source: branches/2839_HiveProjectManagement/HeuristicLab.Encodings.PermutationEncoding/3.3/Moves/ThreeOpt/StochasticSingleInsertionMoveGenerator.cs @ 16057

Last change on this file since 16057 was 16057, checked in by jkarder, 15 months ago

#2839:

File size: 4.5 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2018 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 System.Collections.Generic;
24using HeuristicLab.Common;
25using HeuristicLab.Core;
26using HeuristicLab.Data;
27using HeuristicLab.Optimization;
28using HeuristicLab.Parameters;
29using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
30
31namespace HeuristicLab.Encodings.PermutationEncoding {
32  [Item("StochasticInsertionMultiMoveGenerator", "Generates all possible insertion moves (3-opt) from a few numbers in a given permutation.")]
33  [StorableClass]
34  public class StochasticInsertionMultiMoveGenerator : TranslocationMoveGenerator, IMultiMoveGenerator, IStochasticOperator {
35    public ILookupParameter<IRandom> RandomParameter {
36      get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
37    }
38    public IValueLookupParameter<IntValue> SampleSizeParameter {
39      get { return (IValueLookupParameter<IntValue>)Parameters["SampleSize"]; }
40    }
41
42    public IntValue SampleSize {
43      get { return SampleSizeParameter.Value; }
44      set { SampleSizeParameter.Value = value; }
45    }
46
47    [StorableConstructor]
48    protected StochasticInsertionMultiMoveGenerator(bool deserializing) : base(deserializing) { }
49    protected StochasticInsertionMultiMoveGenerator(StochasticInsertionMultiMoveGenerator original, Cloner cloner) : base(original, cloner) { }
50    public StochasticInsertionMultiMoveGenerator() : base() {
51      Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator to use."));
52      Parameters.Add(new ValueLookupParameter<IntValue>("SampleSize", "The number of moves to generate."));
53    }
54
55    public override IDeepCloneable Clone(Cloner cloner) {
56      return new StochasticInsertionMultiMoveGenerator(this, cloner);
57    }
58
59    public static TranslocationMove[] Apply(Permutation permutation, IRandom random, int sampleSize) {
60      int length = permutation.Length;
61      if (length == 1) throw new ArgumentException("ExhaustiveSingleInsertionMoveGenerator: There cannot be an insertion move given a permutation of length 1.", "permutation");
62      TranslocationMove[] moves = new TranslocationMove[sampleSize];
63      int count = 0;
64      HashSet<int> usedIndices = new HashSet<int>();
65      while (count < sampleSize) {
66
67        int index = random.Next(length);
68
69        if (usedIndices.Count != length)
70          while (usedIndices.Contains(index))
71            index = random.Next(length);
72        usedIndices.Add(index);
73
74        if (permutation.PermutationType == PermutationTypes.Absolute) {
75          for (int j = 1; j <= length - 1; j++) {
76            moves[count++] = new TranslocationMove(index, index, (index + j) % length);
77            if (count == sampleSize) break;
78          }
79        } else {
80          if (length > 2) {
81            for (int j = 1; j < length - 1; j++) {
82              int insertPoint = (index + j) % length;
83              if (index + j >= length) insertPoint++;
84              moves[count++] = new TranslocationMove(index, index, insertPoint);
85              if (count == sampleSize) break;
86            }
87          } else { // doesn't make sense, but just create a dummy move to not crash the algorithms
88            moves = new TranslocationMove[1];
89            moves[0] = new TranslocationMove(0, 0, 1);
90            count = sampleSize;
91          }
92        }
93      }
94      return moves;
95    }
96
97    protected override TranslocationMove[] GenerateMoves(Permutation permutation) {
98      IRandom random = RandomParameter.ActualValue;
99      if (random == null) throw new InvalidOperationException(Name + ": No random number generator found.");
100      return Apply(permutation, random, SampleSizeParameter.ActualValue.Value);
101    }
102  }
103}
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