source: trunk/sources/HeuristicLab.Problems.QuadraticAssignment/3.3/LocalImprovement/QAPExhaustiveInversionLocalImprovement.cs @ 12811

Last change on this file since 12811 was 12811, checked in by abeham, 4 years ago

#2445: fixed behavior of counting evaluated solutions

File size: 6.8 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2015 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using System;
23using System.Threading;
24using HeuristicLab.Common;
25using HeuristicLab.Core;
26using HeuristicLab.Data;
27using HeuristicLab.Encodings.PermutationEncoding;
28using HeuristicLab.Operators;
29using HeuristicLab.Optimization;
30using HeuristicLab.Parameters;
31using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
32
33namespace HeuristicLab.Problems.QuadraticAssignment {
34  [Item("QAPExhaustiveInversionLocalImprovement", "Takes a solution and finds the local optimum with respect to the inversion neighborhood by decending along the steepest gradient.")]
35  [StorableClass]
36  public class QAPExhaustiveInversionLocalImprovement : SingleSuccessorOperator, ILocalImprovementOperator, ISingleObjectiveOperator {
37
38    public ILookupParameter<IntValue> LocalIterationsParameter {
39      get { return (ILookupParameter<IntValue>)Parameters["LocalIterations"]; }
40    }
41
42    public IValueLookupParameter<IntValue> MaximumIterationsParameter {
43      get { return (IValueLookupParameter<IntValue>)Parameters["MaximumIterations"]; }
44    }
45
46    public ILookupParameter<IntValue> EvaluatedSolutionsParameter {
47      get { return (ILookupParameter<IntValue>)Parameters["EvaluatedSolutions"]; }
48    }
49
50    public ILookupParameter<ResultCollection> ResultsParameter {
51      get { return (ILookupParameter<ResultCollection>)Parameters["Results"]; }
52    }
53
54    public ILookupParameter<Permutation> AssignmentParameter {
55      get { return (ILookupParameter<Permutation>)Parameters["Assignment"]; }
56    }
57
58    public ILookupParameter<DoubleValue> QualityParameter {
59      get { return (ILookupParameter<DoubleValue>)Parameters["Quality"]; }
60    }
61
62    public ILookupParameter<BoolValue> MaximizationParameter {
63      get { return (ILookupParameter<BoolValue>)Parameters["Maximization"]; }
64    }
65
66    public ILookupParameter<DoubleMatrix> WeightsParameter {
67      get { return (ILookupParameter<DoubleMatrix>)Parameters["Weights"]; }
68    }
69
70    public ILookupParameter<DoubleMatrix> DistancesParameter {
71      get { return (ILookupParameter<DoubleMatrix>)Parameters["Distances"]; }
72    }
73
74    [StorableConstructor]
75    protected QAPExhaustiveInversionLocalImprovement(bool deserializing) : base(deserializing) { }
76    protected QAPExhaustiveInversionLocalImprovement(QAPExhaustiveInversionLocalImprovement original, Cloner cloner)
77      : base(original, cloner) {
78    }
79    public QAPExhaustiveInversionLocalImprovement()
80      : base() {
81      Parameters.Add(new LookupParameter<IntValue>("LocalIterations", "The number of iterations that have already been performed."));
82      Parameters.Add(new ValueLookupParameter<IntValue>("MaximumIterations", "The maximum amount of iterations that should be performed (note that this operator will abort earlier when a local optimum is reached).", new IntValue(10000)));
83      Parameters.Add(new LookupParameter<IntValue>("EvaluatedSolutions", "The amount of evaluated solutions (here a move is counted only as 4/n evaluated solutions with n being the length of the permutation)."));
84      Parameters.Add(new LookupParameter<ResultCollection>("Results", "The collection where to store results."));
85      Parameters.Add(new LookupParameter<Permutation>("Assignment", "The permutation that is to be locally optimized."));
86      Parameters.Add(new LookupParameter<DoubleValue>("Quality", "The quality value of the assignment."));
87      Parameters.Add(new LookupParameter<BoolValue>("Maximization", "True if the problem should be maximized or minimized."));
88      Parameters.Add(new LookupParameter<DoubleMatrix>("Weights", "The weights matrix."));
89      Parameters.Add(new LookupParameter<DoubleMatrix>("Distances", "The distances matrix."));
90    }
91
92    public override IDeepCloneable Clone(Cloner cloner) {
93      return new QAPExhaustiveInversionLocalImprovement(this, cloner);
94    }
95
96    public static void Improve(Permutation assignment, DoubleMatrix weights, DoubleMatrix distances, DoubleValue quality, IntValue localIterations, IntValue evaluatedSolutions, bool maximization, int maxIterations, CancellationToken cancellation) {
97      for (int i = localIterations.Value; i < maxIterations; i++) {
98        InversionMove bestMove = null;
99        double bestQuality = 0; // we have to make an improvement, so 0 is the baseline
100        double evaluations = 0.0;
101        foreach (var move in ExhaustiveInversionMoveGenerator.Generate(assignment)) {
102          double moveQuality = QAPInversionMoveEvaluator.Apply(assignment, move, weights, distances);
103          evaluations += 2 * (move.Index2 - move.Index1 + 1) / (double)assignment.Length;
104          if (maximization && moveQuality > bestQuality
105            || !maximization && moveQuality < bestQuality) {
106            bestQuality = moveQuality;
107            bestMove = move;
108          }
109        }
110        evaluatedSolutions.Value += (int)Math.Ceiling(evaluations);
111        if (bestMove == null) break;
112        InversionManipulator.Apply(assignment, bestMove.Index1, bestMove.Index2);
113        quality.Value += bestQuality;
114        localIterations.Value++;
115        cancellation.ThrowIfCancellationRequested();
116      }
117    }
118
119    public override IOperation Apply() {
120      var maxIterations = MaximumIterationsParameter.ActualValue.Value;
121      var assignment = AssignmentParameter.ActualValue;
122      var maximization = MaximizationParameter.ActualValue.Value;
123      var weights = WeightsParameter.ActualValue;
124      var distances = DistancesParameter.ActualValue;
125      var quality = QualityParameter.ActualValue;
126      var localIterations = LocalIterationsParameter.ActualValue;
127      var evaluations = EvaluatedSolutionsParameter.ActualValue;
128      if (localIterations == null) {
129        localIterations = new IntValue(0);
130        LocalIterationsParameter.ActualValue = localIterations;
131      }
132
133      Improve(assignment, weights, distances, quality, localIterations, evaluations, maximization, maxIterations, CancellationToken);
134
135      localIterations.Value = 0;
136      return base.Apply();
137    }
138  }
139}
Note: See TracBrowser for help on using the repository browser.