1 | #region License Information
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2 | /* HeuristicLab
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3 | * Copyright (C) 2002-2016 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
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4 | *
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5 | * This file is part of HeuristicLab.
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6 | *
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7 | * HeuristicLab is free software: you can redistribute it and/or modify
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8 | * it under the terms of the GNU General Public License as published by
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9 | * the Free Software Foundation, either version 3 of the License, or
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10 | * (at your option) any later version.
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11 | *
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12 | * HeuristicLab is distributed in the hope that it will be useful,
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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15 | * GNU General Public License for more details.
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16 | *
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17 | * You should have received a copy of the GNU General Public License
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18 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
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19 | */
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20 | #endregion
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21 |
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22 | using System;
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23 | using HeuristicLab.Common;
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24 | using HeuristicLab.Core;
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25 | using HeuristicLab.Data;
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26 | using HeuristicLab.Encodings.PermutationEncoding;
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27 | using HeuristicLab.Operators;
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28 | using HeuristicLab.Optimization;
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29 | using HeuristicLab.Parameters;
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30 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
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31 |
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32 | namespace HeuristicLab.Problems.TravelingSalesman {
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33 | /// <summary>
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34 | /// An operator that improves traveling salesman solutions.
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35 | /// </summary>
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36 | /// <remarks>
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37 | /// The operator tries to improve the traveling salesman solution by swapping two randomly chosen edges for a certain number of times.
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38 | /// </remarks>
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39 | [Item("TSPImprovementOperator", "An operator that improves traveling salesman solutions. The operator tries to improve the traveling salesman solution by swapping two randomly chosen edges for a certain number of times.")]
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40 | [StorableClass]
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41 | public sealed class TSPImprovementOperator : SingleSuccessorOperator, ISingleObjectiveImprovementOperator {
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42 | #region Parameter properties
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43 | public ScopeParameter CurrentScopeParameter {
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44 | get { return (ScopeParameter)Parameters["CurrentScope"]; }
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45 | }
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46 | public ILookupParameter<DistanceMatrix> DistanceMatrixParameter {
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47 | get { return (ILookupParameter<DistanceMatrix>)Parameters["DistanceMatrix"]; }
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48 | }
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49 | public IValueParameter<IntValue> ImprovementAttemptsParameter {
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50 | get { return (IValueParameter<IntValue>)Parameters["ImprovementAttempts"]; }
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51 | }
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52 | public ILookupParameter<IRandom> RandomParameter {
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53 | get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
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54 | }
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55 | public IValueLookupParameter<IItem> SolutionParameter {
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56 | get { return (IValueLookupParameter<IItem>)Parameters["Solution"]; }
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57 | }
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58 | #endregion
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59 |
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60 | #region Properties
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61 | public IScope CurrentScope {
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62 | get { return CurrentScopeParameter.ActualValue; }
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63 | }
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64 | public DistanceMatrix DistanceMatrix {
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65 | get { return DistanceMatrixParameter.ActualValue; }
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66 | set { DistanceMatrixParameter.ActualValue = value; }
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67 | }
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68 | public IntValue ImprovementAttempts {
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69 | get { return ImprovementAttemptsParameter.Value; }
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70 | set { ImprovementAttemptsParameter.Value = value; }
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71 | }
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72 | public IRandom Random {
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73 | get { return RandomParameter.ActualValue; }
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74 | set { RandomParameter.ActualValue = value; }
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75 | }
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76 | #endregion
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77 |
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78 | [StorableConstructor]
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79 | private TSPImprovementOperator(bool deserializing) : base(deserializing) { }
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80 | private TSPImprovementOperator(TSPImprovementOperator original, Cloner cloner) : base(original, cloner) { }
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81 | public TSPImprovementOperator()
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82 | : base() {
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83 | #region Create parameters
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84 | Parameters.Add(new ScopeParameter("CurrentScope", "The current scope that contains the solution to be improved."));
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85 | Parameters.Add(new LookupParameter<DistanceMatrix>("DistanceMatrix", "The matrix which contains the distances between the cities."));
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86 | Parameters.Add(new ValueParameter<IntValue>("ImprovementAttempts", "The number of improvement attempts the operator should perform.", new IntValue(100)));
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87 | Parameters.Add(new LookupParameter<IRandom>("Random", "A pseudo random number generator."));
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88 | Parameters.Add(new ValueLookupParameter<IItem>("Solution", "The solution to be improved. This parameter is used for name translation only."));
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89 | #endregion
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90 | }
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91 |
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92 | public override IDeepCloneable Clone(Cloner cloner) {
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93 | return new TSPImprovementOperator(this, cloner);
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94 | }
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95 |
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96 | public override IOperation Apply() {
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97 | var solution = CurrentScope.Variables[SolutionParameter.ActualName].Value as Permutation;
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98 | if (solution == null)
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99 | throw new ArgumentException("Cannot improve solution because it has the wrong type.");
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100 | if (solution.PermutationType != PermutationTypes.RelativeUndirected)
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101 | throw new ArgumentException("Cannot improve solution because the permutation type is not supported.");
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102 |
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103 | for (int i = 0; i < ImprovementAttempts.Value; i++) {
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104 | var move = StochasticInversionSingleMoveGenerator.Apply(solution, Random);
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105 | double moveQualtiy = TSPInversionMovePathEvaluator.EvaluateByDistanceMatrix(solution, move, DistanceMatrix);
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106 | if (moveQualtiy < 0)
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107 | InversionManipulator.Apply(solution, move.Index1, move.Index2);
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108 | }
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109 |
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110 | CurrentScope.Variables.Add(new Variable("LocalEvaluatedSolutions", ImprovementAttempts));
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111 |
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112 | return base.Apply();
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113 | }
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114 | }
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115 | }
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