[12228] | 1 | #region License Information
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| 2 | /* HeuristicLab
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[16453] | 3 | * Copyright (C) 2002-2019 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
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[12228] | 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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[13412] | 23 | using System.Threading;
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[12228] | 24 | using HeuristicLab.Common;
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| 25 | using HeuristicLab.Core;
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| 26 | using HeuristicLab.Data;
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| 27 | using HeuristicLab.Encodings.PermutationEncoding;
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| 28 | using HeuristicLab.Operators;
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| 29 | using HeuristicLab.Optimization;
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| 30 | using HeuristicLab.Parameters;
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[16559] | 31 | using HEAL.Attic;
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[12228] | 32 |
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| 33 | namespace HeuristicLab.Problems.PTSP {
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| 34 | /// <summary>
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| 35 | /// An operator that improves probabilistic traveling salesman solutions.
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| 36 | /// </summary>
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| 37 | /// <remarks>
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| 38 | /// The operator tries to improve the probabilistic traveling salesman solution by swapping two randomly chosen edges for a certain number of times.
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| 39 | /// </remarks>
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[13470] | 40 | [Item("PTSP Estimated 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.")]
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[16462] | 41 | [StorableType("8B04265A-50AD-4FAD-99F8-2357D6F10CC3")]
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[13470] | 42 | public sealed class PTSPEstimatedTwoPointFiveLocalImprovement : SingleSuccessorOperator, IEstimatedPTSPOperator, ILocalImprovementOperator {
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[13412] | 43 |
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[12228] | 44 | public ILookupParameter<IntValue> LocalIterationsParameter {
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| 45 | get { return (ILookupParameter<IntValue>)Parameters["LocalIterations"]; }
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| 46 | }
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| 47 |
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| 48 | public IValueLookupParameter<IntValue> MaximumIterationsParameter {
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| 49 | get { return (IValueLookupParameter<IntValue>)Parameters["MaximumIterations"]; }
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| 50 | }
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| 51 |
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| 52 | public ILookupParameter<IntValue> EvaluatedSolutionsParameter {
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| 53 | get { return (ILookupParameter<IntValue>)Parameters["EvaluatedSolutions"]; }
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| 54 | }
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| 55 |
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| 56 | public ILookupParameter<ResultCollection> ResultsParameter {
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| 57 | get { return (ILookupParameter<ResultCollection>)Parameters["Results"]; }
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| 58 | }
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| 59 |
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| 60 | public ILookupParameter<Permutation> PermutationParameter {
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| 61 | get { return (ILookupParameter<Permutation>)Parameters["Permutation"]; }
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| 62 | }
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| 63 |
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| 64 | public ILookupParameter<DoubleValue> QualityParameter {
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| 65 | get { return (ILookupParameter<DoubleValue>)Parameters["Quality"]; }
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| 66 | }
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| 67 |
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| 68 | public ILookupParameter<BoolValue> MaximizationParameter {
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| 69 | get { return (ILookupParameter<BoolValue>)Parameters["Maximization"]; }
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| 70 | }
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| 71 |
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| 72 | public ILookupParameter<DistanceMatrix> DistanceMatrixParameter {
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| 73 | get { return (ILookupParameter<DistanceMatrix>)Parameters["DistanceMatrix"]; }
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| 74 | }
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| 75 |
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[13412] | 76 | public ILookupParameter<ItemList<BoolArray>> RealizationsParameter {
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| 77 | get { return (ILookupParameter<ItemList<BoolArray>>)Parameters["Realizations"]; }
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[12228] | 78 | }
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| 79 |
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| 80 | [StorableConstructor]
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[16462] | 81 | private PTSPEstimatedTwoPointFiveLocalImprovement(StorableConstructorFlag _) : base(_) { }
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[13470] | 82 | private PTSPEstimatedTwoPointFiveLocalImprovement(PTSPEstimatedTwoPointFiveLocalImprovement original, Cloner cloner) : base(original, cloner) { }
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| 83 | public PTSPEstimatedTwoPointFiveLocalImprovement()
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[12228] | 84 | : base() {
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| 85 | Parameters.Add(new LookupParameter<Permutation>("Permutation", "The solution as permutation."));
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| 86 | Parameters.Add(new LookupParameter<IntValue>("LocalIterations", "The number of iterations that have already been performed."));
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| 87 | 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)));
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| 88 | 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)."));
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| 89 | Parameters.Add(new LookupParameter<ResultCollection>("Results", "The collection where to store results."));
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| 90 | Parameters.Add(new LookupParameter<DoubleValue>("Quality", "The quality value of the assignment."));
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| 91 | Parameters.Add(new LookupParameter<BoolValue>("Maximization", "True if the problem should be maximized or minimized."));
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| 92 | Parameters.Add(new LookupParameter<DistanceMatrix>("DistanceMatrix", "The matrix which contains the distances between the cities."));
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[13412] | 93 | Parameters.Add(new LookupParameter<ItemList<BoolArray>>("Realizations", "The list of samples drawn from all possible stochastic instances."));
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[12228] | 94 | }
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| 95 |
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| 96 | public override IDeepCloneable Clone(Cloner cloner) {
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[13470] | 97 | return new PTSPEstimatedTwoPointFiveLocalImprovement(this, cloner);
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[12228] | 98 | }
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| 99 |
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[13470] | 100 | public static void Improve(Permutation assignment, DoubleMatrix distances, DoubleValue quality, IntValue localIterations, IntValue evaluatedSolutions, bool maximization, int maxIterations, ItemList<BoolArray> realizations, CancellationToken cancellation) {
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[13412] | 101 | var distanceM = (DistanceMatrix)distances;
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[13470] | 102 | Func<int, int, double> distance = (a, b) => distanceM[a, b];
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[13412] | 103 | for (var i = localIterations.Value; i < maxIterations; i++) {
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[13470] | 104 | TwoPointFiveMove bestMove = null;
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| 105 | var bestQuality = 0.0; // we have to make an improvement, so 0 is the baseline
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| 106 | var evaluations = 0.0;
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| 107 | foreach (var move in ExhaustiveTwoPointFiveMoveGenerator.Generate(assignment)) {
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| 108 | var moveQuality = PTSPEstimatedTwoPointFiveMoveEvaluator.EvaluateMove(assignment, move, distance, realizations);
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| 109 | if (move.IsInvert) evaluations += realizations.Count * 4.0 / (assignment.Length * assignment.Length);
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| 110 | else evaluations += realizations.Count * 6.0 / (assignment.Length * assignment.Length);
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[12228] | 111 | if (maximization && moveQuality > bestQuality
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| 112 | || !maximization && moveQuality < bestQuality) {
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| 113 | bestQuality = moveQuality;
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| 114 | bestMove = move;
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| 115 | }
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| 116 | }
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| 117 | evaluatedSolutions.Value += (int)Math.Ceiling(evaluations);
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| 118 | if (bestMove == null) break;
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[13470] | 119 | TwoPointFiveMoveMaker.Apply(assignment, bestMove);
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[12228] | 120 | quality.Value += bestQuality;
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| 121 | localIterations.Value++;
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| 122 | cancellation.ThrowIfCancellationRequested();
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| 123 | }
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| 124 | }
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| 125 |
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| 126 | public override IOperation Apply() {
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| 127 | var maxIterations = MaximumIterationsParameter.ActualValue.Value;
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| 128 | var assignment = PermutationParameter.ActualValue;
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| 129 | var maximization = MaximizationParameter.ActualValue.Value;
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| 130 | var distances = DistanceMatrixParameter.ActualValue;
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| 131 | var quality = QualityParameter.ActualValue;
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| 132 | var localIterations = LocalIterationsParameter.ActualValue;
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| 133 | var evaluations = EvaluatedSolutionsParameter.ActualValue;
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[13412] | 134 | var realizations = RealizationsParameter.ActualValue;
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[12228] | 135 | if (localIterations == null) {
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| 136 | localIterations = new IntValue(0);
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| 137 | LocalIterationsParameter.ActualValue = localIterations;
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| 138 | }
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| 139 |
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[13470] | 140 | Improve(assignment, distances, quality, localIterations, evaluations, maximization, maxIterations, realizations, CancellationToken);
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[12228] | 141 |
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| 142 | localIterations.Value = 0;
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| 143 | return base.Apply();
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| 144 | }
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| 145 | }
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| 146 | }
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