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 System;


23  using HeuristicLab.Common;


24  using HeuristicLab.Core;


25  using HeuristicLab.Data;


26  using HeuristicLab.Parameters;


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


28 


29  namespace HeuristicLab.Encodings.RealVectorEncoding {


30  /// <summary>


31  /// Performs the polynomial manipulation on all positions in the real vector.


32  /// </summary>


33  /// <remarks>


34  /// The polynomial manipulation is implemented as described in Deb, K. & Goyal, M. A. 1996. Combined Genetic Adaptive Search (GeneAS) for Engineering Design Computer Science and Informatics, 26, pp. 3045.


35  /// It is performed on all positions of a real vector.


36  /// </remarks>


37  [Item("PolynomialAllPositionManipulator", "The polynomial manipulation is implemented as described in Deb, K. & Goyal, M. A. 1996. Combined Genetic Adaptive Search (GeneAS) for Engineering Design Computer Science and Informatics, 26, pp. 3045. In this operator it is performed on all positions of the real vector.")]


38  [StorableClass]


39  public class PolynomialAllPositionManipulator : RealVectorManipulator {


40  /// <summary>


41  /// The contiguity parameter specifies the shape of the probability density function that controls the mutation. Setting it to 0 is similar to a uniform distribution over the entire manipulation range (specified by <see cref="MaximumManipulationParameter"/>.


42  /// A higher value will shape the density function such that values closer to 0 (little manipulation) are more likely than larger values.


43  /// </summary>


44  public ValueLookupParameter<DoubleValue> ContiguityParameter {


45  get { return (ValueLookupParameter<DoubleValue>)Parameters["Contiguity"]; }


46  }


47  /// <summary>


48  /// The maximum manipulation parameter specifies the range of the manipulation. The value specified here is the highest value the mutation will ever add to the current value.


49  /// </summary>


50  /// <remarks>


51  /// If there are bounds specified the manipulated value is restricted by the given lower and upper bounds.


52  /// </remarks>


53  public ValueLookupParameter<DoubleValue> MaximumManipulationParameter {


54  get { return (ValueLookupParameter<DoubleValue>)Parameters["MaximumManipulation"]; }


55  }


56 


57  [StorableConstructor]


58  protected PolynomialAllPositionManipulator(bool deserializing) : base(deserializing) { }


59  protected PolynomialAllPositionManipulator(PolynomialAllPositionManipulator original, Cloner cloner) : base(original, cloner) { }


60  /// <summary>


61  /// Initializes a new instance of <see cref="PolynomialAllPositionManipulator"/> with two parameters


62  /// (<c>Contiguity</c> and <c>MaximumManipulation</c>).


63  /// </summary>


64  public PolynomialAllPositionManipulator()


65  : base() {


66  Parameters.Add(new ValueLookupParameter<DoubleValue>("Contiguity", "Specifies whether the manipulation should produce far stretching (small value) or close (large value) manipulations with higher probability. Valid values must be greater or equal to 0.", new DoubleValue(2)));


67  Parameters.Add(new ValueLookupParameter<DoubleValue>("MaximumManipulation", "Specifies the maximum value that should be added or subtracted by the manipulation. If this value is set to 0 no mutation will be performed.", new DoubleValue(1)));


68  }


69 


70  public override IDeepCloneable Clone(Cloner cloner) {


71  return new PolynomialAllPositionManipulator(this, cloner);


72  }


73 


74  /// <summary>


75  /// Performs the polynomial mutation on a single position in the real vector.


76  /// </summary>


77  /// <param name="random">The random number generator to use.</param>


78  /// <param name="vector">The vector that should be manipulated.</param>


79  /// <param name="contiguity">A parameter describing the shape of the probability density function which influences the strength of the manipulation.</param>


80  /// <param name="maxManipulation">The maximum strength of the manipulation.</param>


81  public static void Apply(IRandom random, RealVector vector, DoubleValue contiguity, DoubleValue maxManipulation) {


82  if (contiguity.Value < 0) throw new ArgumentException("PolynomialAllPositionManipulator: Contiguity value is smaller than 0", "contiguity");


83  double u, delta = 0;


84 


85  for (int index = 0; index < vector.Length; index++) {


86  u = random.NextDouble();


87  if (u < 0.5) {


88  delta = Math.Pow(2 * u, 1.0 / (contiguity.Value + 1))  1.0;


89  } else if (u >= 0.5) {


90  delta = 1.0  Math.Pow(2.0  2.0 * u, 1.0 / (contiguity.Value + 1));


91  }


92 


93  vector[index] += delta * maxManipulation.Value;


94  }


95  }


96 


97  /// <summary>


98  /// Checks the availability of the parameters and forwards the call to <see cref="Apply(IRandom, RealVector, DoubleValue, DoubleValue)"/>.


99  /// </summary>


100  /// <param name="random">The random number generator to use.</param>


101  /// <param name="realVector">The vector of real values to manipulate.</param>


102  protected override void Manipulate(IRandom random, RealVector realVector) {


103  if (ContiguityParameter.ActualValue == null) throw new InvalidOperationException("PolynomialAllPositionManipulator: Parameter " + ContiguityParameter.ActualName + " could not be found.");


104  if (MaximumManipulationParameter.ActualValue == null) throw new InvalidOperationException("PolynomialAllPositionManipulator: Parameter " + MaximumManipulationParameter.ActualName + " could not be found.");


105  Apply(random, realVector, ContiguityParameter.ActualValue, MaximumManipulationParameter.ActualValue);


106  }


107  }


108  }

