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source: stable/HeuristicLab.Problems.TestFunctions/3.3/Evaluators/ZakharovEvaluator.cs @ 9990

Last change on this file since 9990 was 9990, checked in by abeham, 9 years ago

#1909: merged into stable branch

File size: 4.4 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using HeuristicLab.Common;
23using HeuristicLab.Core;
24using HeuristicLab.Data;
25using HeuristicLab.Encodings.RealVectorEncoding;
26using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
27
28namespace HeuristicLab.Problems.TestFunctions {
29  /// <summary>
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.
31  /// </summary>
32  [Item("ZakharovEvaluator", "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.")]
33  [StorableClass]
34  public class ZakharovEvaluator : SingleObjectiveTestFunctionProblemEvaluator {
35    public override string FunctionName { get { return "Zakharov"; } }
36    /// <summary>
37    /// Returns false as the Zakharov function is a minimization problem.
38    /// </summary>
39    public override bool Maximization {
40      get { return false; }
41    }
42    /// <summary>
43    /// Gets the optimum function value (0).
44    /// </summary>
45    public override double BestKnownQuality {
46      get { return 0; }
47    }
48    /// <summary>
49    /// Gets the lower and upper bound of the function.
50    /// </summary>
51    public override DoubleMatrix Bounds {
52      get { return new DoubleMatrix(new double[,] { { -5, 10 } }); }
53    }
54    /// <summary>
55    /// Gets the minimum problem size (1).
56    /// </summary>
57    public override int MinimumProblemSize {
58      get { return 1; }
59    }
60    /// <summary>
61    /// Gets the (theoretical) maximum problem size (2^31 - 1).
62    /// </summary>
63    public override int MaximumProblemSize {
64      get { return int.MaxValue; }
65    }
66
67    public override RealVector GetBestKnownSolution(int dimension) {
68      return new RealVector(dimension);
69    }
70
71    [StorableConstructor]
72    protected ZakharovEvaluator(bool deserializing) : base(deserializing) { }
73    protected ZakharovEvaluator(ZakharovEvaluator original, Cloner cloner) : base(original, cloner) { }
74    public ZakharovEvaluator() : base() { }
75
76    public override IDeepCloneable Clone(Cloner cloner) {
77      return new ZakharovEvaluator(this, cloner);
78    }
79
80    /// <summary>
81    /// Evaluates the test function for a specific <paramref name="point"/>.
82    /// </summary>
83    /// <param name="point">N-dimensional point for which the test function should be evaluated.</param>
84    /// <returns>The result value of the Zakharov function at the given point.</returns>
85    public static double Apply(RealVector point) {
86      int length = point.Length;
87      double s1 = 0;
88      double s2 = 0;
89
90      for (int i = 0; i < length; i++) {
91        s1 += point[i] * point[i];
92        s2 += 0.5 * i * point[i];
93      }
94      return s1 + (s2 * s2) + (s2 * s2 * s2 * s2);
95    }
96
97    /// <summary>
98    /// Evaluates the test function for a specific <paramref name="point"/>.
99    /// </summary>
100    /// <remarks>Calls <see cref="Apply"/>.</remarks>
101    /// <param name="point">N-dimensional point for which the test function should be evaluated.</param>
102    /// <returns>The result value of the Zakharov function at the given point.</returns>
103    public override double Evaluate(RealVector point) {
104      return Apply(point);
105    }
106  }
107}
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