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source: trunk/sources/HeuristicLab.Encodings.RealVectorEncoding/3.3/ParticleOperators/RealVectorVelocityInitializer.cs @ 15091

Last change on this file since 15091 was 15091, checked in by abeham, 7 years ago

#2797:

  • Updated PSO to make it more compatible with SPSO 2011
  • Removed truncation of velocity vector and instead rescaled it given the maximum velocity
  • Added non-zero initial velocity according to SPSO 2011
  • Removed complicated bouncing code due to box constraints and instead implemented as described in SPSO 2011
  • Calculating neighbor best has been changed to use personal best
  • Avoiding local and global particle update and instead relying on neighborbest
  • More randomization during velocity update by using a separate random numbers per dimension
  • Reusing problem specific solution creator in RealVectorParticleCreator instead of always using UniformRandomRealVectorCreator
File size: 3.6 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.Collections.Generic;
24using System.Linq;
25using System.Text;
26using System.Threading.Tasks;
27using HeuristicLab.Common;
28using HeuristicLab.Core;
29using HeuristicLab.Data;
30using HeuristicLab.Operators;
31using HeuristicLab.Optimization;
32using HeuristicLab.Parameters;
33using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
34
35namespace HeuristicLab.Encodings.RealVectorEncoding {
36  [Item("RealVectorVelocityInitializer", "Initializes the velocity vector.")]
37  [StorableClass]
38  public class RealVectorVelocityInitializer : SingleSuccessorOperator, IStochasticOperator {
39    #region Parameters
40    public ILookupParameter<IRandom> RandomParameter {
41      get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
42    }
43    public IValueLookupParameter<DoubleMatrix> BoundsParameter {
44      get { return (IValueLookupParameter<DoubleMatrix>)Parameters["Bounds"]; }
45    }
46    public ILookupParameter<RealVector> RealVectorParameter {
47      get { return (ILookupParameter<RealVector>)Parameters["RealVector"]; }
48    }
49    public ILookupParameter<RealVector> VelocityParameter {
50      get { return (ILookupParameter<RealVector>)Parameters["Velocity"]; }
51    }
52    #endregion
53   
54    #region Construction & Cloning
55    [StorableConstructor]
56    protected RealVectorVelocityInitializer(bool deserializing) : base(deserializing) { }
57    protected RealVectorVelocityInitializer(RealVectorVelocityInitializer original, Cloner cloner) : base(original, cloner) { }
58    public RealVectorVelocityInitializer()
59      : base() {
60      Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator to use."));
61      Parameters.Add(new ValueLookupParameter<DoubleMatrix>("Bounds", "The lower and upper bounds in each dimension."));
62      Parameters.Add(new LookupParameter<RealVector>("RealVector", "Particle's current solution"));
63      Parameters.Add(new LookupParameter<RealVector>("Velocity", "Particle's current velocity."));
64    }
65    public override IDeepCloneable Clone(Cloner cloner) {
66      return new RealVectorVelocityInitializer(this, cloner);
67    }
68    #endregion
69
70    public override IOperation Apply() {
71      var random = RandomParameter.ActualValue;
72      var bounds = BoundsParameter.ActualValue;
73      var position = RealVectorParameter.ActualValue;
74      var velocity = new RealVector(position.Length);
75      for (var i = 0; i < velocity.Length; i++) {
76        var lower = (bounds[i % bounds.Rows, 0] - position[i]);
77        var upper = (bounds[i % bounds.Rows, 1] - position[i]);
78        velocity[i] = lower + random.NextDouble() * (upper - lower); // SPSO 2011
79      }
80      VelocityParameter.ActualValue = velocity;
81      return base.Apply();
82    }
83  }
84}
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