    001package org.cpsolver.exam.neighbours;
    002
    003import java.text.DecimalFormat;
    004
    005import org.apache.logging.log4j.Logger;
    006import org.cpsolver.exam.model.Exam;
    007import org.cpsolver.exam.model.ExamModel;
    008import org.cpsolver.exam.model.ExamPlacement;
    009import org.cpsolver.ifs.assignment.Assignment;
    010import org.cpsolver.ifs.model.SimpleNeighbour;
    011
    012
    013/**
    014 * Extension of {@link SimpleNeighbour}. The only difference is that the value (
    015 * {@link SimpleNeighbour#value(Assignment)}) is decreased by 1000 if the selected
    016 * variable has no current assignment. <br>
    017 * <br>
    018 *
    019 * @author  Tomáš Müller
    020 * @version ExamTT 1.3 (Examination Timetabling)<br>
    021 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
    022 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    023 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    024 * <br>
    025 *          This library is free software; you can redistribute it and/or modify
    026 *          it under the terms of the GNU Lesser General Public License as
    027 *          published by the Free Software Foundation; either version 3 of the
    028 *          License, or (at your option) any later version. <br>
    029 * <br>
    030 *          This library is distributed in the hope that it will be useful, but
    031 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    032 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    033 *          Lesser General Public License for more details. <br>
    034 * <br>
    035 *          You should have received a copy of the GNU Lesser General Public
    036 *          License along with this library; if not see
    037 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    038 */
    039public class ExamSimpleNeighbour extends SimpleNeighbour<Exam, ExamPlacement> {
    040    private static Logger sLog = org.apache.logging.log4j.LogManager.getLogger(ExamSimpleNeighbour.class);
    041    private static boolean sCheck = false;
    042    private double iValue = 0;
    043    private double iDx;
    044
    045    public ExamSimpleNeighbour(Assignment<Exam, ExamPlacement> assignment, ExamPlacement placement) {
    046        super(placement.variable(), placement);
    047        iValue = placement.toDouble(assignment);
    048        ExamPlacement current = assignment.getValue(placement.variable());
    049        if (current != null)
    050            iValue -= current.toDouble(assignment);
    051        else
    052            iValue -= 1000;
    053        if (sCheck) {
    054            iDx = placement.toDouble(assignment);
    055            if (current != null)
    056                iDx -= current.toDouble(assignment);
    057        }
    058    }
    059
    060    @Override
    061    public void assign(Assignment<Exam, ExamPlacement> assignment, long iteration) {
    062        if (sCheck) {
    063            double beforeVal = getVariable().getModel().getTotalValue(assignment);
    064            double[] beforeValM = ((ExamModel) getVariable().getModel()).getTotalMultiValue(assignment);
    065            String n = toString();
    066            assignment.assign(iteration, getValue());
    067            double afterVal = getVariable().getModel().getTotalValue(assignment);
    068            double[] afterValM = ((ExamModel) getVariable().getModel()).getTotalMultiValue(assignment);
    069            /*
    070             * int before = getVariable().getModel().nrUnassignedVariables();
    071             * int after = getVariable().getModel().nrUnassignedVariables(); if
    072             * (after>before) {
    073             * sLog.error("-- assignment mischmatch (delta:"+(after
    074             * -before)+")"); sLog.error("  -- neighbour: "+n); }
    075             */
    076            if (Math.abs(afterVal - beforeVal - iDx) >= 0.0000001) {
    077                sLog.error("-- value mischmatch (delta:" + (afterVal - beforeVal) + ", value:" + iDx + ")");
    078                sLog.error("  -- neighbour: " + n);
    079                sLog.error("  -- solution:  " + toString(afterValM, beforeValM));
    080            }
    081        } else {
    082            assignment.assign(iteration, getValue());
    083        }
    084    }
    085
    086    protected static String toString(double[] x) {
    087        DecimalFormat df = new DecimalFormat("0.00");
    088        StringBuffer s = new StringBuffer();
    089        for (int i = 0; i < x.length; i++) {
    090            if (i > 0)
    091                s.append(",");
    092            s.append(df.format(x[i]));
    093        }
    094        return "[" + s.toString() + "]";
    095    }
    096
    097    protected static String toString(double[] x, double[] y) {
    098        DecimalFormat df = new DecimalFormat("0.00");
    099        StringBuffer s = new StringBuffer();
    100        for (int i = 0; i < x.length; i++) {
    101            if (i > 0)
    102                s.append(",");
    103            s.append(df.format(x[i] - y[i]));
    104        }
    105        return "[" + s.toString() + "]";
    106    }
    107
    108    @Override
    109    public String toString() {
    110        return getVariable() + " := " + getValue().toString() + " / " + " (value:" + value(null) + ")";
    111    }
    112
    113    @Override
    114    public double value(Assignment<Exam, ExamPlacement> assignment) {
    115        return iValue;
    116    }
    117}