Free cookie consent management tool by TermsFeed Policy Generator

source: branches/SymbolicExpressionTreeDiversityAnalyzers/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/TreeMatching/SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator.cs @ 12086

Last change on this file since 12086 was 12086, checked in by bburlacu, 9 years ago

#2326: Moved phenotypic diversity analyzers one level up (since they can be applied to both single- and multiobjective problems). Added wiring in the multiobjective problems. Changed base class to SolutionSimilarityCalculator and adjusted analyzers.

File size: 4.5 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2015 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 HeuristicLab.Common;
24using HeuristicLab.Core;
25using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
26using HeuristicLab.Optimization.Operators;
27using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
28
29namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
30  [StorableClass]
31  [Item("SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator", "A similarity calculator based on the size of the maximum common subtree between two trees")]
32  public class SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator : SolutionSimilarityCalculator {
33    [Storable]
34    private readonly SymbolicExpressionTreeNodeEqualityComparer comparer;
35    public bool MatchVariableWeights {
36      get { return comparer.MatchVariableWeights; }
37      set { comparer.MatchVariableWeights = value; }
38    }
39
40    public bool MatchConstantValues {
41      get { return comparer.MatchConstantValues; }
42      set { comparer.MatchConstantValues = value; }
43    }
44
45    protected override bool IsCommutative { get { return true; } }
46
47    [StorableConstructor]
48    protected SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator(bool deserializing) : base(deserializing) { }
49
50    public override IDeepCloneable Clone(Cloner cloner) {
51      return new SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator(this, cloner);
52    }
53
54    protected SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator(SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator original, Cloner cloner)
55      : base(original, cloner) {
56      comparer = cloner.Clone(original.comparer);
57    }
58
59    public SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator() {
60      comparer = new SymbolicExpressionTreeNodeEqualityComparer {
61        MatchConstantValues = true,
62        MatchVariableNames = true,
63        MatchVariableWeights = true
64      };
65    }
66
67    public SymbolicExpressionTreeMaxCommonSubtreeSimilarityCalculator(bool matchVariableWeights, bool matchConstantValues) {
68      comparer = new SymbolicExpressionTreeNodeEqualityComparer {
69        MatchConstantValues = matchConstantValues,
70        MatchVariableNames = true,
71        MatchVariableWeights = matchVariableWeights
72      };
73    }
74
75    public double CalculateSimilarity(ISymbolicExpressionTree t1, ISymbolicExpressionTree t2) {
76      return MaxCommonSubtreeSimilarity(t1, t2, comparer);
77    }
78
79    public override double CalculateSolutionSimilarity(IScope leftSolution, IScope rightSolution) {
80      var t1 = leftSolution.Variables[SolutionVariableName].Value as ISymbolicExpressionTree;
81      var t2 = rightSolution.Variables[SolutionVariableName].Value as ISymbolicExpressionTree;
82
83      if (t1 == null || t2 == null)
84        throw new ArgumentException("Cannot calculate similarity when one of the arguments is null.");
85
86      return MaxCommonSubtreeSimilarity(t1, t2, comparer);
87    }
88
89
90    public static double MaxCommonSubtreeSimilarity(ISymbolicExpressionTree a, ISymbolicExpressionTree b, ISymbolicExpressionTreeNodeSimilarityComparer comparer) {
91      int max = 0;
92      var rootA = a.Root.GetSubtree(0).GetSubtree(0);
93      var rootB = b.Root.GetSubtree(0).GetSubtree(0);
94      foreach (var aa in rootA.IterateNodesBreadth()) {
95        int lenA = aa.GetLength();
96        if (lenA <= max) continue;
97        foreach (var bb in rootB.IterateNodesBreadth()) {
98          int lenB = bb.GetLength();
99          if (lenB <= max) continue;
100          int matches = SymbolicExpressionTreeMatching.Match(aa, bb, comparer);
101          if (max < matches)
102            max = matches;
103        }
104      }
105      return 2.0 * max / (rootA.GetLength() + rootB.GetLength());
106    }
107  }
108}
Note: See TracBrowser for help on using the repository browser.