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source: trunk/sources/HeuristicLab.Optimization/3.3/MoveHelper.cs @ 6042

Last change on this file since 6042 was 6042, checked in by abeham, 12 years ago

#1425

  • Changed LocalImprovementOperators
    • Changed interface (made Problem a property, added a property that denotes the type of the problem that it can be applied on, added some general parameters)
    • Added some parameters and wiring
    • Changed move discovery and parameterization and added a helper class to ease finding compatible move operators
    • Discovering only IMultiMoveOperators and IExhaustiveMoveOperators and putting the multi move ones first
    • Fixed bug in Apply method that could create an endless string of nested execution contexts
    • Removed all problem specific analyzers in the two local improvement operators and only left the BestAverageWorstQualityAnalyzer since it doesn't make any sense to perform diversity or allele analysis during local improvement in the most common case and those analyzers take a lot of time (one can always add them manually should he/she be interested). The analyzers in the VNS's Analyzer parameter are left untouched.
  • Removed shaking operator and interface from VNS plugin and added that to Optimization and Optimization.Operators
  • Changed some ValueParameters to ConstrainedValueParameters and added type discovery to fill them (using the ProblemType property to get compatible local improvement operators)
  • Added missing GPL license headers
  • Changed some ValueParameters to the new FixedValueParameters
  • Added an additional encoding specific ShakingOperator to each encoding and added that to each problem
    • reason is that only the problem/encoding can really decide if a shaking operator is meaningful or not
  • Fixed an unrelated bug in the BestAverageWorstQualityAnalyzer that I encountered (and made the fix backwards compatible)
    • Also added a snippet for creating the backwards compatible comment marker and region
  • Fixed the operator graph of the VNS main loop
    • The condition to continue only when the local search was not successful is not necessary and is not part of the VNS definition as far as I know it (only condition to break the inner loop is when k reaches k_max)
  • Changed the ShakingOperator to input current index and output the maximum number of neighborhoods instead of a boolean that indicates that the last index has been reached since the maximum number is a little more generally useful and equally powerful in modeling
    • Remodeled the VNS main loop to check for k < k_max in order to continue the inner loop
  • other changes that I forgot...

Still necessary

  • test, test, test
  • check for backwards compatible breakers
  • add a maximum evaluated solutions stop criterion
  • optionally: implement fast problem specific local search improvement operators that do not build on the whole generic overhead (e.g. a 2-opt TSP specific local search operator). The idea of VNS is really to converge to a local optimum which is difficult to achieve using the current rather limited termination options
File size: 3.0 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2011 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 System.Linq;
25using HeuristicLab.Core;
26
27namespace HeuristicLab.Optimization {
28  /// <summary>
29  /// This class provides some methods useful when dealing with moves, such as getting compatible move makers to a move generator.
30  /// Compatibility is generally ensured in that both the generator and the move maker implement the same specific interface which is derived from IMoveOperator
31  /// </summary>
32  public static class MoveHelper {
33
34    public static IEnumerable<IMoveMaker> GetCompatibleMoveMakers(IMoveGenerator generator, IEnumerable<IOperator> operators) {
35      return GetCompatibleOperators<IMoveMaker>(generator, operators);
36    }
37
38    public static IEnumerable<ISingleObjectiveMoveEvaluator> GetCompatibleSingleObjectiveMoveEvaluators(IMoveGenerator generator, IEnumerable<IOperator> operators) {
39      return GetCompatibleOperators<ISingleObjectiveMoveEvaluator>(generator, operators);
40    }
41
42    public static IEnumerable<ITabuChecker> GetCompatibleTabuChekers(IMoveGenerator generator, IEnumerable<IOperator> operators) {
43      return GetCompatibleOperators<ITabuChecker>(generator, operators);
44    }
45
46    public static IEnumerable<ITabuMaker> GetCompatibleTabuMakers(IMoveGenerator generator, IEnumerable<IOperator> operators) {
47      return GetCompatibleOperators<ITabuMaker>(generator, operators);
48    }
49
50    private static IEnumerable<T> GetCompatibleOperators<T>(IMoveGenerator generator, IEnumerable<IOperator> operators) where T : IOperator {
51      foreach (Type type in GetMostSpecificMoveOperatorTypes(generator)) {
52        foreach (T op in operators.Where(x => type.IsAssignableFrom(x.GetType())).OfType<T>())
53          yield return op;
54      }
55    }
56
57    private static List<Type> GetMostSpecificMoveOperatorTypes(IMoveGenerator generator) {
58      List<Type> moveTypes = generator.GetType().GetInterfaces().Where(x => typeof(IMoveOperator).IsAssignableFrom(x)).ToList();
59      foreach (Type type in moveTypes.ToList()) {
60        if (moveTypes.Any(t => t != type && type.IsAssignableFrom(t)))
61          moveTypes.Remove(type);
62      }
63      return moveTypes;
64    }
65  }
66}
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