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source: trunk/sources/HeuristicLab.Encodings.RealVectorEncoding/3.3/ParticleOperators/RealVectorNeighborhoodParticleUpdater.cs @ 15096

Last change on this file since 15096 was 15096, checked in by abeham, 7 years ago

#2797:

  • Added SPSO 2007 and SPSO 2011 particle updaters
  • Unhide particle updater parameter
  • Changed default parameters of sample
  • Changed max velocity to very high value by default (no speed limit)
  • Adapted unit test
File size: 4.0 KB
RevLine 
[5560]1#region License Information
2/* HeuristicLab
[14185]3 * Copyright (C) 2002-2016 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
[5560]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
[15096]22using System;
[5560]23using HeuristicLab.Common;
24using HeuristicLab.Core;
25using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
[15096]26using HeuristicLab.PluginInfrastructure;
[5560]27
28namespace HeuristicLab.Encodings.RealVectorEncoding {
29  [Item("Neighborhood Particle Updater", "Updates the particle's position using (among other things) the best neighbor's position. Point = Point + Velocity*Inertia + (PersonalBestPoint-Point)*Phi_P*r_p + (BestNeighborPoint-Point)*Phi_G*r_g.")]
30  [StorableClass]
[15096]31  [NonDiscoverableType]
32  [Obsolete("Replaced by SPSO2007ParticleUpdater")]
33  internal sealed class RealVectorNeighborhoodParticleUpdater : RealVectorParticleUpdater {
[5560]34
[5592]35    #region Construction & Cloning
[5560]36    [StorableConstructor]
37    private RealVectorNeighborhoodParticleUpdater(bool deserializing) : base(deserializing) { }
38    private RealVectorNeighborhoodParticleUpdater(RealVectorNeighborhoodParticleUpdater original, Cloner cloner) : base(original, cloner) { }
39    public RealVectorNeighborhoodParticleUpdater() : base() { }
40    public override IDeepCloneable Clone(Cloner cloner) {
41      return new RealVectorNeighborhoodParticleUpdater(this, cloner);
42    }
[5592]43    #endregion
[5560]44
[15096]45    private void UpdateVelocity() {
46      var velocity = VelocityParameter.ActualValue;
47      var position = RealVectorParameter.ActualValue;
48      var inertia = CurrentInertiaParameter.ActualValue.Value;
49      var personalBest = PersonalBestParameter.ActualValue;
50      var personalBestAttraction = PersonalBestAttractionParameter.ActualValue.Value;
51      var neighborBest = NeighborBestParameter.ActualValue;
52      var neighborBestAttraction = NeighborBestAttractionParameter.ActualValue.Value;
53
54      var random = RandomParameter.ActualValue;
55
56      for (int i = 0; i < velocity.Length; i++) {
57        double r_p = random.NextDouble();
58        double r_g = random.NextDouble();
59        velocity[i] =
60          velocity[i] * inertia +
61          (personalBest[i] - position[i]) * personalBestAttraction * r_p +
62          (neighborBest[i] - position[i]) * neighborBestAttraction * r_g;
63      }
64
65      var maxVelocity = CurrentMaxVelocityParameter.ActualValue.Value;
66      var speed = Math.Sqrt(velocity.DotProduct(velocity));
67      if (speed > maxVelocity) {
68        for (var i = 0; i < velocity.Length; i++) {
69          velocity[i] *= maxVelocity / speed;
70        }
71      }
72    }
73
74    private void UpdatePosition() {
75      var velocity = VelocityParameter.ActualValue;
76      var position = RealVectorParameter.ActualValue;
77
78      for (int i = 0; i < velocity.Length; i++) {
79        position[i] += velocity[i];
80      }
81
82      var bounds = BoundsParameter.ActualValue;
83      for (int i = 0; i < position.Length; i++) {
84        double min = bounds[i % bounds.Rows, 0];
85        double max = bounds[i % bounds.Rows, 1];
86        if (position[i] < min) {
87          position[i] = min;
88          velocity[i] = -0.5 * velocity[i]; // SPSO 2011
89        }
90        if (position[i] > max) {
91          position[i] = max;
92          velocity[i] = -0.5 * velocity[i]; // SPSO 2011
93        }
94      }
95    }
96
[5560]97    public override IOperation Apply() {
[15091]98      UpdateVelocity();
99      UpdatePosition();
[5592]100
[5560]101      return base.Apply();
102    }
103  }
104}
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