1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022015 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.BinaryVectorEncoding;


26  using HeuristicLab.Optimization.Operators;


27 


28  namespace HeuristicLab.Problems.Knapsack {


29  /// <summary>


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


31  /// </summary>


32  /// <remarks>


33  /// The operator calculates the similarity based on the number of elements the two solutions have in common.


34  /// </remarks>


35  [Item("KnapsackSimilarityCalculator", "An operator that performs similarity calculation between two knapsack solutions. The operator calculates the similarity based on the number of elements the two solutions have in common.")]


36  public sealed class KnapsackSimilarityCalculator : SingleObjectiveSolutionSimilarityCalculator {


37  protected override bool IsCommutative { get { return true; } }


38 


39  private KnapsackSimilarityCalculator(bool deserializing) : base(deserializing) { }


40  private KnapsackSimilarityCalculator(KnapsackSimilarityCalculator original, Cloner cloner) : base(original, cloner) { }


41  public KnapsackSimilarityCalculator() : base() { }


42 


43  public override IDeepCloneable Clone(Cloner cloner) {


44  return new KnapsackSimilarityCalculator(this, cloner);


45  }


46 


47  public static double CalculateSimilarity(BinaryVector left, BinaryVector right) {


48  if (left == null  right == null)


49  throw new ArgumentException("Cannot calculate similarity because one or both of the provided scopes is null.");


50  if (left.Length != right.Length)


51  throw new ArgumentException("Cannot calculate similarity because the provided solutions have different lengths.");


52  if (left == right) return 1.0;


53 


54  double similarity = 0.0;


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


56  if (left[i] == right[i]) similarity++;


57  return similarity / left.Length;


58  }


59 


60  public override double CalculateSolutionSimilarity(IScope leftSolution, IScope rightSolution) {


61  var sol1 = leftSolution.Variables[SolutionVariableName].Value as BinaryVector;


62  var sol2 = rightSolution.Variables[SolutionVariableName].Value as BinaryVector;


63 


64  return CalculateSimilarity(sol1, sol2);


65  }


66  }


67  }

