source: branches/ProblemRefactoring/HeuristicLab.Problems.TestFunctions/3.3/Functions/Zakharov.cs @ 13403

Last change on this file since 13403 was 13403, checked in by abeham, 4 years ago

#2521:

  • Adapted single-objective test function problem to new problem infrastructure
  • Added additional interfaces to RealVectorEncoding
  • Fixed IParticleUpdater interface (must implement IStochasticOperator if it contains a Random parameter)
File size: 4.2 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2015 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("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.")]
33  [StorableClass]
34  public class Zakharov : SingleObjectiveTestFunction {
35    /// <summary>
36    /// Returns false as the Zakharov function is a minimization problem.
37    /// </summary>
38    public override bool Maximization {
39      get { return false; }
40    }
41    /// <summary>
42    /// Gets the optimum function value (0).
43    /// </summary>
44    public override double BestKnownQuality {
45      get { return 0; }
46    }
47    /// <summary>
48    /// Gets the lower and upper bound of the function.
49    /// </summary>
50    public override DoubleMatrix Bounds {
51      get { return new DoubleMatrix(new double[,] { { -5, 10 } }); }
52    }
53    /// <summary>
54    /// Gets the minimum problem size (1).
55    /// </summary>
56    public override int MinimumProblemSize {
57      get { return 1; }
58    }
59    /// <summary>
60    /// Gets the (theoretical) maximum problem size (2^31 - 1).
61    /// </summary>
62    public override int MaximumProblemSize {
63      get { return int.MaxValue; }
64    }
65
66    public override RealVector GetBestKnownSolution(int dimension) {
67      return new RealVector(dimension);
68    }
69
70    [StorableConstructor]
71    protected Zakharov(bool deserializing) : base(deserializing) { }
72    protected Zakharov(Zakharov original, Cloner cloner) : base(original, cloner) { }
73    public Zakharov() : base() { }
74
75    public override IDeepCloneable Clone(Cloner cloner) {
76      return new Zakharov(this, cloner);
77    }
78
79    /// <summary>
80    /// Evaluates the test function for a specific <paramref name="point"/>.
81    /// </summary>
82    /// <param name="point">N-dimensional point for which the test function should be evaluated.</param>
83    /// <returns>The result value of the Zakharov function at the given point.</returns>
84    public static double Apply(RealVector point) {
85      int length = point.Length;
86      double s1 = 0;
87      double s2 = 0;
88
89      for (int i = 0; i < length; i++) {
90        s1 += point[i] * point[i];
91        s2 += 0.5 * i * point[i];
92      }
93      return s1 + (s2 * s2) + (s2 * s2 * s2 * s2);
94    }
95
96    /// <summary>
97    /// Evaluates the test function for a specific <paramref name="point"/>.
98    /// </summary>
99    /// <remarks>Calls <see cref="Apply"/>.</remarks>
100    /// <param name="point">N-dimensional point for which the test function should be evaluated.</param>
101    /// <returns>The result value of the Zakharov function at the given point.</returns>
102    public override double Evaluate(RealVector point) {
103      return Apply(point);
104    }
105  }
106}
Note: See TracBrowser for help on using the repository browser.