[16560] | 1 | using HeuristicLab.Analysis;
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| 2 | using HeuristicLab.Common;
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| 3 | using HeuristicLab.Core;
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| 4 | using HeuristicLab.Data;
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[16583] | 5 | using HeuristicLab.ExpressionGenerator;
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[16560] | 6 | using HeuristicLab.Optimization;
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| 7 | using HeuristicLab.Parameters;
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| 8 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
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| 9 | using HeuristicLab.Random;
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| 10 | using System;
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| 11 | using System.Collections.Generic;
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| 12 | using System.Linq;
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| 13 |
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| 14 | using CancellationToken = System.Threading.CancellationToken;
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| 15 |
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| 16 | namespace HeuristicLab.Algorithms.MOEAD {
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| 17 | [Item("MOEADAlgorithmBase", "Base class for all MOEA/D algorithm variants.")]
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| 18 | [StorableClass]
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| 19 | public abstract class MOEADAlgorithmBase : BasicAlgorithm {
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| 20 | #region data members
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| 21 | protected enum NeighborType { NEIGHBOR, POPULATION }
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| 22 | // TCHE = Chebyshev (Tchebyshev)
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| 23 | // PBI = Penalty-based boundary intersection
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| 24 | // AGG = Weighted sum
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| 25 | public enum FunctionType { TCHE, PBI, AGG }
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| 26 |
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| 27 | [Storable]
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| 28 | protected double[] IdealPoint { get; set; }
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| 29 | [Storable]
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| 30 | protected double[] NadirPoint { get; set; } // potentially useful for objective normalization
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| 31 |
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| 32 | [Storable]
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| 33 | protected double[][] lambda;
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| 34 |
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| 35 | [Storable]
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| 36 | protected int[][] neighbourhood;
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| 37 |
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| 38 | [Storable]
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| 39 | protected IList<IMOEADSolution> solutions;
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| 40 |
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| 41 | [Storable]
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| 42 | protected FunctionType functionType;
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| 43 |
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| 44 | [Storable]
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[16561] | 45 | protected List<IMOEADSolution> population;
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[16560] | 46 |
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| 47 | [Storable]
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[16561] | 48 | protected List<IMOEADSolution> offspringPopulation;
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[16560] | 49 |
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| 50 | [Storable]
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[16561] | 51 | protected List<IMOEADSolution> jointPopulation;
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[16560] | 52 |
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| 53 | [Storable]
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| 54 | protected int evaluatedSolutions;
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| 55 |
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| 56 | [Storable]
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| 57 | protected ExecutionContext executionContext;
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| 58 |
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| 59 | [Storable]
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| 60 | protected IScope globalScope;
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[16583] | 61 |
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| 62 | [Storable]
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| 63 | protected ExecutionState previousExecutionState;
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[16560] | 64 | #endregion
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| 65 |
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| 66 | #region parameters
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| 67 | private const string SeedParameterName = "Seed";
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| 68 | private const string SetSeedRandomlyParameterName = "SetSeedRandomly";
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| 69 | private const string PopulationSizeParameterName = "PopulationSize";
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| 70 | private const string ResultPopulationSizeParameterName = "ResultPopulationSize";
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| 71 | private const string CrossoverProbabilityParameterName = "CrossoverProbability";
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| 72 | private const string CrossoverParameterName = "Crossover";
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| 73 | private const string MutationProbabilityParameterName = "MutationProbability";
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| 74 | private const string MutatorParameterName = "Mutator";
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| 75 | private const string MaximumEvaluatedSolutionsParameterName = "MaximumEvaluatedSolutions";
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| 76 | private const string RandomParameterName = "Random";
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| 77 | private const string AnalyzerParameterName = "Analyzer";
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| 78 | // MOEA-D parameters
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| 79 | private const string NeighbourSizeParameterName = "NeighbourSize";
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| 80 | private const string NeighbourhoodSelectionProbabilityParameterName = "NeighbourhoodSelectionProbability";
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| 81 | private const string MaximumNumberOfReplacedSolutionsParameterName = "MaximumNumberOfReplacedSolutions";
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| 82 | private const string FunctionTypeParameterName = "FunctionType";
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| 83 |
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| 84 | public IValueParameter<MultiAnalyzer> AnalyzerParameter {
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| 85 | get { return (ValueParameter<MultiAnalyzer>)Parameters[AnalyzerParameterName]; }
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| 86 | }
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| 87 |
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| 88 | public IConstrainedValueParameter<StringValue> FunctionTypeParameter {
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| 89 | get { return (IConstrainedValueParameter<StringValue>)Parameters[FunctionTypeParameterName]; }
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| 90 | }
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| 91 | public IFixedValueParameter<IntValue> NeighbourSizeParameter {
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| 92 | get { return (IFixedValueParameter<IntValue>)Parameters[NeighbourSizeParameterName]; }
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| 93 | }
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| 94 | public IFixedValueParameter<IntValue> MaximumNumberOfReplacedSolutionsParameter {
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| 95 | get { return (IFixedValueParameter<IntValue>)Parameters[MaximumNumberOfReplacedSolutionsParameterName]; }
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| 96 | }
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| 97 | public IFixedValueParameter<DoubleValue> NeighbourhoodSelectionProbabilityParameter {
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| 98 | get { return (IFixedValueParameter<DoubleValue>)Parameters[NeighbourhoodSelectionProbabilityParameterName]; }
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| 99 | }
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| 100 | public IFixedValueParameter<IntValue> SeedParameter {
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| 101 | get { return (IFixedValueParameter<IntValue>)Parameters[SeedParameterName]; }
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| 102 | }
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| 103 | public IFixedValueParameter<BoolValue> SetSeedRandomlyParameter {
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| 104 | get { return (IFixedValueParameter<BoolValue>)Parameters[SetSeedRandomlyParameterName]; }
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| 105 | }
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| 106 | private IValueParameter<IntValue> PopulationSizeParameter {
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| 107 | get { return (IValueParameter<IntValue>)Parameters[PopulationSizeParameterName]; }
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| 108 | }
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| 109 | private IValueParameter<IntValue> ResultPopulationSizeParameter {
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| 110 | get { return (IValueParameter<IntValue>)Parameters[ResultPopulationSizeParameterName]; }
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| 111 | }
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| 112 | public IValueParameter<PercentValue> CrossoverProbabilityParameter {
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| 113 | get { return (IValueParameter<PercentValue>)Parameters[CrossoverProbabilityParameterName]; }
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| 114 | }
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| 115 | public IConstrainedValueParameter<ICrossover> CrossoverParameter {
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| 116 | get { return (IConstrainedValueParameter<ICrossover>)Parameters[CrossoverParameterName]; }
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| 117 | }
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| 118 | public IValueParameter<PercentValue> MutationProbabilityParameter {
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| 119 | get { return (IValueParameter<PercentValue>)Parameters[MutationProbabilityParameterName]; }
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| 120 | }
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| 121 | public IConstrainedValueParameter<IManipulator> MutatorParameter {
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| 122 | get { return (IConstrainedValueParameter<IManipulator>)Parameters[MutatorParameterName]; }
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| 123 | }
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| 124 | public IValueParameter<IntValue> MaximumEvaluatedSolutionsParameter {
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| 125 | get { return (IValueParameter<IntValue>)Parameters[MaximumEvaluatedSolutionsParameterName]; }
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| 126 | }
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| 127 | public IValueParameter<IRandom> RandomParameter {
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| 128 | get { return (IValueParameter<IRandom>)Parameters[RandomParameterName]; }
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| 129 | }
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| 130 | #endregion
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| 131 |
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| 132 | #region parameter properties
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| 133 | public new IMultiObjectiveHeuristicOptimizationProblem Problem {
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| 134 | get { return (IMultiObjectiveHeuristicOptimizationProblem)base.Problem; }
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| 135 | }
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| 136 | public int Seed {
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| 137 | get { return SeedParameter.Value.Value; }
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| 138 | set { SeedParameter.Value.Value = value; }
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| 139 | }
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| 140 | public bool SetSeedRandomly {
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| 141 | get { return SetSeedRandomlyParameter.Value.Value; }
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| 142 | set { SetSeedRandomlyParameter.Value.Value = value; }
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| 143 | }
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| 144 | public IntValue PopulationSize {
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| 145 | get { return PopulationSizeParameter.Value; }
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| 146 | set { PopulationSizeParameter.Value = value; }
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| 147 | }
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| 148 | public IntValue ResultPopulationSize {
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| 149 | get { return ResultPopulationSizeParameter.Value; }
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| 150 | set { ResultPopulationSizeParameter.Value = value; }
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| 151 | }
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| 152 | public PercentValue CrossoverProbability {
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| 153 | get { return CrossoverProbabilityParameter.Value; }
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| 154 | set { CrossoverProbabilityParameter.Value = value; }
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| 155 | }
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| 156 | public ICrossover Crossover {
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| 157 | get { return CrossoverParameter.Value; }
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| 158 | set { CrossoverParameter.Value = value; }
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| 159 | }
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| 160 | public PercentValue MutationProbability {
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| 161 | get { return MutationProbabilityParameter.Value; }
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| 162 | set { MutationProbabilityParameter.Value = value; }
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| 163 | }
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| 164 | public IManipulator Mutator {
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| 165 | get { return MutatorParameter.Value; }
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| 166 | set { MutatorParameter.Value = value; }
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| 167 | }
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| 168 | public MultiAnalyzer Analyzer {
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| 169 | get { return AnalyzerParameter.Value; }
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| 170 | set { AnalyzerParameter.Value = value; }
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| 171 | }
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| 172 | public IntValue MaximumEvaluatedSolutions {
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| 173 | get { return MaximumEvaluatedSolutionsParameter.Value; }
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| 174 | set { MaximumEvaluatedSolutionsParameter.Value = value; }
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| 175 | }
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| 176 | public int NeighbourSize {
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| 177 | get { return NeighbourSizeParameter.Value.Value; }
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| 178 | set { NeighbourSizeParameter.Value.Value = value; }
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| 179 | }
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| 180 | public int MaximumNumberOfReplacedSolutions {
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| 181 | get { return MaximumNumberOfReplacedSolutionsParameter.Value.Value; }
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| 182 | set { MaximumNumberOfReplacedSolutionsParameter.Value.Value = value; }
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| 183 | }
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| 184 | public double NeighbourhoodSelectionProbability {
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| 185 | get { return NeighbourhoodSelectionProbabilityParameter.Value.Value; }
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| 186 | set { NeighbourhoodSelectionProbabilityParameter.Value.Value = value; }
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| 187 | }
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| 188 | #endregion
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| 189 |
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| 190 | #region constructors
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| 191 | public MOEADAlgorithmBase() {
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| 192 | Parameters.Add(new FixedValueParameter<IntValue>(SeedParameterName, "The random seed used to initialize the new pseudo random number generator.", new IntValue(0)));
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| 193 | Parameters.Add(new FixedValueParameter<BoolValue>(SetSeedRandomlyParameterName, "True if the random seed should be set to a random value, otherwise false.", new BoolValue(true)));
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| 194 | Parameters.Add(new ValueParameter<IntValue>(PopulationSizeParameterName, "The size of the population of solutions.", new IntValue(100)));
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| 195 | Parameters.Add(new ValueParameter<IntValue>(ResultPopulationSizeParameterName, "The size of the population of solutions.", new IntValue(100)));
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| 196 | Parameters.Add(new ValueParameter<PercentValue>(CrossoverProbabilityParameterName, "The probability that the crossover operator is applied.", new PercentValue(0.9)));
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| 197 | Parameters.Add(new ConstrainedValueParameter<ICrossover>(CrossoverParameterName, "The operator used to cross solutions."));
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| 198 | Parameters.Add(new ValueParameter<PercentValue>(MutationProbabilityParameterName, "The probability that the mutation operator is applied on a solution.", new PercentValue(0.25)));
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| 199 | Parameters.Add(new ConstrainedValueParameter<IManipulator>(MutatorParameterName, "The operator used to mutate solutions."));
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| 200 | Parameters.Add(new ValueParameter<MultiAnalyzer>("Analyzer", "The operator used to analyze each generation.", new MultiAnalyzer()));
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| 201 | Parameters.Add(new ValueParameter<IntValue>(MaximumEvaluatedSolutionsParameterName, "The maximum number of evaluated solutions (approximately).", new IntValue(100_000)));
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| 202 | Parameters.Add(new ValueParameter<IRandom>(RandomParameterName, new MersenneTwister()));
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| 203 | Parameters.Add(new FixedValueParameter<IntValue>(NeighbourSizeParameterName, new IntValue(20)));
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| 204 | Parameters.Add(new FixedValueParameter<IntValue>(MaximumNumberOfReplacedSolutionsParameterName, new IntValue(2)));
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| 205 | Parameters.Add(new FixedValueParameter<DoubleValue>(NeighbourhoodSelectionProbabilityParameterName, new DoubleValue(0.1)));
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| 206 |
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| 207 | var functionTypeParameter = new ConstrainedValueParameter<StringValue>(FunctionTypeParameterName);
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| 208 | foreach (var s in new[] { "Chebyshev", "PBI", "Weighted Sum" }) {
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| 209 | functionTypeParameter.ValidValues.Add(new StringValue(s));
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| 210 | }
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| 211 | Parameters.Add(functionTypeParameter);
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| 212 | }
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| 213 |
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| 214 | protected MOEADAlgorithmBase(MOEADAlgorithmBase original, Cloner cloner) : base(original, cloner) {
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| 215 | functionType = original.functionType;
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| 216 | evaluatedSolutions = original.evaluatedSolutions;
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[16583] | 217 | previousExecutionState = original.previousExecutionState;
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[16560] | 218 |
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| 219 | if (original.IdealPoint != null) {
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| 220 | IdealPoint = (double[])original.IdealPoint.Clone();
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| 221 | }
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| 222 |
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| 223 | if (original.NadirPoint != null) {
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| 224 | NadirPoint = (double[])original.NadirPoint.Clone();
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| 225 | }
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| 226 |
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| 227 | if (original.lambda != null) {
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| 228 | lambda = (double[][])original.lambda.Clone();
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| 229 | }
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| 230 |
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| 231 | if (original.neighbourhood != null) {
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| 232 | neighbourhood = (int[][])original.neighbourhood.Clone();
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| 233 | }
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| 234 |
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| 235 | if (original.solutions != null) {
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| 236 | solutions = original.solutions.Select(cloner.Clone).ToArray();
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| 237 | }
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| 238 |
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| 239 | if (original.population != null) {
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[16561] | 240 | population = original.population.Select(cloner.Clone).ToList();
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[16560] | 241 | }
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| 242 |
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| 243 | if (original.offspringPopulation != null) {
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[16561] | 244 | offspringPopulation = original.offspringPopulation.Select(cloner.Clone).ToList();
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[16560] | 245 | }
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| 246 |
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| 247 | if (original.jointPopulation != null) {
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[16561] | 248 | jointPopulation = original.jointPopulation.Select(x => cloner.Clone(x)).ToList();
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[16560] | 249 | }
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| 250 |
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| 251 | if (original.executionContext != null) {
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| 252 | executionContext = cloner.Clone(original.executionContext);
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| 253 | }
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| 254 |
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| 255 | if (original.globalScope != null) {
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| 256 | globalScope = cloner.Clone(original.globalScope);
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| 257 | }
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| 258 | }
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| 259 |
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| 260 | [StorableConstructor]
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| 261 | protected MOEADAlgorithmBase(bool deserializing) : base(deserializing) { }
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| 262 | #endregion
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| 263 |
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| 264 | private void InitializePopulation(ExecutionContext executionContext, CancellationToken cancellationToken, IRandom random, bool[] maximization) {
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| 265 | var creator = Problem.SolutionCreator;
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| 266 | var evaluator = Problem.Evaluator;
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| 267 |
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| 268 | var dimensions = maximization.Length;
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| 269 | var populationSize = PopulationSize.Value;
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[16561] | 270 | population = new List<IMOEADSolution>(populationSize);
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[16560] | 271 |
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| 272 | var parentScope = executionContext.Scope;
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| 273 | // first, create all individuals
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| 274 | for (int i = 0; i < populationSize; ++i) {
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| 275 | var childScope = new Scope(i.ToString()) { Parent = parentScope };
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| 276 | ExecuteOperation(executionContext, cancellationToken, executionContext.CreateChildOperation(creator, childScope));
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| 277 | parentScope.SubScopes.Add(childScope);
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| 278 | }
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| 279 |
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| 280 | // then, evaluate them and update qualities
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| 281 | for (int i = 0; i < populationSize; ++i) {
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| 282 | var childScope = parentScope.SubScopes[i];
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| 283 | ExecuteOperation(executionContext, cancellationToken, executionContext.CreateChildOperation(evaluator, childScope));
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| 284 |
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| 285 | var qualities = (DoubleArray)childScope.Variables["Qualities"].Value;
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| 286 | var solution = new MOEADSolution(childScope, dimensions, 0);
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| 287 | for (int j = 0; j < dimensions; ++j) {
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| 288 | solution.Qualities[j] = maximization[j] ? 1 - qualities[j] : qualities[j];
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| 289 | }
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[16561] | 290 | population.Add(solution);
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[16560] | 291 | }
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| 292 | }
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| 293 |
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| 294 | public override void Prepare() {
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| 295 | base.Prepare();
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| 296 | }
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| 297 |
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[16583] | 298 | protected void InitializeAlgorithm(CancellationToken cancellationToken) {
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| 299 | globalScope = new Scope("Global Scope");
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| 300 | executionContext = new ExecutionContext(null, this, globalScope);
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| 301 |
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| 302 | // set the execution context for parameters to allow lookup
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| 303 | foreach (var parameter in Problem.Parameters.OfType<IValueParameter>()) {
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| 304 | // we need all of these in order for the wiring of the operators to work
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| 305 | globalScope.Variables.Add(new Variable(parameter.Name, parameter.Value));
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| 306 | }
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| 307 | globalScope.Variables.Add(new Variable("Results", Results)); // make results available as a parameter for analyzers etc.
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| 308 |
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| 309 | var rand = RandomParameter.Value;
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| 310 | if (SetSeedRandomly) Seed = RandomSeedGenerator.GetSeed();
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| 311 | rand.Reset(Seed);
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| 312 |
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| 313 | bool[] maximization = ((BoolArray)Problem.MaximizationParameter.ActualValue).CloneAsArray();
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| 314 | var dimensions = maximization.Length;
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| 315 |
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| 316 | var populationSize = PopulationSize.Value;
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| 317 |
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| 318 | InitializePopulation(executionContext, cancellationToken, rand, maximization);
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| 319 | InitializeUniformWeights(rand, populationSize, dimensions);
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| 320 | InitializeNeighbourHood(lambda, populationSize, NeighbourSize);
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| 321 |
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| 322 | IdealPoint = new double[dimensions];
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| 323 | IdealPoint.UpdateIdeal(population);
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| 324 |
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| 325 | NadirPoint = new double[dimensions];
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| 326 | NadirPoint.UpdateNadir(population);
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| 327 |
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| 328 | var functionTypeString = FunctionTypeParameter.Value.Value;
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| 329 | switch (functionTypeString) {
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| 330 | case "Chebyshev":
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| 331 | functionType = FunctionType.TCHE;
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| 332 | break;
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| 333 | case "PBI":
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| 334 | functionType = FunctionType.PBI;
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| 335 | break;
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| 336 | case "Weighted Sum":
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| 337 | functionType = FunctionType.AGG;
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| 338 | break;
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| 339 | }
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| 340 |
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| 341 | evaluatedSolutions = populationSize;
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| 342 | }
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| 343 |
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[16560] | 344 | protected override void Initialize(CancellationToken cancellationToken) {
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| 345 | globalScope = new Scope("Global Scope");
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| 346 | executionContext = new ExecutionContext(null, this, globalScope);
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| 347 |
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| 348 | // set the execution context for parameters to allow lookup
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| 349 | foreach (var parameter in Problem.Parameters.OfType<IValueParameter>()) {
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| 350 | // we need all of these in order for the wiring of the operators to work
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| 351 | globalScope.Variables.Add(new Variable(parameter.Name, parameter.Value));
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| 352 | }
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| 353 | globalScope.Variables.Add(new Variable("Results", Results)); // make results available as a parameter for analyzers etc.
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| 354 |
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| 355 | var rand = RandomParameter.Value;
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| 356 | if (SetSeedRandomly) Seed = RandomSeedGenerator.GetSeed();
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| 357 | rand.Reset(Seed);
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| 358 |
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| 359 | bool[] maximization = ((BoolArray)Problem.MaximizationParameter.ActualValue).CloneAsArray();
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| 360 | var dimensions = maximization.Length;
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| 361 |
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| 362 | var populationSize = PopulationSize.Value;
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| 363 |
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| 364 | InitializePopulation(executionContext, cancellationToken, rand, maximization);
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| 365 | InitializeUniformWeights(rand, populationSize, dimensions);
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| 366 | InitializeNeighbourHood(lambda, populationSize, NeighbourSize);
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| 367 |
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| 368 | IdealPoint = new double[dimensions];
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| 369 | IdealPoint.UpdateIdeal(population);
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| 370 |
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| 371 | NadirPoint = new double[dimensions];
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| 372 | NadirPoint.UpdateNadir(population);
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| 373 |
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| 374 | var functionTypeString = FunctionTypeParameter.Value.Value;
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| 375 | switch (functionTypeString) {
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| 376 | case "Chebyshev":
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| 377 | functionType = FunctionType.TCHE;
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| 378 | break;
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| 379 | case "PBI":
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| 380 | functionType = FunctionType.PBI;
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| 381 | break;
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| 382 | case "Weighted Sum":
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| 383 | functionType = FunctionType.AGG;
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| 384 | break;
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| 385 | }
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| 386 |
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| 387 | evaluatedSolutions = populationSize;
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| 388 |
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| 389 | base.Initialize(cancellationToken);
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| 390 | }
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| 391 |
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| 392 | public override bool SupportsPause => true;
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| 393 |
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| 394 | protected void InitializeUniformWeights(IRandom random, int populationSize, int dimensions) {
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[16583] | 395 | lambda = Enumerable.Range(0, populationSize).Select(_ => GenerateSample(random, dimensions)).ToArray();
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| 396 | }
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[16560] | 397 |
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[16583] | 398 | // implements random number generation from https://en.wikipedia.org/wiki/Dirichlet_distribution#Random_number_generation
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| 399 | private double[] GenerateSample(IRandom random, int dim) {
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| 400 | var sum = 0d;
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| 401 | var sample = new double[dim];
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| 402 | for (int i = 0; i < dim; ++i) {
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| 403 | sample[i] = GammaDistributedRandom.NextDouble(random, 1, 1);
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| 404 | sum += sample[i];
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[16560] | 405 | }
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[16583] | 406 | for (int i = 0; i < dim; ++i) {
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| 407 | sample[i] /= sum;
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| 408 | }
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| 409 | return sample;
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[16560] | 410 | }
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| 411 |
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| 412 | protected void InitializeNeighbourHood(double[][] lambda, int populationSize, int neighbourSize) {
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| 413 | neighbourhood = new int[populationSize][];
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| 414 |
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| 415 | var x = new double[populationSize];
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| 416 | var idx = new int[populationSize];
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| 417 |
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| 418 | for (int i = 0; i < populationSize; ++i) {
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| 419 | for (int j = 0; j < populationSize; ++j) {
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| 420 | x[j] = MOEADUtil.EuclideanDistance(lambda[i], lambda[j]);
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| 421 | idx[j] = j;
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| 422 | }
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| 423 |
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| 424 | MOEADUtil.MinFastSort(x, idx, populationSize, neighbourSize);
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| 425 | neighbourhood[i] = (int[])idx.Clone();
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| 426 | }
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| 427 | }
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| 428 |
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| 429 | protected NeighborType ChooseNeighborType(IRandom random, double neighbourhoodSelectionProbability) {
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| 430 | return random.NextDouble() < neighbourhoodSelectionProbability
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| 431 | ? NeighborType.NEIGHBOR
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| 432 | : NeighborType.POPULATION;
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| 433 | }
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| 434 |
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| 435 | protected IList<IMOEADSolution> ParentSelection(IRandom random, int subProblemId, NeighborType neighbourType) {
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| 436 | List<int> matingPool = MatingSelection(random, subProblemId, 2, neighbourType);
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| 437 |
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| 438 | var parents = new IMOEADSolution[3];
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| 439 |
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| 440 | parents[0] = population[matingPool[0]];
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| 441 | parents[1] = population[matingPool[1]];
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| 442 | parents[2] = population[subProblemId];
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| 443 |
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| 444 | return parents;
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| 445 | }
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| 446 |
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| 447 | protected List<int> MatingSelection(IRandom random, int subproblemId, int numberOfSolutionsToSelect, NeighborType neighbourType) {
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| 448 | int populationSize = PopulationSize.Value;
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| 449 |
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| 450 | var listOfSolutions = new List<int>(numberOfSolutionsToSelect);
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| 451 |
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| 452 | int neighbourSize = neighbourhood[subproblemId].Length;
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| 453 | while (listOfSolutions.Count < numberOfSolutionsToSelect) {
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| 454 | var selectedSolution = neighbourType == NeighborType.NEIGHBOR
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| 455 | ? neighbourhood[subproblemId][random.Next(neighbourSize)]
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| 456 | : random.Next(populationSize);
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| 457 |
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| 458 | bool flag = true;
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| 459 | foreach (int individualId in listOfSolutions) {
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| 460 | if (individualId == selectedSolution) {
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| 461 | flag = false;
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| 462 | break;
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| 463 | }
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| 464 | }
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| 465 |
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| 466 | if (flag) {
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| 467 | listOfSolutions.Add(selectedSolution);
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| 468 | }
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| 469 | }
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| 470 |
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| 471 | return listOfSolutions;
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| 472 | }
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| 473 |
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| 474 | protected void UpdateNeighbourHood(IRandom random, IMOEADSolution individual, int subProblemId, NeighborType neighbourType) {
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| 475 | int replacedSolutions = 0;
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| 476 | int size = neighbourType == NeighborType.NEIGHBOR ? NeighbourSize : population.Count;
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| 477 |
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| 478 | foreach (var i in Enumerable.Range(0, size).Shuffle(random)) {
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| 479 | int k = neighbourType == NeighborType.NEIGHBOR
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| 480 | ? neighbourhood[subProblemId][i]
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| 481 | : i;
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| 482 |
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| 483 | double f1 = CalculateFitness(population[k].Qualities, lambda[k]);
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| 484 | double f2 = CalculateFitness(individual.Qualities, lambda[k]);
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| 485 |
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| 486 | if (f2 < f1) {
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| 487 | population[k] = (IMOEADSolution)individual.Clone();
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| 488 | replacedSolutions++;
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| 489 | }
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| 490 |
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| 491 | if (replacedSolutions >= MaximumNumberOfReplacedSolutions) {
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| 492 | return;
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| 493 | }
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| 494 | }
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| 495 | }
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| 496 |
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| 497 | private double CalculateFitness(double[] qualities, double[] lambda) {
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| 498 | double fitness;
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| 499 | int dim = qualities.Length;
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| 500 | switch (functionType) {
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| 501 | case FunctionType.TCHE: {
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[16583] | 502 | double maxFun = double.MinValue;
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[16560] | 503 |
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| 504 | for (int n = 0; n < dim; n++) {
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| 505 | double diff = Math.Abs(qualities[n] - IdealPoint[n]);
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| 506 |
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[16583] | 507 | var l = lambda[n].IsAlmost(0) ? 0.0001 : lambda[n];
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| 508 | //var feval = l * diff;
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| 509 | // introduce objective scaling
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| 510 | var feval = l * (qualities[n] - IdealPoint[n]) / (NadirPoint[n] - IdealPoint[n]);
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[16560] | 511 | if (feval > maxFun) {
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| 512 | maxFun = feval;
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| 513 | }
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| 514 | }
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| 515 |
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| 516 | fitness = maxFun;
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| 517 | return fitness;
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| 518 | }
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| 519 | case FunctionType.AGG: {
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| 520 | double sum = 0.0;
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| 521 | for (int n = 0; n < dim; n++) {
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| 522 | sum += lambda[n] * qualities[n];
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| 523 | }
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| 524 |
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| 525 | fitness = sum;
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| 526 | return fitness;
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| 527 | }
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| 528 | case FunctionType.PBI: {
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| 529 | double d1, d2, nl;
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| 530 | double theta = 5.0;
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| 531 | int dimensions = dim;
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| 532 |
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| 533 | d1 = d2 = nl = 0.0;
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| 534 |
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| 535 | for (int i = 0; i < dimensions; i++) {
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| 536 | d1 += (qualities[i] - IdealPoint[i]) * lambda[i];
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| 537 | nl += Math.Pow(lambda[i], 2.0);
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| 538 | }
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| 539 | nl = Math.Sqrt(nl);
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| 540 | d1 = Math.Abs(d1) / nl;
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| 541 |
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| 542 | for (int i = 0; i < dimensions; i++) {
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| 543 | d2 += Math.Pow((qualities[i] - IdealPoint[i]) - d1 * (lambda[i] / nl), 2.0);
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| 544 | }
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| 545 | d2 = Math.Sqrt(d2);
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| 546 |
|
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| 547 | fitness = (d1 + theta * d2);
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| 548 | return fitness;
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| 549 | }
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| 550 | default: {
|
---|
| 551 | throw new ArgumentException($"Unknown function type: {functionType}");
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| 552 | }
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| 553 | }
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| 554 | }
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| 555 |
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| 556 | public IList<IMOEADSolution> GetResult(IRandom random) {
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---|
| 557 | var populationSize = PopulationSize.Value;
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| 558 | var resultPopulationSize = ResultPopulationSize.Value;
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| 559 |
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| 560 | if (populationSize > resultPopulationSize) {
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| 561 | return MOEADUtil.GetSubsetOfEvenlyDistributedSolutions(random, population, resultPopulationSize);
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| 562 | } else {
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| 563 | return population;
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| 564 | }
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---|
| 565 | }
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---|
| 566 |
|
---|
| 567 | protected void UpdateParetoFronts() {
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---|
| 568 | bool dominates(Point2D<double> x, Point2D<double> y) => x.X <= y.X && x.Y <= y.Y;
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---|
| 569 | // get all non-dominated points
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| 570 | var points = population.Select(x => new Point2D<double>(Math.Round(x.Qualities[0], 6), Math.Round(x.Qualities[1], 6))).OrderBy(_ => _.X).ThenBy(_ => _.Y).ToArray();
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| 571 | var dominated = new bool[points.Length];
|
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| 572 |
|
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| 573 | for (int i = 0; i < points.Length; ++i) {
|
---|
| 574 | if (dominated[i]) { continue; }
|
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| 575 | for (int j = 0; j < points.Length; ++j) {
|
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| 576 | if (i == j) { continue; }
|
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| 577 | if (dominated[j]) { continue; }
|
---|
| 578 | dominated[j] = dominates(points[i], points[j]);
|
---|
| 579 | }
|
---|
| 580 | }
|
---|
| 581 |
|
---|
| 582 | var pf = Enumerable.Range(0, dominated.Length).Where(x => !dominated[x]).Select(x => points[x]);
|
---|
| 583 |
|
---|
| 584 | ScatterPlot sp;
|
---|
| 585 | if (!Results.ContainsKey("Pareto Front")) {
|
---|
| 586 | sp = new ScatterPlot();
|
---|
| 587 | sp.Rows.Add(new ScatterPlotDataRow("Pareto Front", "", pf) { VisualProperties = { PointSize = 5 } });
|
---|
| 588 | Results.AddOrUpdateResult("Pareto Front", sp);
|
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| 589 | } else {
|
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| 590 | sp = (ScatterPlot)Results["Pareto Front"].Value;
|
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| 591 | sp.Rows["Pareto Front"].Points.Replace(pf);
|
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| 592 | }
|
---|
| 593 | }
|
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| 594 |
|
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| 595 | #region operator wiring and events
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| 596 | protected void ExecuteOperation(ExecutionContext executionContext, CancellationToken cancellationToken, IOperation operation) {
|
---|
| 597 | Stack<IOperation> executionStack = new Stack<IOperation>();
|
---|
| 598 | executionStack.Push(operation);
|
---|
| 599 | while (executionStack.Count > 0) {
|
---|
| 600 | cancellationToken.ThrowIfCancellationRequested();
|
---|
| 601 | IOperation next = executionStack.Pop();
|
---|
| 602 | if (next is OperationCollection) {
|
---|
| 603 | OperationCollection coll = (OperationCollection)next;
|
---|
| 604 | for (int i = coll.Count - 1; i >= 0; i--)
|
---|
| 605 | if (coll[i] != null) executionStack.Push(coll[i]);
|
---|
| 606 | } else if (next is IAtomicOperation) {
|
---|
| 607 | IAtomicOperation op = (IAtomicOperation)next;
|
---|
| 608 | next = op.Operator.Execute((IExecutionContext)op, cancellationToken);
|
---|
| 609 | if (next != null) executionStack.Push(next);
|
---|
| 610 | }
|
---|
| 611 | }
|
---|
| 612 | }
|
---|
| 613 |
|
---|
| 614 | private void UpdateAnalyzers() {
|
---|
| 615 | Analyzer.Operators.Clear();
|
---|
| 616 | if (Problem != null) {
|
---|
| 617 | foreach (IAnalyzer analyzer in Problem.Operators.OfType<IAnalyzer>()) {
|
---|
| 618 | foreach (IScopeTreeLookupParameter param in analyzer.Parameters.OfType<IScopeTreeLookupParameter>())
|
---|
| 619 | param.Depth = 1;
|
---|
| 620 | Analyzer.Operators.Add(analyzer, analyzer.EnabledByDefault);
|
---|
| 621 | }
|
---|
| 622 | }
|
---|
| 623 | }
|
---|
| 624 |
|
---|
| 625 | private void UpdateCrossovers() {
|
---|
| 626 | ICrossover oldCrossover = CrossoverParameter.Value;
|
---|
| 627 | CrossoverParameter.ValidValues.Clear();
|
---|
| 628 | ICrossover defaultCrossover = Problem.Operators.OfType<ICrossover>().FirstOrDefault();
|
---|
| 629 |
|
---|
| 630 | foreach (ICrossover crossover in Problem.Operators.OfType<ICrossover>().OrderBy(x => x.Name))
|
---|
| 631 | CrossoverParameter.ValidValues.Add(crossover);
|
---|
| 632 |
|
---|
| 633 | if (oldCrossover != null) {
|
---|
| 634 | ICrossover crossover = CrossoverParameter.ValidValues.FirstOrDefault(x => x.GetType() == oldCrossover.GetType());
|
---|
| 635 | if (crossover != null) CrossoverParameter.Value = crossover;
|
---|
| 636 | else oldCrossover = null;
|
---|
| 637 | }
|
---|
| 638 | if (oldCrossover == null && defaultCrossover != null)
|
---|
| 639 | CrossoverParameter.Value = defaultCrossover;
|
---|
| 640 | }
|
---|
| 641 |
|
---|
| 642 | private void UpdateMutators() {
|
---|
| 643 | IManipulator oldMutator = MutatorParameter.Value;
|
---|
| 644 | MutatorParameter.ValidValues.Clear();
|
---|
| 645 | IManipulator defaultMutator = Problem.Operators.OfType<IManipulator>().FirstOrDefault();
|
---|
| 646 |
|
---|
| 647 | foreach (IManipulator mutator in Problem.Operators.OfType<IManipulator>().OrderBy(x => x.Name))
|
---|
| 648 | MutatorParameter.ValidValues.Add(mutator);
|
---|
| 649 |
|
---|
| 650 | if (oldMutator != null) {
|
---|
| 651 | IManipulator mutator = MutatorParameter.ValidValues.FirstOrDefault(x => x.GetType() == oldMutator.GetType());
|
---|
| 652 | if (mutator != null) MutatorParameter.Value = mutator;
|
---|
| 653 | else oldMutator = null;
|
---|
| 654 | }
|
---|
| 655 |
|
---|
| 656 | if (oldMutator == null && defaultMutator != null)
|
---|
| 657 | MutatorParameter.Value = defaultMutator;
|
---|
| 658 | }
|
---|
| 659 |
|
---|
| 660 | protected override void OnProblemChanged() {
|
---|
| 661 | UpdateCrossovers();
|
---|
| 662 | UpdateMutators();
|
---|
| 663 | UpdateAnalyzers();
|
---|
| 664 | base.OnProblemChanged();
|
---|
| 665 | }
|
---|
| 666 |
|
---|
[16583] | 667 | protected override void OnExecutionStateChanged() {
|
---|
| 668 | previousExecutionState = ExecutionState;
|
---|
| 669 | base.OnExecutionStateChanged();
|
---|
| 670 | }
|
---|
| 671 |
|
---|
[16560] | 672 | protected override void OnStopped() {
|
---|
| 673 | if (solutions != null) {
|
---|
| 674 | solutions.Clear();
|
---|
| 675 | }
|
---|
| 676 | if (population != null) {
|
---|
| 677 | population.Clear();
|
---|
| 678 | }
|
---|
| 679 | if (offspringPopulation != null) {
|
---|
| 680 | offspringPopulation.Clear();
|
---|
| 681 | }
|
---|
| 682 | if (jointPopulation != null) {
|
---|
| 683 | jointPopulation.Clear();
|
---|
| 684 | }
|
---|
[16583] | 685 | executionContext.Scope.SubScopes.Clear();
|
---|
[16560] | 686 | base.OnStopped();
|
---|
| 687 | }
|
---|
| 688 | #endregion
|
---|
| 689 | }
|
---|
| 690 | }
|
---|