP() ? "IP:" + sDoubleFormat.format(getValue()) : "");
    099    }
    100}