001 package net.sf.cpsolver.ifs.criteria;
002
003 import java.util.Collection;
004 import java.util.Set;
005
006 import net.sf.cpsolver.ifs.model.InfoProvider;
007 import net.sf.cpsolver.ifs.model.ModelListener;
008 import net.sf.cpsolver.ifs.model.Value;
009 import net.sf.cpsolver.ifs.model.Variable;
010
011 /**
012 * Criterion. <br>
013 * <br>
014 * An optimization objective can be split into several (optimization) criteria
015 * and modeled as a weighted sum of these. This makes the implementation of a particular problem
016 * more versatile as it allows for an easier modification of the optimization objective.
017 *
018 * @version IFS 1.2 (Iterative Forward Search)<br>
019 * Copyright (C) 2006 - 2011 Tomas Muller<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 */
037 public interface Criterion<V extends Variable<V, T>, T extends Value<V, T>> extends ModelListener<V, T>, InfoProvider<V> {
038
039 /** Current value of the criterion (optimization objective) */
040 public double getValue();
041
042 /** Weighted value of the objectives */
043 public double getWeightedValue();
044
045 /** Bounds (minimum and maximum) estimate for the value */
046 public double[] getBounds();
047
048 /** Weighted best value of the objective (value in the best solution). */
049 public double getWeightedBest();
050
051 /** Best value (value of the criterion in the best solution) */
052 public double getBest();
053
054 /** Weight of the criterion */
055 public double getWeight();
056
057 /** Weighted value of a proposed assignment (including hard conflicts) */
058 public double getWeightedValue(T value, Set<T> conflicts);
059
060 /** Value of a proposed assignment (including hard conflicts) */
061 public double getValue(T value, Set<T> conflicts);
062
063 /** Weighted value of a part of the problem (given by the collection of variables) */
064 public double getWeightedValue(Collection<V> variables);
065
066 /** Value of a part of the problem (given by the collection of variables) */
067 public double getValue(Collection<V> variables);
068
069 /** Value bounds (minimum and maximum) of the criterion on a part of the problem */
070 public double[] getBounds(Collection<V> variables);
071
072 /** Criterion name */
073 public String getName();
074
075 /** Outside update of the criterion (usefull when the criterion is driven by a set of constraints). */
076 public void inc(double value);
077
078 /** Notification that the current solution has been saved to the best. */
079 public void bestSaved();
080
081 /** Notification that the current solution has been restored from the best. */
082 public void bestRestored();
083 }