source: branches/GeneralizedQAP/HeuristicLab.Problems.GeneralizedQuadraticAssignment.Algorithms/3.3/LocalSearch/IteratedLS.cs @ 15564

Last change on this file since 15564 was 15564, checked in by abeham, 2 years ago

#1614:

  • Fixed some bugs
  • Added OSGA
  • Updated ES (added recombination)
  • Reusing operators among algorihtms (RelocateEquipmentManipluator)
  • Rewrote DiscreteLocationCrossover
File size: 6.8 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2017 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.Threading;
24using HeuristicLab.Common;
25using HeuristicLab.Core;
26using HeuristicLab.Data;
27using HeuristicLab.Optimization;
28using HeuristicLab.Parameters;
29using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
30
31namespace HeuristicLab.Problems.GeneralizedQuadraticAssignment.Algorithms.LocalSearch {
32  [Item("Iterated Local Search (GQAP)", "Iterated local search for the GQAP.")]
33  [Creatable(CreatableAttribute.Categories.SingleSolutionAlgorithms)]
34  [StorableClass]
35  public sealed class IteratedLS : StochasticAlgorithm<LocalSearchContext> {
36
37    public override bool SupportsPause {
38      get { return true; }
39    }
40
41    public override Type ProblemType {
42      get { return typeof(GQAP); }
43    }
44
45    public new GQAP Problem {
46      get { return (GQAP)base.Problem; }
47      set { base.Problem = value; }
48    }
49
50    [Storable]
51    private IFixedValueParameter<PercentValue> perturbationStrengthParameter;
52    public IFixedValueParameter<PercentValue> PerturbationStrengthParameter {
53      get { return perturbationStrengthParameter; }
54    }
55
56    public double PerturbationStrength {
57      get { return perturbationStrengthParameter.Value.Value; }
58      set { perturbationStrengthParameter.Value.Value = value; }
59    }
60
61    [StorableConstructor]
62    private IteratedLS(bool deserializing) : base(deserializing) { }
63    private IteratedLS(IteratedLS original, Cloner cloner)
64      : base(original, cloner) {
65    }
66    public IteratedLS() {
67      Parameters.Add(perturbationStrengthParameter = new FixedValueParameter<PercentValue>("PerturbationStrength", "The expected length of the random walk relative to the size of the solution vector.", new PercentValue(0.5)));
68
69      Problem = new GQAP();
70    }
71   
72    public override IDeepCloneable Clone(Cloner cloner) {
73      return new IteratedLS(this, cloner);
74    }
75
76    protected override void Initialize(CancellationToken token) {
77      base.Initialize(token);
78
79      Context.Problem = Problem;
80      Context.BestQuality = double.NaN;
81      Context.BestSolution = null;
82
83      var assign = GreedyRandomizedSolutionCreator.CreateSolution(Context.Random, Problem.ProblemInstance, 10, true, token);
84      var eval = Problem.ProblemInstance.Evaluate(assign);
85      var fit = Problem.ProblemInstance.ToSingleObjective(eval);
86      Context.EvaluatedSolutions++;
87
88      var candidate = new GQAPSolution(assign, eval);
89      var lsevaluations = 0;
90      OneOptLocalSearch.Apply(Context.Random, candidate, Problem.ProblemInstance, out lsevaluations);
91      Context.EvaluatedSolutions += lsevaluations;
92
93      Context.ReplaceIncumbent(Context.ToScope(candidate, fit));
94      Context.BestQuality = fit;
95      Context.BestSolution = (GQAPSolution)candidate.Clone();
96
97      Results.Add(new Result("Iterations", new IntValue(Context.Iterations)));
98      Results.Add(new Result("EvaluatedSolutions", new IntValue(Context.EvaluatedSolutions)));
99      Results.Add(new Result("BestQuality", new DoubleValue(Context.BestQuality)));
100      Results.Add(new Result("BestSolution", Context.BestSolution));
101
102      Context.RunOperator(Analyzer, Context.Scope, token);
103    }
104
105    protected override void Run(CancellationToken cancellationToken) {
106      var lastUpdate = ExecutionTime;
107
108      while (!StoppingCriterion()) {
109        var lsevaluations = 0;
110        var candidate = (GQAPSolution)Context.Incumbent.Solution.Clone();
111        RelocateEquipmentManipluator.Apply(Context.Random, candidate.Assignment, Problem.ProblemInstance.Capacities.Length, 1.0 / (PerturbationStrength * candidate.Assignment.Length));
112        candidate.Evaluation = Problem.ProblemInstance.Evaluate(candidate.Assignment);
113        Context.EvaluatedSolutions++;
114        OneOptLocalSearch.Apply(Context.Random, candidate, Problem.ProblemInstance, out lsevaluations);
115        Context.EvaluatedSolutions += lsevaluations;
116
117        var candidateFit = Problem.ProblemInstance.ToSingleObjective(candidate.Evaluation);
118        if (candidateFit < Context.Incumbent.Fitness) {
119          Context.ReplaceIncumbent(Context.ToScope(candidate, candidateFit));
120          Context.BestQuality = candidateFit;
121          Context.BestSolution = (GQAPSolution)candidate.Clone();
122        }
123
124        IResult result;
125        if (ExecutionTime - lastUpdate > TimeSpan.FromSeconds(1)) {
126          if (Results.TryGetValue("Iterations", out result))
127            ((IntValue)result.Value).Value = Context.Iterations;
128          else Results.Add(new Result("Iterations", new IntValue(Context.Iterations)));
129          if (Results.TryGetValue("EvaluatedSolutions", out result))
130            ((IntValue)result.Value).Value = Context.EvaluatedSolutions;
131          else Results.Add(new Result("EvaluatedSolutions", new IntValue(Context.EvaluatedSolutions)));
132          lastUpdate = ExecutionTime;
133        }
134        if (Results.TryGetValue("BestQuality", out result))
135          ((DoubleValue)result.Value).Value = Context.BestQuality;
136        else Results.Add(new Result("BestQuality", new DoubleValue(Context.BestQuality)));
137        if (Results.TryGetValue("BestSolution", out result))
138          result.Value = Context.BestSolution;
139        else Results.Add(new Result("BestSolution", Context.BestSolution));
140
141        try {
142          Context.RunOperator(Analyzer, Context.Scope, cancellationToken);
143        } catch (OperationCanceledException) { }
144
145        Context.Iterations++;
146        if (cancellationToken.IsCancellationRequested) break;
147      }
148      IResult result2;
149      if (Results.TryGetValue("Iterations", out result2))
150        ((IntValue)result2.Value).Value = Context.Iterations;
151      else Results.Add(new Result("Iterations", new IntValue(Context.Iterations)));
152      if (Results.TryGetValue("EvaluatedSolutions", out result2))
153        ((IntValue)result2.Value).Value = Context.EvaluatedSolutions;
154      else Results.Add(new Result("EvaluatedSolutions", new IntValue(Context.EvaluatedSolutions)));
155    }
156  }
157}
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