001package net.sf.cpsolver.exam.neighbours;
002
003import java.text.DecimalFormat;
004
005import org.apache.log4j.Logger;
006
007import net.sf.cpsolver.exam.model.Exam;
008import net.sf.cpsolver.exam.model.ExamModel;
009import net.sf.cpsolver.exam.model.ExamPlacement;
010import net.sf.cpsolver.ifs.model.SimpleNeighbour;
011
012/**
013 * Extension of {@link SimpleNeighbour}. The only difference is that the value (
014 * {@link SimpleNeighbour#value()}) is decreased by 1000 if the selected
015 * variable has no current assignment. <br>
016 * <br>
017 * 
018 * @version ExamTT 1.2 (Examination Timetabling)<br>
019 *          Copyright (C) 2008 - 2010 Tomáš Müller<br>
020 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
021 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
022 * <br>
023 *          This library is free software; you can redistribute it and/or modify
024 *          it under the terms of the GNU Lesser General Public License as
025 *          published by the Free Software Foundation; either version 3 of the
026 *          License, or (at your option) any later version. <br>
027 * <br>
028 *          This library is distributed in the hope that it will be useful, but
029 *          WITHOUT ANY WARRANTY; without even the implied warranty of
030 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
031 *          Lesser General Public License for more details. <br>
032 * <br>
033 *          You should have received a copy of the GNU Lesser General Public
034 *          License along with this library; if not see
035 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
036 */
037public class ExamSimpleNeighbour extends SimpleNeighbour<Exam, ExamPlacement> {
038    private static Logger sLog = Logger.getLogger(ExamSimpleNeighbour.class);
039    private static boolean sCheck = false;
040    private double iValue = 0;
041    private double iDx;
042
043    public ExamSimpleNeighbour(ExamPlacement placement) {
044        super(placement.variable(), placement);
045        iValue = placement.toDouble();
046        if (placement.variable().getAssignment() != null)
047            iValue -= placement.variable().getAssignment().toDouble();
048        else
049            iValue -= 1000;
050        if (sCheck) {
051            iDx = placement.toDouble();
052            if (placement.variable().getAssignment() != null)
053                iDx -= placement.variable().getAssignment().toDouble();
054        }
055    }
056
057    @Override
058    public void assign(long iteration) {
059        if (sCheck) {
060            double beforeVal = getVariable().getModel().getTotalValue();
061            double[] beforeValM = ((ExamModel) getVariable().getModel()).getTotalMultiValue();
062            String n = toString();
063            getVariable().assign(iteration, getValue());
064            double afterVal = getVariable().getModel().getTotalValue();
065            double[] afterValM = ((ExamModel) getVariable().getModel()).getTotalMultiValue();
066            /*
067             * int before = getVariable().getModel().nrUnassignedVariables();
068             * int after = getVariable().getModel().nrUnassignedVariables(); if
069             * (after>before) {
070             * sLog.error("-- assignment mischmatch (delta:"+(after
071             * -before)+")"); sLog.error("  -- neighbour: "+n); }
072             */
073            if (Math.abs(afterVal - beforeVal - iDx) >= 0.0000001) {
074                sLog.error("-- value mischmatch (delta:" + (afterVal - beforeVal) + ", value:" + iDx + ")");
075                sLog.error("  -- neighbour: " + n);
076                sLog.error("  -- solution:  " + toString(afterValM, beforeValM));
077            }
078        } else {
079            getVariable().assign(iteration, getValue());
080        }
081    }
082
083    protected static String toString(double[] x) {
084        DecimalFormat df = new DecimalFormat("0.00");
085        StringBuffer s = new StringBuffer();
086        for (int i = 0; i < x.length; i++) {
087            if (i > 0)
088                s.append(",");
089            s.append(df.format(x[i]));
090        }
091        return "[" + s.toString() + "]";
092    }
093
094    protected static String toString(double[] x, double[] y) {
095        DecimalFormat df = new DecimalFormat("0.00");
096        StringBuffer s = new StringBuffer();
097        for (int i = 0; i < x.length; i++) {
098            if (i > 0)
099                s.append(",");
100            s.append(df.format(x[i] - y[i]));
101        }
102        return "[" + s.toString() + "]";
103    }
104
105    @Override
106    public String toString() {
107        return getVariable().getAssignment() + " -> " + getValue().toString() + " / " + " (value:" + value() + ")";
108    }
109
110    @Override
111    public double value() {
112        return iValue;
113    }
114}