1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022017 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 System;


23  using System.Threading;


24  using HeuristicLab.Common;


25  using HeuristicLab.Core;


26  using HeuristicLab.Data;


27  using HeuristicLab.Encodings.IntegerVectorEncoding;


28  using HeuristicLab.Optimization;


29  using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;


30 


31  namespace HeuristicLab.Problems.GeneralizedQuadraticAssignment.Algorithms.LocalSearch {


32  [Item("Multistart Local Search (GQAP)", "Multistart local search for the GQAP.")]


33  [Creatable(CreatableAttribute.Categories.SingleSolutionAlgorithms)]


34  [StorableClass]


35  public sealed class MultistartLS : StochasticAlgorithm<LocalSearchContext, IntegerVectorEncoding> {


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  [StorableConstructor]


51  private MultistartLS(bool deserializing) : base(deserializing) { }


52  private MultistartLS(MultistartLS original, Cloner cloner)


53  : base(original, cloner) {


54  }


55  public MultistartLS() {


56 


57  Problem = new GQAP();


58  }


59 


60  public override IDeepCloneable Clone(Cloner cloner) {


61  return new MultistartLS(this, cloner);


62  }


63 


64  protected override void Initialize(CancellationToken token) {


65  base.Initialize(token);


66 


67  Context.Problem = Problem;


68  Context.BestQuality = double.NaN;


69  Context.BestSolution = null;


70  }


71 


72  protected override void Run(CancellationToken cancellationToken) {


73  var lastUpdate = ExecutionTime;


74 


75  while (!StoppingCriterion()) {


76  var lsevaluations = 0;


77  var assign = new IntegerVector(Problem.ProblemInstance.Demands.Length, Context.Random, 0, Problem.ProblemInstance.Capacities.Length);


78  var eval = Problem.ProblemInstance.Evaluate(assign);


79  Context.EvaluatedSolutions++;


80 


81  var candidate = new GQAPSolution(assign, eval);


82  OneOptLocalSearch.Apply(Context.Random, candidate, Problem.ProblemInstance, out lsevaluations);


83  Context.EvaluatedSolutions += lsevaluations;


84 


85  var candidateFit = Problem.ProblemInstance.ToSingleObjective(candidate.Evaluation);


86  if (Context.Incumbent == null  candidateFit < Context.Incumbent.Fitness) {


87  Context.ReplaceIncumbent(Context.ToScope(candidate, candidateFit));


88  Context.BestQuality = candidateFit;


89  Context.BestSolution = (GQAPSolution)candidate.Clone();


90  }


91 


92  IResult result;


93  if (ExecutionTime  lastUpdate > TimeSpan.FromSeconds(1)) {


94  if (Results.TryGetValue("Iterations", out result))


95  ((IntValue)result.Value).Value = Context.Iterations;


96  else Results.Add(new Result("Iterations", new IntValue(Context.Iterations)));


97  if (Results.TryGetValue("EvaluatedSolutions", out result))


98  ((IntValue)result.Value).Value = Context.EvaluatedSolutions;


99  else Results.Add(new Result("EvaluatedSolutions", new IntValue(Context.EvaluatedSolutions)));


100  lastUpdate = ExecutionTime;


101  }


102  if (Results.TryGetValue("BestQuality", out result))


103  ((DoubleValue)result.Value).Value = Context.BestQuality;


104  else Results.Add(new Result("BestQuality", new DoubleValue(Context.BestQuality)));


105  if (Results.TryGetValue("BestSolution", out result))


106  result.Value = Context.BestSolution;


107  else Results.Add(new Result("BestSolution", Context.BestSolution));


108 


109  try {


110  Context.RunOperator(Analyzer, Context.Scope, cancellationToken);


111  } catch (OperationCanceledException) { }


112 


113  Context.Iterations++;


114  if (cancellationToken.IsCancellationRequested) break;


115  }


116 


117  IResult result2;


118  if (Results.TryGetValue("Iterations", out result2))


119  ((IntValue)result2.Value).Value = Context.Iterations;


120  else Results.Add(new Result("Iterations", new IntValue(Context.Iterations)));


121  if (Results.TryGetValue("EvaluatedSolutions", out result2))


122  ((IntValue)result2.Value).Value = Context.EvaluatedSolutions;


123  else Results.Add(new Result("EvaluatedSolutions", new IntValue(Context.EvaluatedSolutions)));


124  }


125  }


126  }

