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.Optimization;


26  using HeuristicLab.Parameters;


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


28 


29  namespace HeuristicLab.Encodings.PermutationEncoding {


30  [Item("StochasticInversionSingleMoveGenerator", "Randomly samples a single from all possible inversion moves (2opt) from a given permutation.")]


31  [StorableClass]


32  public class StochasticInversionSingleMoveGenerator : InversionMoveGenerator, IStochasticOperator, ISingleMoveGenerator {


33  public ILookupParameter<IRandom> RandomParameter {


34  get { return (ILookupParameter<IRandom>)Parameters["Random"]; }


35  }


36 


37  [StorableConstructor]


38  protected StochasticInversionSingleMoveGenerator(bool deserializing) : base(deserializing) { }


39  protected StochasticInversionSingleMoveGenerator(StochasticInversionSingleMoveGenerator original, Cloner cloner) : base(original, cloner) { }


40  public StochasticInversionSingleMoveGenerator()


41  : base() {


42  Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator."));


43  }


44 


45  public override IDeepCloneable Clone(Cloner cloner) {


46  return new StochasticInversionSingleMoveGenerator(this, cloner);


47  }


48 


49  public static InversionMove Apply(Permutation permutation, IRandom random) {


50  int length = permutation.Length;


51  if (length == 1) throw new ArgumentException("StochasticInversionSingleMoveGenerator: There cannot be an inversion move given a permutation of length 1.", "permutation");


52  int index1 = random.Next(length  1);


53  int index2 = random.Next(index1 + 1, length);


54  if (permutation.PermutationType == PermutationTypes.RelativeUndirected) {


55  if (length > 3) {


56  while (index2  index1 >= length  2)


57  index2 = random.Next(index1 + 1, length);


58  }


59  }


60  return new InversionMove(index1, index2);


61  }


62 


63  protected override InversionMove[] GenerateMoves(Permutation permutation) {


64  IRandom random = RandomParameter.ActualValue;


65  return new InversionMove[] { Apply(permutation, random) };


66  }


67  }


68  }

