source: branches/ScatterSearch (trunk integration)/HeuristicLab.Problems.TravelingSalesman/3.3/SimilarityCalculators/TSPSimilarityCalculator.cs @ 8303

Last change on this file since 8303 was 8303, checked in by jkarder, 7 years ago

#1331: made similarity calculators storable and cloneable

File size: 2.8 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2012 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
22using System;
23using HeuristicLab.Common;
24using HeuristicLab.Core;
25using HeuristicLab.Encodings.PermutationEncoding;
26using HeuristicLab.Optimization.Operators;
27
28namespace 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}
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