1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022012 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.Encodings.PermutationEncoding;


26  using HeuristicLab.Optimization.Operators;


27 


28  namespace HeuristicLab.Problems.TravelingSalesman {


29  /// <summary>


30  /// An operator that performs similarity calculation between two traveling salesman solutions.


31  /// </summary>


32  [Item("TSPSimilarityCalculator", "An operator that performs similarity calculation between two traveling salesman solutions.")]


33  public sealed class TSPSimilarityCalculator : SimilarityCalculator {


34  private TSPSimilarityCalculator(bool deserializing) : base(deserializing) { }


35  private TSPSimilarityCalculator(TSPSimilarityCalculator original, Cloner cloner) : base(original, cloner) { }


36  public TSPSimilarityCalculator() : base() { }


37 


38  public override IDeepCloneable Clone(Cloner cloner) {


39  return new TSPSimilarityCalculator(this, cloner);


40  }


41 


42  public static double CalculateSimilarity(Permutation left, Permutation right) {


43  if (left == null  right == null)


44  throw new ArgumentException("Cannot calculate similarity because one of the provided solutions or both are null.");


45 


46  int[,] edges = new int[right.Length, 2];


47  for (int i = 0; i < right.Length; i++) {


48  edges[right[i], 0] = right[(i + 1) % right.Length];


49  edges[right[i], 1] = right[(i  1 + right.Length) % right.Length];


50  }


51 


52  double similarity = 0.0;


53  for (int i = 0; i < left.Length; i++) {


54  int targetCity = left[(i + 1) % left.Length];


55  if (targetCity == edges[left[i], 0]  targetCity == edges[left[i], 1])


56  similarity++;


57  }


58 


59  return similarity / left.Length;


60  }


61 


62  protected override double CalculateSimilarity(IScope left, IScope right) {


63  Permutation sol1 = left.Variables[Target].Value as Permutation;


64  Permutation sol2 = right.Variables[Target].Value as Permutation;


65 


66  return CalculateSimilarity(sol1, sol2);


67  }


68  }


69  }

