1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022019 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.Optimization;


27  using HeuristicLab.Parameters;


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


29 


30  namespace HeuristicLab.Encodings.RealVectorEncoding {


31  /// <summary>


32  /// The solution is manipulated with diminishing strength over time. In addition the mutated values are not sampled over the entire domain, but additive.<br/>


33  /// Initially, the space will be searched uniformly and very locally at later stages. This increases the probability of generating the new numbers closer to the current value.


34  /// </summary>


35  /// <remarks>


36  /// It is implemented as described in Michalewicz, Z. 1999. Genetic Algorithms + Data Structures = Evolution Programs. Third, Revised and Extended Edition, SpringVerlag Berlin Heidelberg.


37  /// </remarks>


38  [Item("MichalewiczNonUniformAllPositionsManipulator", "It is implemented as described in Michalewicz, Z. 1999. Genetic Algorithms + Data Structures = Evolution Programs. Third, Revised and Extended Edition, SpringVerlag Berlin Heidelberg.")]


39  [StorableClass]


40  public class MichalewiczNonUniformAllPositionsManipulator : RealVectorManipulator, IIterationBasedOperator {


41  /// <summary>


42  /// The current iteration.


43  /// </summary>


44  public ILookupParameter<IntValue> IterationsParameter {


45  get { return (ILookupParameter<IntValue>)Parameters["Iterations"]; }


46  }


47  /// <summary>


48  /// The maximum iteration.


49  /// </summary>


50  public IValueLookupParameter<IntValue> MaximumIterationsParameter {


51  get { return (IValueLookupParameter<IntValue>)Parameters["MaximumIterations"]; }


52  }


53  /// <summary>


54  /// The parameter describing how much the mutation should depend on the progress towards the maximum iteration.


55  /// </summary>


56  public ValueLookupParameter<DoubleValue> IterationDependencyParameter {


57  get { return (ValueLookupParameter<DoubleValue>)Parameters["IterationDependency"]; }


58  }


59 


60  [StorableConstructor]


61  protected MichalewiczNonUniformAllPositionsManipulator(bool deserializing) : base(deserializing) { }


62  protected MichalewiczNonUniformAllPositionsManipulator(MichalewiczNonUniformAllPositionsManipulator original, Cloner cloner) : base(original, cloner) { }


63  /// <summary>


64  /// Initializes a new instance of <see cref="MichalewiczNonUniformAllPositionsManipulator"/> with three


65  /// parameters (<c>Iterations</c>, <c>MaximumIterations</c> and <c>IterationDependency</c>).


66  /// </summary>


67  public MichalewiczNonUniformAllPositionsManipulator()


68  : base() {


69  Parameters.Add(new LookupParameter<IntValue>("Iterations", "Current iteration of the algorithm"));


70  Parameters.Add(new ValueLookupParameter<IntValue>("MaximumIterations", "Maximum number of iterations"));


71  Parameters.Add(new ValueLookupParameter<DoubleValue>("IterationDependency", "Specifies the degree of dependency on the number of iterations. A value of 0 means no dependency and the higher the value the stronger the progress towards maximum iterations will be taken into account by sampling closer around the current position. Value must be >= 0.", new DoubleValue(5)));


72  }


73 


74  public override IDeepCloneable Clone(Cloner cloner) {


75  return new MichalewiczNonUniformAllPositionsManipulator(this, cloner);


76  }


77 


78  /// <summary>


79  /// Performs a non uniformly distributed all positions manipulation on the given


80  /// real <paramref name="vector"/>. The probability of stronger mutations reduces the more <see cref="currentIteration"/> approaches <see cref="maximumIterations"/>.


81  /// </summary>


82  /// <exception cref="ArgumentException">Thrown when <paramref name="currentIteration"/> is greater than <paramref name="maximumIterations"/>.</exception>


83  /// <param name="random">The random number generator.</param>


84  /// <param name="vector">The real vector to manipulate.</param>


85  /// <param name="bounds">The lower and upper bound (1st and 2nd column) of the positions in the vector. If there are less rows than dimensions, the rows are cycled.</param>


86  /// <param name="currentIteration">The current iteration of the algorithm.</param>


87  /// <param name="maximumIterations">Maximum number of iterations.</param>


88  /// <param name="iterationDependency">Specifies the degree of dependency on the number of iterations. A value of 0 means no dependency and the higher the value the stronger the progress towards maximum iterations will be taken into account by sampling closer around the current position. Value must be >= 0.</param>


89  /// <returns>The manipulated real vector.</returns>


90  public static void Apply(IRandom random, RealVector vector, DoubleMatrix bounds, IntValue currentIteration, IntValue maximumIterations, DoubleValue iterationDependency) {


91  if (currentIteration.Value > maximumIterations.Value) throw new ArgumentException("MichalewiczNonUniformAllPositionsManipulator: CurrentIteration must be smaller or equal than MaximumIterations", "currentIteration");


92  if (iterationDependency.Value < 0) throw new ArgumentException("MichalewiczNonUniformAllPositionsManipulator: iterationDependency must be >= 0.", "iterationDependency");


93  int length = vector.Length;


94 


95  double prob = Math.Pow(1  currentIteration.Value / maximumIterations.Value, iterationDependency.Value);


96 


97  for (int i = 0; i < length; i++) {


98  double min = bounds[i % bounds.Rows, 0];


99  double max = bounds[i % bounds.Rows, 1];


100  if (random.NextDouble() < 0.5) {


101  vector[i] = vector[i] + (max  vector[i]) * (1  Math.Pow(random.NextDouble(), prob));


102  } else {


103  vector[i] = vector[i]  (vector[i]  min) * (1  Math.Pow(random.NextDouble(), prob));


104  }


105  }


106  }


107 


108  /// <summary>


109  /// Checks if all parameters are available and forwards the call to <see cref="Apply(IRandom, RealVector, DoubleValue, DoubleValue, IntValue, IntValue, DoubleValue)"/>.


110  /// </summary>


111  /// <param name="random">The random number generator.</param>


112  /// <param name="realVector">The real vector that should be manipulated.</param>


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


114  if (BoundsParameter.ActualValue == null) throw new InvalidOperationException("MichalewiczNonUniformAllPositionManipulator: Parameter " + BoundsParameter.ActualName + " could not be found.");


115  if (IterationsParameter.ActualValue == null) throw new InvalidOperationException("MichalewiczNonUniformAllPositionManipulator: Parameter " + IterationsParameter.ActualName + " could not be found.");


116  if (MaximumIterationsParameter.ActualValue == null) throw new InvalidOperationException("MichalewiczNonUniformAllPositionManipulator: Parameter " + MaximumIterationsParameter.ActualName + " could not be found.");


117  if (IterationDependencyParameter.ActualValue == null) throw new InvalidOperationException("MichalewiczNonUniformAllPositionManipulator: Parameter " + IterationDependencyParameter.ActualName + " could not be found.");


118  Apply(random, realVector, BoundsParameter.ActualValue, IterationsParameter.ActualValue, MaximumIterationsParameter.ActualValue, IterationDependencyParameter.ActualValue);


119  }


120  }


121  }

