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source: branches/GP-MoveOperators/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/ReplaceBranchMoveEvaluator.cs @ 8292

Last change on this file since 8292 was 8292, checked in by gkronber, 10 years ago

#1847: worked on move operators. version of the final EMSS submission

File size: 5.8 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2012 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.Linq;
23using HeuristicLab.Common;
24using HeuristicLab.Core;
25using HeuristicLab.Data;
26using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
27using HeuristicLab.Operators;
28using HeuristicLab.Parameters;
29using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
30
31namespace HeuristicLab.Problems.DataAnalysis.Symbolic.Regression {
32  [Item("ReplaceBranchMoveEvaluator", "")]
33  [StorableClass]
34  public class ReplaceBranchMoveEvaluator : SingleSuccessorOperator, ISymbolicRegressionMoveEvaluator {
35
36    public override bool CanChangeName {
37      get { return false; }
38    }
39
40    public ILookupParameter<ReplaceBranchMove> MoveParameter {
41      get { return (ILookupParameter<ReplaceBranchMove>)Parameters["ReplaceBranchMove"]; }
42    }
43    public ILookupParameter<DoubleValue> QualityParameter {
44      get { return (ILookupParameter<DoubleValue>)Parameters["Quality"]; }
45    }
46
47    public ILookupParameter<DoubleValue> MoveQualityParameter {
48      get { return (ILookupParameter<DoubleValue>)Parameters["MoveQuality"]; }
49    }
50
51    public ILookupParameter<ISymbolicRegressionSingleObjectiveEvaluator> EvaluatorParameter {
52      get { return (ILookupParameter<ISymbolicRegressionSingleObjectiveEvaluator>)Parameters["Evaluator"]; }
53    }
54    public ILookupParameter<IRegressionProblemData> ProblemDataParameter {
55      get { return (ILookupParameter<IRegressionProblemData>)Parameters["ProblemData"]; }
56    }
57    public ILookupParameter<IntRange> FitnessCalculationPartitionParameter {
58      get { return (ILookupParameter<IntRange>)Parameters["FitnessCalculationPartition"]; }
59    }
60
61    public ILookupParameter<ISymbolicExpressionTree> SymbolicExpressionTreeParameter {
62      get { return (ILookupParameter<ISymbolicExpressionTree>)Parameters["SymbolicExpressionTree"]; }
63    }
64    [StorableConstructor]
65    protected ReplaceBranchMoveEvaluator(bool deserializing) : base(deserializing) { }
66    protected ReplaceBranchMoveEvaluator(ReplaceBranchMoveEvaluator original, Cloner cloner) : base(original, cloner) { }
67    public ReplaceBranchMoveEvaluator()
68      : base() {
69      Parameters.Add(new LookupParameter<DoubleValue>("Quality", "The quality of a symbolic regression solution."));
70      Parameters.Add(new LookupParameter<DoubleValue>("MoveQuality", "The evaluated quality of a move on a symbolic regression solution."));
71      Parameters.Add(new LookupParameter<ISymbolicRegressionSingleObjectiveEvaluator>("Evaluator", ""));
72      Parameters.Add(new LookupParameter<ReplaceBranchMove>("ReplaceBranchMove", ""));
73      Parameters.Add(new LookupParameter<IRegressionProblemData>("ProblemData", ""));
74      Parameters.Add(new LookupParameter<IntRange>("FitnessCalculationPartition", ""));
75      Parameters.Add(new LookupParameter<ISymbolicExpressionTree>("SymbolicExpressionTree", ""));
76    }
77
78    public override IOperation Apply() {
79      var evaluator = EvaluatorParameter.ActualValue;
80
81      var move = MoveParameter.ActualValue;
82
83      // calculate linear scaling
84      OnlineCalculatorError errorState;
85      double alpha, beta;
86      OnlineLinearScalingParameterCalculator.Calculate(move.NewOutput, move.OriginalOutput, out alpha, out beta, out errorState);
87
88      // prevent scaling to a constant value
89      if (beta.IsAlmost(0.0)) beta = 1.0;
90
91      move.Alpha = alpha;
92      move.Beta = beta;
93
94      var oldBranch = move.Parent.GetSubtree(move.SubtreeIndex);
95      move.Parent.RemoveSubtree(move.SubtreeIndex);
96      move.Parent.InsertSubtree(move.SubtreeIndex, Scale(move.NewBranch, alpha, beta));
97
98      var problemData = ProblemDataParameter.ActualValue;
99      IExecutionContext childContext = (IExecutionContext)ExecutionContext.CreateChildOperation(evaluator);
100
101      var fitnessPartition = FitnessCalculationPartitionParameter.ActualValue;
102      var rows = Enumerable.Range(fitnessPartition.Start, fitnessPartition.End - fitnessPartition.Start);
103      var quality = evaluator.Evaluate(childContext, move.Tree, problemData, rows);
104
105      // revert changes to tree
106      move.Parent.RemoveSubtree(move.SubtreeIndex);
107      move.Parent.InsertSubtree(move.SubtreeIndex, oldBranch);
108
109      MoveQualityParameter.ActualValue = new DoubleValue(quality);
110      return base.Apply();
111    }
112
113    private Addition add = new Addition();
114    private Multiplication mul = new Multiplication();
115    private Constant constant = new Constant();
116
117    private ISymbolicExpressionTreeNode Scale(ISymbolicExpressionTreeNode node, double alpha, double beta) {
118      var constAlpha = (ConstantTreeNode)constant.CreateTreeNode();
119      var constBeta = (ConstantTreeNode)constant.CreateTreeNode();
120      constAlpha.Value = alpha;
121      constBeta.Value = beta;
122      var sum = add.CreateTreeNode();
123      var prod = mul.CreateTreeNode();
124      prod.AddSubtree(node); prod.AddSubtree(constBeta);
125      sum.AddSubtree(prod); sum.AddSubtree(constAlpha);
126      return sum;
127    }
128
129    public override IDeepCloneable Clone(Cloner cloner) {
130      return new ReplaceBranchMoveEvaluator(this, cloner);
131    }
132  }
133}
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