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source: branches/2521_ProblemRefactoring/HeuristicLab.Problems.PTSP/3.3/Improvers/PTSPAnalyticalTwoPointFiveLocalImprovement.cs @ 17260

Last change on this file since 17260 was 17260, checked in by abeham, 4 years ago

#2521: Worked on PTSP refactoring

File size: 6.8 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 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 HEAL.Attic;
25using HeuristicLab.Common;
26using HeuristicLab.Core;
27using HeuristicLab.Data;
28using HeuristicLab.Encodings.PermutationEncoding;
29using HeuristicLab.Operators;
30using HeuristicLab.Optimization;
31using HeuristicLab.Parameters;
32
33namespace HeuristicLab.Problems.PTSP {
34  /// <summary>
35  /// An operator that improves probabilistic traveling salesman solutions.
36  /// </summary>
37  /// <remarks>
38  /// The operator tries to improve the probabilistic traveling salesman solution by swapping two randomly chosen edges for a certain number of times.
39  /// </remarks>
40  [Item("pTSP Analytical 2.5 Local Improvement", "An operator that improves probabilistic traveling salesman solutions. The operator tries to improve the probabilistic traveling salesman solution by swapping two randomly chosen edges for a certain number of times.")]
41  [StorableType("6e07195e-0da7-45ea-9385-0c66594127db")]
42  public sealed class PTSPAnalyticalTwoPointFiveLocalImprovement : SingleSuccessorOperator, IAnalyticalPTSPOperator, ILocalImprovementOperator {
43
44    public ILookupParameter<IntValue> LocalIterationsParameter {
45      get { return (ILookupParameter<IntValue>)Parameters["LocalIterations"]; }
46    }
47
48    public IValueLookupParameter<IntValue> MaximumIterationsParameter {
49      get { return (IValueLookupParameter<IntValue>)Parameters["MaximumIterations"]; }
50    }
51
52    public ILookupParameter<IntValue> EvaluatedSolutionsParameter {
53      get { return (ILookupParameter<IntValue>)Parameters["EvaluatedSolutions"]; }
54    }
55
56    public ILookupParameter<ResultCollection> ResultsParameter {
57      get { return (ILookupParameter<ResultCollection>)Parameters["Results"]; }
58    }
59
60    public ILookupParameter<Permutation> PermutationParameter {
61      get { return (ILookupParameter<Permutation>)Parameters["Permutation"]; }
62    }
63
64    public ILookupParameter<DoubleValue> QualityParameter {
65      get { return (ILookupParameter<DoubleValue>)Parameters["Quality"]; }
66    }
67
68    public ILookupParameter<BoolValue> MaximizationParameter {
69      get { return (ILookupParameter<BoolValue>)Parameters["Maximization"]; }
70    }
71
72    public ILookupParameter<IProbabilisticTSPData> ProbabilisticTSPDataParameter {
73      get { return (ILookupParameter<IProbabilisticTSPData>)Parameters["PTSP Data"]; }
74    }
75
76    [StorableConstructor]
77    private PTSPAnalyticalTwoPointFiveLocalImprovement(StorableConstructorFlag _) : base(_) { }
78    private PTSPAnalyticalTwoPointFiveLocalImprovement(PTSPAnalyticalTwoPointFiveLocalImprovement original, Cloner cloner) : base(original, cloner) { }
79    public PTSPAnalyticalTwoPointFiveLocalImprovement()
80      : base() {
81      Parameters.Add(new LookupParameter<Permutation>("Permutation", "The solution as permutation."));
82      Parameters.Add(new LookupParameter<IntValue>("LocalIterations", "The number of iterations that have already been performed."));
83      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)));
84      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)."));
85      Parameters.Add(new LookupParameter<ResultCollection>("Results", "The collection where to store results."));
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<IProbabilisticTSPData>("PTSP Data", "The main parameters of the pTSP."));
89    }
90
91    public override IDeepCloneable Clone(Cloner cloner) {
92      return new PTSPAnalyticalTwoPointFiveLocalImprovement(this, cloner);
93    }
94
95    public static void Improve(Permutation assignment, IProbabilisticTSPData data, DoubleValue quality, IntValue localIterations, IntValue evaluatedSolutions, bool maximization, int maxIterations, CancellationToken cancellation) {
96      for (var i = localIterations.Value; i < maxIterations; i++) {
97        TwoPointFiveMove bestMove = null;
98        var bestQuality = quality.Value; // we have to make an improvement, so current quality is the baseline
99        var evaluations = 0.0;
100        foreach (var move in ExhaustiveTwoPointFiveMoveGenerator.Generate(assignment)) {
101          var moveQuality = PTSPAnalyticalTwoPointFiveMoveEvaluator.EvaluateMove(assignment, move, data);
102          evaluations++;
103          if (maximization && moveQuality > bestQuality
104            || !maximization && moveQuality < bestQuality) {
105            bestQuality = moveQuality;
106            bestMove = move;
107          }
108        }
109        evaluatedSolutions.Value += (int)Math.Ceiling(evaluations);
110        if (bestMove == null) break;
111        TwoPointFiveMoveMaker.Apply(assignment, bestMove);
112        quality.Value = bestQuality;
113        localIterations.Value++;
114        cancellation.ThrowIfCancellationRequested();
115      }
116    }
117
118    public override IOperation Apply() {
119      var maxIterations = MaximumIterationsParameter.ActualValue.Value;
120      var assignment = PermutationParameter.ActualValue;
121      var maximization = MaximizationParameter.ActualValue.Value;
122      var quality = QualityParameter.ActualValue;
123      var localIterations = LocalIterationsParameter.ActualValue;
124      var evaluations = EvaluatedSolutionsParameter.ActualValue;
125      var data = ProbabilisticTSPDataParameter.ActualValue;
126      if (localIterations == null) {
127        localIterations = new IntValue(0);
128        LocalIterationsParameter.ActualValue = localIterations;
129      }
130
131      Improve(assignment, data, quality, localIterations, evaluations, maximization, maxIterations, CancellationToken);
132
133      localIterations.Value = 0;
134      return base.Apply();
135    }
136  }
137}
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