1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022016 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.Collections.Generic;


23  using System.Linq;


24  using HeuristicLab.Common;


25  using HeuristicLab.Core;


26  using HeuristicLab.Data;


27  using HeuristicLab.Optimization;


28  using HeuristicLab.Parameters;


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


30 


31  namespace HeuristicLab.Algorithms.ParticleSwarmOptimization {


32  [Item("SPSO Random Topology Initializer", "Each particle informs k+1 other particles (including itself). The same particle (including itself) can be informed multiple times.")]


33  [StorableClass]


34  public sealed class SPSORandomTopologyInitializer : TopologyInitializer, IStochasticOperator {


35  #region Parameters


36  public ILookupParameter<IRandom> RandomParameter {


37  get { return (ILookupParameter<IRandom>)Parameters["Random"]; }


38  }


39  public IValueLookupParameter<IntValue> KParameter {


40  get { return (IValueLookupParameter<IntValue>)Parameters["K"]; }


41  }


42  #endregion


43 


44  #region Construction & Cloning


45  [StorableConstructor]


46  private SPSORandomTopologyInitializer(bool deserializing) : base(deserializing) { }


47  private SPSORandomTopologyInitializer(SPSORandomTopologyInitializer original, Cloner cloner) : base(original, cloner) { }


48  public SPSORandomTopologyInitializer() {


49  Parameters.Add(new LookupParameter<IRandom>("Random", "A random number generation."));


50  Parameters.Add(new ValueLookupParameter<IntValue>("K", "The number of informed particles (excluding itself).", new IntValue(3)));


51  }


52 


53  public override IDeepCloneable Clone(Cloner cloner) {


54  return new SPSORandomTopologyInitializer(this, cloner);


55  }


56  #endregion


57 


58  public override IOperation Apply() {


59  var random = RandomParameter.ActualValue;


60  var swarmSize = SwarmSizeParameter.ActualValue.Value;


61  var k = KParameter.ActualValue.Value;


62 


63  // SPSO: Each particle informs at most K+1 particles (at least itself and K others)


64  var particlesInform = Enumerable.Repeat(k + 1, swarmSize)


65  .Select((v, i) => new HashSet<int>(Enumerable.Range(0, v).Select(x => x == 0 ? i : random.Next(swarmSize)))).ToList();


66 


67  var neighbors = new ItemArray<IntArray>(swarmSize);


68  for (int i = 0; i < swarmSize; i++) {


69  // calculate the informants for each particle


70  var informants = particlesInform.Select((val, idx) => val.Contains(i) ? idx : 1).Where(x => x >= 0).ToArray();


71  neighbors[i] = new IntArray(informants);


72  }


73  NeighborsParameter.ActualValue = neighbors;


74  return base.Apply();


75  }


76  }


77  }

