1 | #region License Information
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2 | /* HeuristicLab
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3 | * Copyright (C) 2002-2010 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.Core;
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24 | using HeuristicLab.Data;
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25 | using HeuristicLab.Parameters;
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26 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
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27 |
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28 | namespace HeuristicLab.Encodings.RealVectorEncoding {
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29 | /// <summary>
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30 | /// The solution is manipulated with diminishing strength over time. In addition the mutated value is not sampled over the entire domain, but additive at the selected position.<br/>
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31 | /// Initially, the space will be searched uniformly and very locally at later stages. This increases the probability of generating the new number closer to the current value.
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32 | /// </summary>
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33 | /// <remarks>
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34 | /// It is implemented as described in Michalewicz, Z. 1999. Genetic Algorithms + Data Structures = Evolution Programs. Third, Revised and Extended Edition, Spring-Verlag Berlin Heidelberg.
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35 | /// </remarks>
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36 | [Item("MichalewiczNonUniformOnePositionManipulator", "It is implemented as described in Michalewicz, Z. 1999. Genetic Algorithms + Data Structures = Evolution Programs. Third, Revised and Extended Edition, Spring-Verlag Berlin Heidelberg.")]
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37 | [StorableClass]
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38 | public class MichalewiczNonUniformOnePositionManipulator : RealVectorManipulator {
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39 | /// <summary>
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40 | /// The lower and upper bound (1st and 2nd column) of the positions in the vector. If there are less rows than dimensions, the rows are cycled.
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41 | /// </summary>
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42 | public ValueLookupParameter<DoubleMatrix> BoundsParameter {
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43 | get { return (ValueLookupParameter<DoubleMatrix>)Parameters["Bounds"]; }
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44 | }
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45 | /// <summary>
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46 | /// The current generation.
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47 | /// </summary>
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48 | public LookupParameter<IntValue> GenerationParameter {
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49 | get { return (LookupParameter<IntValue>)Parameters["Generation"]; }
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50 | }
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51 | /// <summary>
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52 | /// The maximum generation.
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53 | /// </summary>
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54 | public LookupParameter<IntValue> MaximumGenerationsParameter {
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55 | get { return (LookupParameter<IntValue>)Parameters["MaximumGenerations"]; }
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56 | }
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57 | /// <summary>
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58 | /// The parameter describing how much the mutation should depend on the progress towards the maximum generation.
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59 | /// </summary>
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60 | public ValueLookupParameter<DoubleValue> GenerationDependencyParameter {
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61 | get { return (ValueLookupParameter<DoubleValue>)Parameters["GenerationDependency"]; }
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62 | }
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63 |
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64 | /// <summary>
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65 | /// Initializes a new instance of <see cref="MichalewiczNonUniformOnePositionManipulator"/> with four
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66 | /// parameters (<c>Bounds</c>, <c>CurrentGeneration</c>, <c>MaximumGenerations</c>
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67 | /// and <c>GenerationDependency</c>).
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68 | /// </summary>
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69 | public MichalewiczNonUniformOnePositionManipulator()
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70 | : base() {
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71 | Parameters.Add(new ValueLookupParameter<DoubleMatrix>("Bounds", "The lower and upper bound (1st and 2nd column) of the positions in the vector. If there are less rows than dimensions, the rows are cycled."));
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72 | Parameters.Add(new LookupParameter<IntValue>("Generation", "Current generation of the algorithm"));
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73 | Parameters.Add(new LookupParameter<IntValue>("MaximumGenerations", "Maximum number of generations"));
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74 | Parameters.Add(new ValueLookupParameter<DoubleValue>("GenerationDependency", "Specifies the degree of dependency on the number of generations", new DoubleValue(5)));
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75 | }
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76 |
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77 | /// <summary>
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78 | /// Performs a non uniformly distributed one position manipulation on the given
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79 | /// real <paramref name="vector"/>. The probability of stronger mutations reduces the more <see cref="currentGeneration"/> approaches <see cref="maximumGenerations"/>.
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80 | /// </summary>
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81 | /// <exception cref="ArgumentException">Thrown when <paramref name="currentGeneration"/> is greater than <paramref name="maximumGenerations"/>.</exception>
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82 | /// <param name="random">The random number generator.</param>
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83 | /// <param name="vector">The real vector to manipulate.</param>
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84 | /// <param name="bounds">The lower and upper bound (1st and 2nd column) of the positions in the vector. If there are less rows than dimensions, the rows are cycled.</param>
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85 | /// <param name="currentGeneration">The current generation of the algorithm.</param>
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86 | /// <param name="maximumGenerations">Maximum number of generations.</param>
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87 | /// <param name="generationsDependency">Specifies the degree of dependency on the number of generations.</param>
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88 | /// <returns>The manipulated real vector.</returns>
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89 | public static void Apply(IRandom random, RealVector vector, DoubleMatrix bounds, IntValue currentGeneration, IntValue maximumGenerations, DoubleValue generationsDependency) {
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90 | if (currentGeneration.Value > maximumGenerations.Value) throw new ArgumentException("MichalewiczNonUniformOnePositionManipulator: CurrentGeneration must be smaller or equal than MaximumGeneration", "currentGeneration");
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91 | int length = vector.Length;
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92 | int index = random.Next(length);
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93 |
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94 | double prob = (1 - Math.Pow(random.NextDouble(), Math.Pow(1 - currentGeneration.Value / maximumGenerations.Value, generationsDependency.Value)));
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95 |
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96 | double min = bounds[index % bounds.Rows, 0];
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97 | double max = bounds[index % bounds.Rows, 1];
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98 |
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99 | if (random.NextDouble() < 0.5) {
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100 | vector[index] = vector[index] + (max - vector[index]) * prob;
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101 | } else {
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102 | vector[index] = vector[index] - (vector[index] - min) * prob;
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103 | }
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104 | }
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105 |
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106 | /// <summary>
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107 | /// Checks if all parameters are available and forwards the call to <see cref="Apply(IRandom, RealVector, DoubleValue, DoubleValue, IntValue, IntValue, DoubleValue)"/>.
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108 | /// </summary>
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109 | /// <param name="random">The random number generator.</param>
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110 | /// <param name="realVector">The real vector that should be manipulated.</param>
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111 | protected override void Manipulate(IRandom random, RealVector realVector) {
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112 | if (BoundsParameter.ActualValue == null) throw new InvalidOperationException("MichalewiczNonUniformOnePositionManipulator: Parameter " + BoundsParameter.ActualName + " could not be found.");
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113 | if (GenerationParameter.ActualValue == null) throw new InvalidOperationException("MichalewiczNonUniformOnePositionManipulator: Parameter " + GenerationParameter.ActualName + " could not be found.");
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114 | if (MaximumGenerationsParameter.ActualValue == null) throw new InvalidOperationException("MichalewiczNonUniformOnePositionManipulator: Parameter " + MaximumGenerationsParameter.ActualName + " could not be found.");
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115 | if (GenerationDependencyParameter.ActualValue == null) throw new InvalidOperationException("MichalewiczNonUniformOnePositionManipulator: Parameter " + GenerationDependencyParameter.ActualName + " could not be found.");
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116 | Apply(random, realVector, BoundsParameter.ActualValue, GenerationParameter.ActualValue, MaximumGenerationsParameter.ActualValue, GenerationDependencyParameter.ActualValue);
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117 | }
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118 | }
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119 | }
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