source: trunk/sources/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisModelComplexityCalculator.cs @ 14826

Last change on this file since 14826 was 14826, checked in by gkronber, 6 months ago

#2650: merged the factors branch into trunk

File size: 3.6 KB
Line 
1#region License Information
2
3/* HeuristicLab
4 * Copyright (C) 2002-2016 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
5 *
6 * This file is part of HeuristicLab.
7 *
8 * HeuristicLab is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or
11 * (at your option) any later version.
12 *
13 * HeuristicLab is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#endregion
23
24using System;
25using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
26
27namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
28  public static class SymbolicDataAnalysisModelComplexityCalculator {
29    public static double CalculateComplexity(ISymbolicExpressionTree tree) {
30      return CalculateComplexity(tree.Root);
31    }
32    public static double CalculateComplexity(ISymbolicExpressionTreeNode treeNode) {
33      var node = treeNode;
34      if (node.Symbol is ProgramRootSymbol) node = node.GetSubtree(0);
35      if (node.Symbol is StartSymbol) node = node.GetSubtree(0);
36
37      switch (OpCodes.MapSymbolToOpCode(node)) {
38        case OpCodes.Constant: {
39            return 1;
40          }
41        case OpCodes.Variable:
42        case OpCodes.BinaryFactorVariable:
43        case OpCodes.FactorVariable: {
44            return 2;
45          }
46        case OpCodes.Add:
47        case OpCodes.Sub: {
48            double complexity = 0;
49            for (int i = 0; i < node.SubtreeCount; i++) {
50              complexity += CalculateComplexity(node.GetSubtree(i));
51            }
52            return complexity;
53          }
54        case OpCodes.Mul:
55        case OpCodes.Div: {
56            double complexity = 1;
57            for (int i = 0; i < node.SubtreeCount; i++) {
58              var nodeComplexity = CalculateComplexity(node.GetSubtree(i));
59              complexity *= nodeComplexity + 1;
60            }
61            return complexity;
62          }
63        case OpCodes.Sin:
64        case OpCodes.Cos:
65        case OpCodes.Tan:
66        case OpCodes.Exp:
67        case OpCodes.Log: {
68            double complexity = CalculateComplexity(node.GetSubtree(0));
69            return Math.Pow(2.0, complexity);
70          }
71        case OpCodes.Square: {
72            double complexity = CalculateComplexity(node.GetSubtree(0));
73            return complexity * complexity;
74          }
75        case OpCodes.SquareRoot: {
76            double complexity = CalculateComplexity(node.GetSubtree(0));
77            return complexity * complexity * complexity;
78          }
79        case OpCodes.Power:
80        case OpCodes.Root: {
81            double complexity = CalculateComplexity(node.GetSubtree(0));
82            var exponent = node.GetSubtree(1) as ConstantTreeNode;
83            if (exponent != null) {
84              double expVal = exponent.Value;
85              if (expVal < 0) expVal = Math.Abs(expVal);
86              if (expVal < 1) expVal = 1 / expVal;
87              return Math.Pow(complexity, Math.Round(expVal));
88            }
89
90            double expComplexity = CalculateComplexity(node.GetSubtree(1));
91            return Math.Pow(complexity, 2 * expComplexity);
92          }
93
94        default:
95          throw new NotSupportedException();
96      }
97    }
98  }
99}
Note: See TracBrowser for help on using the repository browser.