source: branches/PersistenceOverhaul/HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.4/Analyzers/SymbolicExpressionSymbolFrequencyAnalyzer.cs @ 13368

Last change on this file since 13368 was 13368, checked in by ascheibe, 4 years ago

#2520 added guids to storable classes

File size: 7.5 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 System.Collections.Generic;
24using System.Linq;
25using HeuristicLab.Analysis;
26using HeuristicLab.Common;
27using HeuristicLab.Core;
28using HeuristicLab.Data;
29using HeuristicLab.Operators;
30using HeuristicLab.Optimization;
31using HeuristicLab.Parameters;
32using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
33
34namespace HeuristicLab.Encodings.SymbolicExpressionTreeEncoding {
35  /// <summary>
36  /// An operator that tracks the frequencies of distinct symbols in symbolic expression trees.
37  /// </summary>
38  [Item("SymbolicExpressionSymbolFrequencyAnalyzer", "An operator that tracks frequencies of symbols in symbolic expression trees.")]
39  [StorableClass("29CBFC73-BB85-4583-B18C-5632F2D46004")]
40  public class SymbolicExpressionSymbolFrequencyAnalyzer : SingleSuccessorOperator, ISymbolicExpressionTreeAnalyzer {
41    private const string SymbolicExpressionTreeParameterName = "SymbolicExpressionTree";
42    private const string ResultsParameterName = "Results";
43    private const string SymbolFrequenciesParameterName = "SymbolFrequencies";
44    private const string AggregateSymbolsWithDifferentSubtreeCountParameterName = "AggregateSymbolsWithDifferentSubtreeCount";
45
46    #region parameter properties
47    public IScopeTreeLookupParameter<ISymbolicExpressionTree> SymbolicExpressionTreeParameter {
48      get { return (IScopeTreeLookupParameter<ISymbolicExpressionTree>)Parameters[SymbolicExpressionTreeParameterName]; }
49    }
50    public ILookupParameter<DataTable> SymbolFrequenciesParameter {
51      get { return (ILookupParameter<DataTable>)Parameters[SymbolFrequenciesParameterName]; }
52    }
53    public ILookupParameter<ResultCollection> ResultsParameter {
54      get { return (ILookupParameter<ResultCollection>)Parameters[ResultsParameterName]; }
55    }
56    public IValueParameter<BoolValue> AggregateSymbolsWithDifferentSubtreeCountParameter {
57      get { return (IValueParameter<BoolValue>)Parameters[AggregateSymbolsWithDifferentSubtreeCountParameterName]; }
58    }
59    #endregion
60    #region properties
61    public virtual bool EnabledByDefault {
62      get { return true; }
63    }
64    public BoolValue AggregrateSymbolsWithDifferentSubtreeCount {
65      get { return AggregateSymbolsWithDifferentSubtreeCountParameter.Value; }
66      set { AggregateSymbolsWithDifferentSubtreeCountParameter.Value = value; }
67    }
68    #endregion
69
70    [StorableConstructor]
71    protected SymbolicExpressionSymbolFrequencyAnalyzer(bool deserializing) : base(deserializing) { }
72    protected SymbolicExpressionSymbolFrequencyAnalyzer(SymbolicExpressionSymbolFrequencyAnalyzer original, Cloner cloner) : base(original, cloner) { }
73    public SymbolicExpressionSymbolFrequencyAnalyzer()
74      : base() {
75      Parameters.Add(new ScopeTreeLookupParameter<ISymbolicExpressionTree>(SymbolicExpressionTreeParameterName, "The symbolic expression trees to analyze."));
76      Parameters.Add(new LookupParameter<DataTable>(SymbolFrequenciesParameterName, "The data table to store the symbol frequencies."));
77      Parameters.Add(new LookupParameter<ResultCollection>(ResultsParameterName, "The result collection where the symbol frequencies should be stored."));
78      Parameters.Add(new ValueParameter<BoolValue>(AggregateSymbolsWithDifferentSubtreeCountParameterName, "Flag that indicates if the frequencies of symbols with the same name but different number of sub-trees should be aggregated.", new BoolValue(true)));
79    }
80    public override IDeepCloneable Clone(Cloner cloner) {
81      return new SymbolicExpressionSymbolFrequencyAnalyzer(this, cloner);
82    }
83
84    [StorableHook(HookType.AfterDeserialization)]
85    private void AfterDeserialization() {
86      #region remove with HL 3.4
87      if (!Parameters.ContainsKey(AggregateSymbolsWithDifferentSubtreeCountParameterName))
88        Parameters.Add(new ValueParameter<BoolValue>(AggregateSymbolsWithDifferentSubtreeCountParameterName, "Flag that indicates if the frequencies of symbols with the same name but different number of sub-trees should be aggregated.", new BoolValue(true)));
89      #endregion
90    }
91
92    public override IOperation Apply() {
93      ItemArray<ISymbolicExpressionTree> expressions = SymbolicExpressionTreeParameter.ActualValue;
94      ResultCollection results = ResultsParameter.ActualValue;
95      DataTable symbolFrequencies = SymbolFrequenciesParameter.ActualValue;
96      if (symbolFrequencies == null) {
97        symbolFrequencies = new DataTable("Symbol frequencies", "Relative frequency of symbols aggregated over the whole population.");
98        symbolFrequencies.VisualProperties.YAxisTitle = "Relative Symbol Frequency";
99
100        SymbolFrequenciesParameter.ActualValue = symbolFrequencies;
101        results.Add(new Result("Symbol frequencies", symbolFrequencies));
102      }
103
104      // all rows must have the same number of values so we can just take the first
105      int numberOfValues = symbolFrequencies.Rows.Select(r => r.Values.Count).DefaultIfEmpty().First();
106
107      foreach (var pair in SymbolicExpressionSymbolFrequencyAnalyzer.CalculateSymbolFrequencies(expressions, AggregrateSymbolsWithDifferentSubtreeCount.Value)) {
108        if (!symbolFrequencies.Rows.ContainsKey(pair.Key)) {
109          // initialize a new row for the symbol and pad with zeros
110          DataRow row = new DataRow(pair.Key, "", Enumerable.Repeat(0.0, numberOfValues));
111          row.VisualProperties.StartIndexZero = true;
112          symbolFrequencies.Rows.Add(row);
113        }
114        symbolFrequencies.Rows[pair.Key].Values.Add(Math.Round(pair.Value, 3));
115      }
116
117      // add a zero for each data row that was not modified in the previous loop
118      foreach (var row in symbolFrequencies.Rows.Where(r => r.Values.Count != numberOfValues + 1))
119        row.Values.Add(0.0);
120
121      return base.Apply();
122    }
123
124    public static IEnumerable<KeyValuePair<string, double>> CalculateSymbolFrequencies(IEnumerable<ISymbolicExpressionTree> trees, bool aggregateDifferentNumberOfSubtrees = true) {
125      Dictionary<string, double> symbolFrequencies = new Dictionary<string, double>();
126      int totalNumberOfSymbols = 0;
127
128      foreach (var tree in trees) {
129        foreach (var node in tree.IterateNodesPrefix()) {
130          string symbolName;
131          if (aggregateDifferentNumberOfSubtrees) symbolName = node.Symbol.Name;
132          else symbolName = node.Symbol.Name + "-" + node.SubtreeCount;
133          if (symbolFrequencies.ContainsKey(symbolName)) symbolFrequencies[symbolName] += 1;
134          else symbolFrequencies.Add(symbolName, 1);
135          totalNumberOfSymbols++;
136        }
137      }
138
139      foreach (var pair in symbolFrequencies)
140        yield return new KeyValuePair<string, double>(pair.Key, pair.Value / totalNumberOfSymbols);
141    }
142  }
143}
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