1 | #region License Information |
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2 | /* HeuristicLab |
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3 | * Copyright (C) 2002-2015 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 HeuristicLab.Common; |
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23 | using HeuristicLab.Core; |
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24 | using HeuristicLab.Data; |
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25 | using HeuristicLab.Encodings.RealVectorEncoding; |
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26 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable; |
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27 | |
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28 | namespace HeuristicLab.Problems.TestFunctions { |
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29 | /// <summary> |
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30 | /// The Zakharov function is implemented as described in Hedar, A. & Fukushima, M. 2004. Heuristic pattern search and its hybridization with simulated annealing for nonlinear global optimization. Optimization Methods and Software 19, pp. 291-308, Taylor & Francis. |
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31 | /// </summary> |
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32 | [Item("Zakharov", "Evaluates the Zakharov function on a given point. The optimum of this function is 0 at the origin. It is implemented as described in Hedar, A. & Fukushima, M. 2004. Heuristic pattern search and its hybridization with simulated annealing for nonlinear global optimization. Optimization Methods and Software 19, pp. 291-308, Taylor & Francis.")] |
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33 | [StorableClass] |
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34 | public class Zakharov : SingleObjectiveTestFunction { |
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35 | /// <summary> |
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36 | /// Returns false as the Zakharov function is a minimization problem. |
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37 | /// </summary> |
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38 | public override bool Maximization { |
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39 | get { return false; } |
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40 | } |
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41 | /// <summary> |
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42 | /// Gets the optimum function value (0). |
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43 | /// </summary> |
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44 | public override double BestKnownQuality { |
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45 | get { return 0; } |
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46 | } |
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47 | /// <summary> |
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48 | /// Gets the lower and upper bound of the function. |
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49 | /// </summary> |
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50 | public override DoubleMatrix Bounds { |
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51 | get { return new DoubleMatrix(new double[,] { { -5, 10 } }); } |
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52 | } |
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53 | /// <summary> |
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54 | /// Gets the minimum problem size (1). |
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55 | /// </summary> |
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56 | public override int MinimumProblemSize { |
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57 | get { return 1; } |
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58 | } |
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59 | /// <summary> |
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60 | /// Gets the (theoretical) maximum problem size (2^31 - 1). |
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61 | /// </summary> |
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62 | public override int MaximumProblemSize { |
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63 | get { return int.MaxValue; } |
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64 | } |
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65 | |
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66 | public override RealVector GetBestKnownSolution(int dimension) { |
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67 | return new RealVector(dimension); |
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68 | } |
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69 | |
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70 | [StorableConstructor] |
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71 | protected Zakharov(bool deserializing) : base(deserializing) { } |
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72 | protected Zakharov(Zakharov original, Cloner cloner) : base(original, cloner) { } |
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73 | public Zakharov() : base() { } |
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74 | |
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75 | public override IDeepCloneable Clone(Cloner cloner) { |
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76 | return new Zakharov(this, cloner); |
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77 | } |
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78 | |
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79 | /// <summary> |
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80 | /// Evaluates the test function for a specific <paramref name="point"/>. |
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81 | /// </summary> |
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82 | /// <param name="point">N-dimensional point for which the test function should be evaluated.</param> |
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83 | /// <returns>The result value of the Zakharov function at the given point.</returns> |
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84 | public static double Apply(RealVector point) { |
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85 | int length = point.Length; |
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86 | double s1 = 0; |
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87 | double s2 = 0; |
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88 | |
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89 | for (int i = 0; i < length; i++) { |
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90 | s1 += point[i] * point[i]; |
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91 | s2 += 0.5 * i * point[i]; |
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92 | } |
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93 | return s1 + (s2 * s2) + (s2 * s2 * s2 * s2); |
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94 | } |
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95 | |
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96 | /// <summary> |
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97 | /// Evaluates the test function for a specific <paramref name="point"/>. |
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98 | /// </summary> |
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99 | /// <remarks>Calls <see cref="Apply"/>.</remarks> |
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100 | /// <param name="point">N-dimensional point for which the test function should be evaluated.</param> |
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101 | /// <returns>The result value of the Zakharov function at the given point.</returns> |
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102 | public override double Evaluate(RealVector point) { |
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103 | return Apply(point); |
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104 | } |
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105 | } |
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106 | } |
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