source: branches/HeuristicLab.EvolutionTracking/HeuristicLab.EvolutionTracking/3.4/Operators/BeforeManipulatorOperator.cs @ 10886

Last change on this file since 10886 was 10886, checked in by bburlacu, 8 years ago

#1772: Simplified GenealogyGraph (and related components) API in an effort to improve speed and memory consumption (eg., by sharing the same arc when walking the graph in both directions: parent-child and child-parent).

File size: 3.6 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2014 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.Collections.Generic;
23using System.Linq;
24using HeuristicLab.Common;
25using HeuristicLab.Core;
26using HeuristicLab.Parameters;
27using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
28
29namespace HeuristicLab.EvolutionTracking {
30  [StorableClass]
31  [Item("AfterCrossoverOperator", "Performs an action after the crossover operator is applied.")]
32  public class BeforeManipulatorOperator<T> : EvolutionTrackingOperator<T>, IManipulatorOperator<T> where T : class,IItem {
33
34    private const string ChildParameterName = "Child";
35
36    public ILookupParameter<T> ChildParameter {
37      get { return (ILookupParameter<T>)Parameters[ChildParameterName]; }
38    }
39
40    protected BeforeManipulatorOperator(BeforeManipulatorOperator<T> original, Cloner cloner)
41      : base(original, cloner) {
42    }
43    public override IDeepCloneable Clone(Cloner cloner) {
44      return new BeforeManipulatorOperator<T>(this, cloner);
45    }
46
47    public BeforeManipulatorOperator() {
48      Parameters.Add(new LookupParameter<T>(ChildParameterName));
49    }
50
51    public override IOperation Apply() {
52      if (GenealogyGraph.Contains(ChildParameter.ActualValue)) {
53        // if the graph already contains a vertex representing the child, it means that the child is a product of crossover
54        // when mutation follows after crossover, some changes need to be made to the graph to maintain consistency
55        var child = ChildParameter.ActualValue;
56        var clone = (T)child.Clone();
57        var vChild = (IGenealogyGraphNode<T>)GenealogyGraph[child];
58        var vClone = new GenealogyGraphNode<T> { Content = clone, Rank = vChild.Rank - 0.5 };
59        GenealogyGraph.AddVertex(vClone);
60        var parents = vChild.Parents; // parents of child become parents of clone
61        foreach (var p in parents) {
62          var arc = p.OutArcs.First(a => a.Target == vChild);
63          arc.Target = vClone;
64          vClone.AddReverseArc(arc);
65        }
66
67        vClone.InArcs.Last().Data = vChild.InArcs.Last().Data; // fragment of child becomes fragment of clone
68        vChild.InArcs = new List<IGenealogyGraphArc>(); // child will be connected to clone
69        GenealogyGraph.AddArc(vClone, vChild);
70
71        // the following step in necessary because some mutation operators change values while the reference stays the same
72        // so we clone in order to prevent mutations to be "shadowed" in the parent
73        var parent = vClone.Parents.First();
74        parent.Content = (T)parent.Content.Clone();
75        GenealogyGraph[parent.Content] = parent;
76
77      } else { // this needs to be checked
78        var vChild = new GenealogyGraphNode<T> { Content = ChildParameter.ActualValue, Rank = Generations.Value };
79        GenealogyGraph.AddVertex(vChild);
80      }
81      return base.Apply();
82    }
83  }
84}
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