    001package org.cpsolver.exam.criteria;
    002
    003import java.util.Collection;
    004import java.util.Map;
    005import java.util.Set;
    006
    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.util.DataProperties;
    012
    013
    014/**
    015 * A weight for period penalty (used in
    016 * {@link ExamPeriodPlacement#getPenalty()} multiplied by examination size
    017 * {@link Exam#getSize()}. Can be set by problem property
    018 * Exams.PeriodSizeWeight, or in the input xml file, property periodSizeWeight).
    019 *
    020 * <br>
    021 *
    022 * @author  Tomáš Müller
    023 * @version ExamTT 1.3 (Examination Timetabling)<br>
    024 *          Copyright (C) 2008 - 2014 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 PeriodSizePenalty extends ExamCriterion {
    043
    044    @Override
    045    public String getWeightName() {
    046        return "Exams.PeriodSizeWeight";
    047    }
    048
    049    @Override
    050    public String getXmlWeightName() {
    051        return "periodSizeWeight";
    052    }
    053
    054    @Override
    055    public double getWeightDefault(DataProperties config) {
    056        return 1.0;
    057    }
    058
    059    @Override
    060    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
    061        return value.getPeriodPlacement().getPenalty() * (value.variable().getSize() + 1);
    062    }
    063
    064    @Override
    065    public String getName() {
    066        return "Period&times;Size Penalty";
    067    }
    068
    069    @Override
    070    public double[] getBounds(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) {
    071        double[] bounds = new double[] { 0.0, 0.0 };
    072        for (Exam exam : variables) {
    073            if (!exam.getPeriodPlacements().isEmpty()) {
    074                int minSizePenalty = Integer.MAX_VALUE, maxSizePenalty = Integer.MIN_VALUE;
    075                for (ExamPeriodPlacement periodPlacement : exam.getPeriodPlacements()) {
    076                    minSizePenalty = Math.min(minSizePenalty, periodPlacement.getPenalty() * (exam.getSize() + 1));
    077                    maxSizePenalty = Math.max(maxSizePenalty, periodPlacement.getPenalty() * (exam.getSize() + 1));
    078                }
    079                bounds[0] += minSizePenalty;
    080                bounds[1] += maxSizePenalty;
    081            }
    082        }
    083        return bounds;
    084    }
    085
    086    @Override
    087    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
    088        if (getValue(assignment) != 0.0) {
    089            info.put(getName(), sDoubleFormat.format(getValue(assignment) / assignment.nrAssignedVariables()));
    090        }
    091    }
    092
    093    @Override
    094    public String toString(Assignment<Exam, ExamPlacement> assignment) {
    095        return "PS:" + sDoubleFormat.format(getValue(assignment) / assignment.nrAssignedVariables());
    096    }
    097}