1 | #region License Information
|
---|
2 | /* HeuristicLab
|
---|
3 | * Copyright (C) 2002-2010 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 HeuristicLab.Core;
|
---|
23 | using HeuristicLab.Encodings.PermutationEncoding;
|
---|
24 | using HeuristicLab.Parameters;
|
---|
25 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
|
---|
26 | using HeuristicLab.Data;
|
---|
27 |
|
---|
28 | namespace HeuristicLab.Problems.VehicleRouting.Encodings.Potvin {
|
---|
29 | [Item("PotvinSBXCrossover", "The SBX crossover for the Potvin VRP representations. It is implemented as described in Potvin, J.-Y. and Bengio, S. (1996). The Vehicle Routing Problem with Time Windows - Part II: Genetic Search. INFORMS Journal of Computing, 8:165–172.")]
|
---|
30 | [StorableClass]
|
---|
31 | public sealed class PotvinSBXCrossover : PotvinCrossover {
|
---|
32 | private Tour FindRoute(PotvinEncoding solution, int city) {
|
---|
33 | Tour found = null;
|
---|
34 |
|
---|
35 | foreach (Tour tour in solution.Tours) {
|
---|
36 | if (tour.Cities.Contains(city)) {
|
---|
37 | found = tour;
|
---|
38 | break;
|
---|
39 | }
|
---|
40 | }
|
---|
41 |
|
---|
42 | return found;
|
---|
43 | }
|
---|
44 |
|
---|
45 | protected override PotvinEncoding Crossover(IRandom random, PotvinEncoding parent1, PotvinEncoding parent2) {
|
---|
46 | PotvinEncoding child = parent1.Clone() as PotvinEncoding;
|
---|
47 | Tour newTour = new Tour();
|
---|
48 |
|
---|
49 | int breakPoint1 = random.Next(1, Cities + 1);
|
---|
50 | Tour tour1 = FindRoute(child, breakPoint1);
|
---|
51 | breakPoint1 = tour1.Cities.IndexOf(breakPoint1);
|
---|
52 |
|
---|
53 | for (int i = 0; i < breakPoint1; i++)
|
---|
54 | newTour.Cities.Add(tour1.Cities[i]);
|
---|
55 |
|
---|
56 | int breakPoint2 = random.Next(1, Cities + 1);
|
---|
57 | Tour tour2 = FindRoute(parent2, breakPoint2);
|
---|
58 | breakPoint2 = tour2.Cities.IndexOf(breakPoint2);
|
---|
59 |
|
---|
60 | for (int i = breakPoint2; i < tour2.Cities.Count; i++)
|
---|
61 | newTour.Cities.Add(tour2.Cities[i]);
|
---|
62 |
|
---|
63 | child.Tours.Remove(tour1);
|
---|
64 | child.Tours.Add(newTour);
|
---|
65 |
|
---|
66 | foreach (int city in tour1.Cities)
|
---|
67 | if (FindRoute(child, city) == null && !child.Unrouted.Contains(city))
|
---|
68 | child.Unrouted.Add(city);
|
---|
69 |
|
---|
70 | foreach (int city in tour2.Cities)
|
---|
71 | if (FindRoute(child, city) == null && !child.Unrouted.Contains(city))
|
---|
72 | child.Unrouted.Add(city);
|
---|
73 |
|
---|
74 | if (Repair(random, child, newTour))
|
---|
75 | return child;
|
---|
76 | else {
|
---|
77 | if(random.NextDouble() < 0.5)
|
---|
78 | return parent1.Clone() as PotvinEncoding;
|
---|
79 | else
|
---|
80 | return parent2.Clone() as PotvinEncoding;
|
---|
81 | }
|
---|
82 | }
|
---|
83 | }
|
---|
84 | }
|
---|