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source: branches/2839_HiveProjectManagement/HeuristicLab.Problems.PTSP/3.3/Moves/TwoOpt/PTSPEstimatedInversionMoveEvaluator.cs @ 15761

Last change on this file since 15761 was 14185, checked in by swagner, 8 years ago

#2526: Updated year of copyrights in license headers

File size: 4.5 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2016 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.Data;
26using HeuristicLab.Encodings.PermutationEncoding;
27using HeuristicLab.Parameters;
28using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
29
30namespace HeuristicLab.Problems.PTSP {
31  [Item("PTSP Estimated Inversion Move Evaluator", "Evaluates an inversion move (2-opt) over several realizations of tours by summing up the length of all added edges and subtracting the length of all deleted edges.")]
32  [StorableClass]
33  public class PTSPEstimatedInversionMoveEvaluator : EstimatedPTSPMoveEvaluator, IPermutationInversionMoveOperator {
34
35    public ILookupParameter<InversionMove> InversionMoveParameter {
36      get { return (ILookupParameter<InversionMove>)Parameters["InversionMove"]; }
37    }
38
39    [StorableConstructor]
40    protected PTSPEstimatedInversionMoveEvaluator(bool deserializing) : base(deserializing) { }
41    protected PTSPEstimatedInversionMoveEvaluator(PTSPEstimatedInversionMoveEvaluator original, Cloner cloner) : base(original, cloner) { }
42    public PTSPEstimatedInversionMoveEvaluator()
43      : base() {
44      Parameters.Add(new LookupParameter<InversionMove>("InversionMove", "The move to evaluate."));
45    }
46
47    public override IDeepCloneable Clone(Cloner cloner) {
48      return new PTSPEstimatedInversionMoveEvaluator(this, cloner);
49    }
50
51    public static double EvaluateMove(Permutation tour, InversionMove move, Func<int, int, double> distance, ItemList<BoolArray> realizations) {
52      double moveQuality = 0;
53      var edges = new int[4];
54      var indices = new int[4];
55      edges[0] = tour.GetCircular(move.Index1 - 1);
56      indices[0] = move.Index1 - 1;
57      if (indices[0] == -1) indices[0] = tour.Length - 1;
58      edges[1] = tour[move.Index1];
59      indices[1] = move.Index1;
60      edges[2] = tour[move.Index2];
61      indices[2] = move.Index2;
62      edges[3] = tour.GetCircular(move.Index2 + 1);
63      indices[3] = move.Index2 + 1;
64      if (indices[3] == tour.Length + 1) indices[3] = 0;
65      var aPosteriori = new int[4];
66      foreach (var realization in realizations) {
67        for (var i = 0; i < edges.Length; i++) {
68          if (realization[edges[i]]) {
69            aPosteriori[i] = edges[i];
70          } else {
71            var j = 1;
72            if (i % 2 == 0) {
73              // find nearest predecessor in realization if source edge
74              while (!realization[tour.GetCircular(indices[i] - j)]) {
75                j++;
76              }
77              aPosteriori[i] = tour.GetCircular(indices[i] - j);
78            } else {
79              // find nearest successor in realization if target edge
80              while (!realization[tour.GetCircular(indices[i] + j)]) {
81                j++;
82              }
83              aPosteriori[i] = tour.GetCircular(indices[i] + j);
84            }
85          }
86        }
87        // compute cost difference between the two a posteriori solutions
88        if (!(aPosteriori[0] == aPosteriori[2] && aPosteriori[1] == aPosteriori[3])) {
89          moveQuality = moveQuality + distance(aPosteriori[0], aPosteriori[2]) + distance(aPosteriori[1], aPosteriori[3])
90            - distance(aPosteriori[0], aPosteriori[1]) - distance(aPosteriori[2], aPosteriori[3]);
91        }
92        Array.Clear(aPosteriori, 0, aPosteriori.Length);
93      }
94      // return average of cost differences
95      return moveQuality / realizations.Count;
96    }
97
98    protected override double EvaluateMove(Permutation tour, Func<int, int, double> distance, ItemList<BoolArray> realizations) {
99      return EvaluateMove(tour, InversionMoveParameter.ActualValue, distance, realizations);
100    }
101  }
102}
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