source: branches/symbreg-factors-2650/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableTreeNodeBase.cs @ 14758

Last change on this file since 14758 was 14758, checked in by gkronber, 4 years ago

#2650 unified mutation behaviour for all variable tree nodes. Introduced parameter for probability of changing a variable.

File size: 3.7 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2016 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 HeuristicLab.Common;
23using HeuristicLab.Core;
24using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
25using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
26using HeuristicLab.Random;
27namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
28  [StorableClass]
29  public abstract class VariableTreeNodeBase : SymbolicExpressionTreeTerminalNode, IVariableTreeNode {
30    public new VariableBase Symbol {
31      get { return (VariableBase)base.Symbol; }
32    }
33    [Storable]
34    private double weight;
35    public double Weight {
36      get { return weight; }
37      set { weight = value; }
38    }
39    [Storable]
40    private string variableName;
41    public string VariableName {
42      get { return variableName; }
43      set { variableName = value; }
44    }
45
46    [StorableConstructor]
47    protected VariableTreeNodeBase(bool deserializing) : base(deserializing) { }
48    protected VariableTreeNodeBase(VariableTreeNodeBase original, Cloner cloner)
49      : base(original, cloner) {
50      weight = original.weight;
51      variableName = original.variableName;
52    }
53    protected VariableTreeNodeBase() { }
54    protected VariableTreeNodeBase(VariableBase variableSymbol) : base(variableSymbol) { }
55
56    public override bool HasLocalParameters {
57      get { return true; }
58    }
59
60    public override void ResetLocalParameters(IRandom random) {
61      base.ResetLocalParameters(random);
62      weight = NormalDistributedRandom.NextDouble(random, Symbol.WeightMu, Symbol.WeightSigma);
63
64#pragma warning disable 612, 618
65      variableName = Symbol.VariableNames.SelectRandom(random);
66#pragma warning restore 612, 618
67    }
68
69    public override void ShakeLocalParameters(IRandom random, double shakingFactor) {
70      base.ShakeLocalParameters(random, shakingFactor);
71      if(random.NextDouble() < 0) {
72        double x = NormalDistributedRandom.NextDouble(random, Symbol.WeightManipulatorMu, Symbol.WeightManipulatorSigma);
73        weight = weight + x * shakingFactor;
74      } else {
75        double x = NormalDistributedRandom.NextDouble(random, 1.0, Symbol.MultiplicativeWeightManipulatorSigma);
76        weight = weight * x;
77      }
78      if(Symbol.VariableChangeProbability >= 1.0 || random.NextDouble() < Symbol.VariableChangeProbability) {
79        var oldName = variableName;
80#pragma warning disable 612, 618
81        variableName = Symbol.VariableNames.SelectRandom(random);
82#pragma warning restore 612, 618
83        if(oldName != variableName) {
84          weight = NormalDistributedRandom.NextDouble(random, Symbol.WeightMu, Symbol.WeightSigma);
85        }
86      }      // 50% additive & 50% multiplicative (BUG in if statement below!)
87    }
88
89    public override string ToString() {
90      if(weight.IsAlmost(1.0)) return variableName;
91      else return weight.ToString("E4") + " " + variableName;
92    }
93  }
94}
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