1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022013 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 


22  using HeuristicLab.Common;


23  using HeuristicLab.Core;


24  using HeuristicLab.Data;


25  using HeuristicLab.Encodings.RealVectorEncoding;


26  using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;


27 


28  namespace 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. 291308, 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. 291308, 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">Ndimensional 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">Ndimensional 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  }

