    001package org.cpsolver.exam.criteria;
    002
    003import java.util.Collection;
    004import java.util.Set;
    005
    006import org.cpsolver.exam.criteria.additional.PeriodViolation;
    007import org.cpsolver.exam.model.Exam;
    008import org.cpsolver.exam.model.ExamPeriodPlacement;
    009import org.cpsolver.exam.model.ExamPlacement;
    010import org.cpsolver.ifs.assignment.Assignment;
    011import org.cpsolver.ifs.solver.Solver;
    012import org.cpsolver.ifs.util.DataProperties;
    013
    014
    015/**
    016 * Cost for using a period. See {@link ExamPeriodPlacement#getPenalty()} for more details.
    017 * <br><br>
    018 * A weight for period penalty can be set by problem property
    019 * Exams.PeriodWeight, or in the input xml file, property periodWeight.
    020 *
    021 * <br>
    022 *
    023 * @author  Tomáš Müller
    024 * @version ExamTT 1.3 (Examination Timetabling)<br>
    025 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
    026 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    027 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    028 * <br>
    029 *          This library is free software; you can redistribute it and/or modify
    030 *          it under the terms of the GNU Lesser General Public License as
    031 *          published by the Free Software Foundation; either version 3 of the
    032 *          License, or (at your option) any later version. <br>
    033 * <br>
    034 *          This library is distributed in the hope that it will be useful, but
    035 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    036 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    037 *          Lesser General Public License for more details. <br>
    038 * <br>
    039 *          You should have received a copy of the GNU Lesser General Public
    040 *          License along with this library; if not see
    041 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    042 */
    043public class PeriodPenalty extends ExamCriterion {
    044    protected Integer iSoftPeriods = null;
    045
    046    @Override
    047    public boolean init(Solver<Exam, ExamPlacement> solver) {
    048        if (super.init(solver)) {
    049            iSoftPeriods = solver.getProperties().getPropertyInteger("Exam.SoftPeriods", null);
    050            if (iSoftPeriods != null) {
    051                PeriodViolation pv = new PeriodViolation();
    052                getModel().addCriterion(pv);
    053                return pv.init(solver);
    054            }
    055        }
    056        return true;
    057    }
    058
    059    @Override
    060    public String getWeightName() {
    061        return "Exams.PeriodWeight";
    062    }
    063
    064    @Override
    065    public String getXmlWeightName() {
    066        return "periodWeight";
    067    }
    068
    069    @Override
    070    public double getWeightDefault(DataProperties config) {
    071        return 1.0;
    072    }
    073
    074    @Override
    075    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
    076        return (iSoftPeriods == null || (value.getPeriodPlacement().getExamPenalty() != iSoftPeriods &&  value.getPeriodPlacement().getPeriod().getPenalty() != iSoftPeriods) ? value.getPeriodPlacement().getPenalty() : 0.0);
    077    }
    078
    079    @Override
    080    public double[] getBounds(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) {
    081        double[] bounds = new double[] { 0.0, 0.0 };
    082        for (Exam exam : variables) {
    083            if (!exam.getPeriodPlacements().isEmpty()) {
    084                int minPenalty = Integer.MAX_VALUE, maxPenalty = Integer.MIN_VALUE;
    085                for (ExamPeriodPlacement periodPlacement : exam.getPeriodPlacements()) {
    086                    if (iSoftPeriods != null && (periodPlacement.getExamPenalty() == iSoftPeriods || periodPlacement.getPeriod().getPenalty() == iSoftPeriods)) continue;
    087                    minPenalty = Math.min(minPenalty, periodPlacement.getPenalty());
    088                    maxPenalty = Math.max(maxPenalty, periodPlacement.getPenalty());
    089                }
    090                bounds[0] += minPenalty;
    091                bounds[1] += maxPenalty;
    092            }
    093        }
    094        return bounds;
    095    }
    096
    097    @Override
    098    public String toString(Assignment<Exam, ExamPlacement> assignment) {
    099        return "PP:" + sDoubleFormat.format(getValue(assignment));
    100    }
    101}