1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022010 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.Core;


23  using HeuristicLab.Encodings.PermutationEncoding;


24  using HeuristicLab.Parameters;


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


26  using HeuristicLab.Data;


27  using HeuristicLab.Optimization;


28  using HeuristicLab.Problems.VehicleRouting.Encodings.General;


29  using HeuristicLab.Problems.VehicleRouting.Interfaces;


30  using HeuristicLab.Common;


31 


32  namespace HeuristicLab.Problems.VehicleRouting.Encodings.Potvin {


33  [Item("PotvinManipulator", "A VRP manipulation operation.")]


34  [StorableClass]


35  public abstract class PotvinManipulator : VRPManipulator, IStochasticOperator, IPotvinOperator {


36  public ILookupParameter<IRandom> RandomParameter {


37  get { return (LookupParameter<IRandom>)Parameters["Random"]; }


38  }


39 


40  public IValueParameter<BoolValue> AllowInfeasibleSolutions {


41  get { return (IValueParameter<BoolValue>)Parameters["AllowInfeasibleSolutions"]; }


42  }


43 


44  [StorableConstructor]


45  protected PotvinManipulator(bool deserializing) : base(deserializing) { }


46 


47  public PotvinManipulator() {


48  Parameters.Add(new LookupParameter<IRandom>("Random", "The pseudo random number generator which should be used for stochastic manipulation operators."));


49  Parameters.Add(new ValueParameter<BoolValue>("AllowInfeasibleSolutions", "Indicates if infeasible solutions should be allowed.", new BoolValue(false)));


50  }


51 


52  protected PotvinManipulator(PotvinManipulator original, Cloner cloner)


53  : base(original, cloner) {


54  }


55 


56  protected abstract void Manipulate(IRandom random, PotvinEncoding individual);


57 


58  protected int SelectRandomTourBiasedByLength(IRandom random, PotvinEncoding individual) {


59  int tourIndex = 1;


60 


61  double sum = 0.0;


62  double[] probabilities = new double[individual.Tours.Count];


63  for (int i = 0; i < individual.Tours.Count; i++) {


64  probabilities[i] = 1.0 / ((double)individual.Tours[i].Stops.Count / (double)ProblemInstance.Cities.Value);


65  sum += probabilities[i];


66  }


67 


68  for (int i = 0; i < probabilities.Length; i++)


69  probabilities[i] = probabilities[i] / sum;


70 


71  double rand = random.NextDouble();


72  double cumulatedProbabilities = 0.0;


73  int index = 0;


74  while (tourIndex == 1 && index < probabilities.Length) {


75  if (cumulatedProbabilities <= rand && rand <= cumulatedProbabilities + probabilities[index])


76  tourIndex = index;


77 


78  cumulatedProbabilities += probabilities[index];


79  index++;


80  }


81 


82  return tourIndex;


83  }


84 


85  protected bool FindInsertionPlace(PotvinEncoding individual, int city, int routeToAvoid, bool allowInfeasible, out int route, out int place) {


86  return individual.FindInsertionPlace(


87  city, routeToAvoid, allowInfeasible, out route, out place);


88  }


89 


90  public override IOperation Apply() {


91  IVRPEncoding solution = VRPToursParameter.ActualValue;


92  if (!(solution is PotvinEncoding)) {


93  VRPToursParameter.ActualValue = PotvinEncoding.ConvertFrom(solution, ProblemInstance);


94  }


95 


96  Manipulate(RandomParameter.ActualValue, VRPToursParameter.ActualValue as PotvinEncoding);


97 


98  return base.Apply();


99  }


100  }


101  }

