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source: branches/PTSP/HeuristicLab.Problems.PTSP/3.3/MoveGenerators/Stochastic25SingleMoveGenerator.cs @ 12272

Last change on this file since 12272 was 12272, checked in by apolidur, 9 years ago

#2221: Adding 2.5-opt-EEs operators to PTSP

File size: 3.1 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2015 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.Optimization;
26using HeuristicLab.Parameters;
27using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
28using HeuristicLab.Operators;
29using HeuristicLab.Encodings.PermutationEncoding;
30
31
32namespace HeuristicLab.Problems.PTSP {
33  [Item("Stochastic25SingleMoveGenerator", "Randomly samples a single from all possible inversion and shift moves (2.5-opt) from a given permutation.")]
34  [StorableClass]
35  class Stochastic25SingleMoveGenerator : TwoPointFiveMoveGenerator, IStochasticOperator, ISingleMoveGenerator {
36    public ILookupParameter<IRandom> RandomParameter {
37      get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
38    }
39
40    [StorableConstructor]
41    protected Stochastic25SingleMoveGenerator(bool deserializing) : base(deserializing) { }
42    protected Stochastic25SingleMoveGenerator(Stochastic25SingleMoveGenerator original, Cloner cloner) : base(original, cloner) { }
43    public Stochastic25SingleMoveGenerator()
44      : base() {
45      Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator."));
46    }
47
48    public override IDeepCloneable Clone(Cloner cloner) {
49      return new Stochastic25SingleMoveGenerator(this, cloner);
50    }
51
52    public static TwoPointFiveMove Apply(Permutation permutation, IRandom random) {
53      int length = permutation.Length;
54      if (length == 1) throw new ArgumentException("Stochastic25SingleMoveGenerator: There cannot be an inversion move given a permutation of length 1.", "permutation");
55      int index1 = random.Next(length - 1);
56      int index2 = random.Next(index1 + 1, length);
57      if (permutation.PermutationType == PermutationTypes.RelativeUndirected) {
58        if (length > 3) {
59          while (index2 - index1 >= length - 2)
60            index2 = random.Next(index1 + 1, length);
61        }
62      }
63      bool isInvert = random.NextDouble() > 0.5;
64      return new TwoPointFiveMove(index1, index2, isInvert);
65     
66    }
67
68    protected override TwoPointFiveMove[] GenerateMoves(Permutation permutation) {
69      IRandom random = RandomParameter.ActualValue;
70      return new TwoPointFiveMove[] { Apply(permutation, random) };
71    }
72  }
73}
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