1 | #region License Information
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2 | /* HeuristicLab
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3 | * Copyright (C) Heuristic and Evolutionary Algorithms Laboratory (HEAL)
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4 | *
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5 | * This file is part of HeuristicLab.
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6 | *
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7 | * HeuristicLab is free software: you can redistribute it and/or modify
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8 | * it under the terms of the GNU General Public License as published by
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9 | * the Free Software Foundation, either version 3 of the License, or
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10 | * (at your option) any later version.
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11 | *
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12 | * HeuristicLab is distributed in the hope that it will be useful,
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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15 | * GNU General Public License for more details.
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16 | *
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17 | * You should have received a copy of the GNU General Public License
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18 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
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19 | */
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20 | #endregion
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21 |
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22 | using System;
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23 | using System.Collections.Generic;
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24 | using System.Linq;
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25 | using HEAL.Attic;
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26 | using HeuristicLab.Common;
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27 | using HeuristicLab.Core;
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28 | using HeuristicLab.Data;
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29 | using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
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30 | using HeuristicLab.Parameters;
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31 |
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32 | namespace HeuristicLab.Problems.DataAnalysis.Symbolic.Regression {
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33 | [Item("NMSE Evaluator with shape-constraints (single-objective)", "Calculates NMSE of a symbolic regression solution and checks constraints. The fitness is a combination of NMSE and constraint violations.")]
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34 | [StorableType("27473973-DD8D-4375-997D-942E2280AE8E")]
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35 | public class NMSESingleObjectiveConstraintsEvaluator : SymbolicRegressionSingleObjectiveEvaluator {
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36 | #region Parameter/Properties
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37 |
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38 | private const string OptimizeParametersParameterName = "OptimizeParameters";
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39 | private const string ParameterOptimizationIterationsParameterName = "ParameterOptimizationIterations";
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40 | private const string UseSoftConstraintsParameterName = "UseSoftConstraintsEvaluation";
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41 | private const string BoundsEstimatorParameterName = "BoundsEstimator";
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42 | private const string PenaltyFactorParameterName = "PenaltyFactor";
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43 |
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44 |
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45 | public IFixedValueParameter<BoolValue> OptimizerParametersParameter =>
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46 | (IFixedValueParameter<BoolValue>)Parameters[OptimizeParametersParameterName];
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47 |
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48 | public IFixedValueParameter<IntValue> ConstantOptimizationIterationsParameter =>
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49 | (IFixedValueParameter<IntValue>)Parameters[ParameterOptimizationIterationsParameterName];
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50 |
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51 | public IFixedValueParameter<BoolValue> UseSoftConstraintsParameter =>
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52 | (IFixedValueParameter<BoolValue>)Parameters[UseSoftConstraintsParameterName];
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53 |
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54 | public IValueParameter<IBoundsEstimator> BoundsEstimatorParameter =>
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55 | (IValueParameter<IBoundsEstimator>)Parameters[BoundsEstimatorParameterName];
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56 | public IFixedValueParameter<DoubleValue> PenaltyFactorParameter =>
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57 | (IFixedValueParameter<DoubleValue>)Parameters[PenaltyFactorParameterName];
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58 |
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59 | public bool OptimizeParameters {
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60 | get => OptimizerParametersParameter.Value.Value;
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61 | set => OptimizerParametersParameter.Value.Value = value;
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62 | }
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63 |
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64 | public int ConstantOptimizationIterations {
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65 | get => ConstantOptimizationIterationsParameter.Value.Value;
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66 | set => ConstantOptimizationIterationsParameter.Value.Value = value;
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67 | }
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68 |
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69 | public bool UseSoftConstraints {
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70 | get => UseSoftConstraintsParameter.Value.Value;
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71 | set => UseSoftConstraintsParameter.Value.Value = value;
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72 | }
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73 |
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74 | public IBoundsEstimator BoundsEstimator {
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75 | get => BoundsEstimatorParameter.Value;
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76 | set => BoundsEstimatorParameter.Value = value;
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77 | }
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78 |
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79 | public double PenalityFactor {
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80 | get => PenaltyFactorParameter.Value.Value;
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81 | set => PenaltyFactorParameter.Value.Value = value;
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82 | }
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83 |
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84 |
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85 | public override bool Maximization => false; // NMSE is minimized
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86 |
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87 | #endregion
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88 |
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89 | #region Constructors/Cloning
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90 |
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91 | [StorableConstructor]
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92 | protected NMSESingleObjectiveConstraintsEvaluator(StorableConstructorFlag _) : base(_) { }
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93 |
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94 | protected NMSESingleObjectiveConstraintsEvaluator(
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95 | NMSESingleObjectiveConstraintsEvaluator original, Cloner cloner) : base(original, cloner) { }
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96 |
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97 | public NMSESingleObjectiveConstraintsEvaluator() {
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98 | Parameters.Add(new FixedValueParameter<BoolValue>(OptimizeParametersParameterName,
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99 | "Define whether optimization of numeric parameters is active or not (default: false).", new BoolValue(false)));
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100 | Parameters.Add(new FixedValueParameter<IntValue>(ParameterOptimizationIterationsParameterName,
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101 | "Define how many parameter optimization steps should be performed (default: 10).", new IntValue(10)));
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102 | Parameters.Add(new FixedValueParameter<BoolValue>(UseSoftConstraintsParameterName,
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103 | "Define whether the constraints are penalized by soft or hard constraints (default: false).", new BoolValue(false)));
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104 | Parameters.Add(new ValueParameter<IBoundsEstimator>(BoundsEstimatorParameterName,
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105 | "The estimator which is used to estimate output ranges of models (default: interval arithmetic).", new IntervalArithBoundsEstimator()));
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106 | Parameters.Add(new FixedValueParameter<DoubleValue>(PenaltyFactorParameterName,
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107 | "Punishment factor for constraint violations for soft constraint handling (fitness = NMSE + penaltyFactor * avg(violations)) (default: 1.0)", new DoubleValue(1.0)));
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108 | }
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109 |
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110 | [StorableHook(HookType.AfterDeserialization)]
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111 | private void AfterDeserialization() { }
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112 |
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113 | public override IDeepCloneable Clone(Cloner cloner) {
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114 | return new NMSESingleObjectiveConstraintsEvaluator(this, cloner);
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115 | }
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116 |
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117 | #endregion
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118 |
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119 | public override IOperation InstrumentedApply() {
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120 | var rows = GenerateRowsToEvaluate();
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121 | var tree = SymbolicExpressionTreeParameter.ActualValue;
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122 | var problemData = ProblemDataParameter.ActualValue;
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123 | var interpreter = SymbolicDataAnalysisTreeInterpreterParameter.ActualValue;
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124 | var estimationLimits = EstimationLimitsParameter.ActualValue;
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125 | var applyLinearScaling = ApplyLinearScalingParameter.ActualValue.Value;
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126 |
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127 | var quality = Evaluate(tree, problemData, rows, interpreter, applyLinearScaling, estimationLimits.Lower, estimationLimits.Upper);
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128 | QualityParameter.ActualValue = new DoubleValue(quality);
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129 |
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130 | return base.InstrumentedApply();
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131 | }
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132 |
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133 | private static void CalcLinearScalingTerms(
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134 | ISymbolicExpressionTree tree,
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135 | IRegressionProblemData problemData,
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136 | IEnumerable<int> rows,
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137 | ISymbolicDataAnalysisExpressionTreeInterpreter interpreter) {
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138 | var rootNode = new ProgramRootSymbol().CreateTreeNode();
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139 | var startNode = new StartSymbol().CreateTreeNode();
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140 | var offset = tree.Root.GetSubtree(0) //Start
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141 | .GetSubtree(0); //Offset
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142 | var scaling = offset.GetSubtree(0);
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143 |
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144 | //Check if tree contains offset and scaling nodes
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145 | if (!(offset.Symbol is Addition) || !(scaling.Symbol is Multiplication))
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146 | throw new ArgumentException($"Shape Constraints Evaluation can only be used with LinearScalingGrammar.");
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147 |
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148 | var t = (ISymbolicExpressionTreeNode)scaling.GetSubtree(0).Clone();
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149 | rootNode.AddSubtree(startNode);
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150 | startNode.AddSubtree(t);
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151 | var newTree = new SymbolicExpressionTree(rootNode);
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152 |
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153 | //calculate alpha and beta for scaling
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154 | var estimatedValues = interpreter.GetSymbolicExpressionTreeValues(newTree, problemData.Dataset, rows);
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155 |
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156 | var targetValues = problemData.Dataset.GetDoubleValues(problemData.TargetVariable, rows);
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157 | OnlineLinearScalingParameterCalculator.Calculate(estimatedValues, targetValues, out var alpha, out var beta, out var errorState);
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158 | if (errorState == OnlineCalculatorError.None) {
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159 | //Set alpha and beta to the scaling nodes from ia grammar
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160 | var offsetParameter = offset.GetSubtree(1) as ConstantTreeNode;
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161 | offsetParameter.Value = alpha;
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162 | var scalingParameter = scaling.GetSubtree(1) as ConstantTreeNode;
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163 | scalingParameter.Value = beta;
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164 | }
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165 | }
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166 |
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167 | public static double Calculate(
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168 | ISymbolicExpressionTree tree,
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169 | IRegressionProblemData problemData, IEnumerable<int> rows,
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170 | ISymbolicDataAnalysisExpressionTreeInterpreter interpreter,
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171 | double lowerEstimationLimit, double upperEstimationLimit,
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172 | IBoundsEstimator estimator,
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173 | bool useSoftConstraints = false, double penaltyFactor = 1.0) {
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174 |
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175 | var constraints = Enumerable.Empty<ShapeConstraint>();
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176 | if (problemData is ShapeConstrainedRegressionProblemData scProbData)
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177 | constraints = scProbData.ShapeConstraints.EnabledConstraints;
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178 |
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179 | var estimatedValues = interpreter.GetSymbolicExpressionTreeValues(tree, problemData.Dataset, rows);
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180 | var boundedEstimatedValues = estimatedValues.LimitToRange(lowerEstimationLimit, upperEstimationLimit);
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181 | var targetValues = problemData.Dataset.GetDoubleValues(problemData.TargetVariable, rows);
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182 | var nmse = OnlineNormalizedMeanSquaredErrorCalculator.Calculate(targetValues, boundedEstimatedValues, out var errorState);
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183 | if (errorState != OnlineCalculatorError.None)
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184 | return 1.0;
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185 |
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186 | if (!constraints.Any())
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187 | return nmse;
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188 |
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189 | var intervalCollection = problemData.VariableRanges;
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190 | var constraintViolations = IntervalUtil.GetConstraintViolations(constraints, estimator, intervalCollection, tree);
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191 |
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192 | // infinite/NaN constraints
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193 | if (constraintViolations.Any(x => double.IsNaN(x) || double.IsInfinity(x)))
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194 | return 1.0;
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195 |
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196 | // hard constraints
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197 | if (!useSoftConstraints) {
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198 | if (constraintViolations.Any(x => x > 0.0))
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199 | return 1.0;
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200 | return nmse;
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201 | }
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202 |
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203 | // soft constraints
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204 | if (penaltyFactor < 0.0)
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205 | throw new ArgumentException("The parameter has to be >= 0.0.", nameof(penaltyFactor));
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206 |
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207 | var weightedViolationsAvg = constraints
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208 | .Zip(constraintViolations, (c, v) => c.Weight * v)
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209 | .Average();
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210 |
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211 | return Math.Min(nmse, 1.0) + penaltyFactor * weightedViolationsAvg;
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212 | }
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213 |
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214 | public override double Evaluate(
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215 | IExecutionContext context, ISymbolicExpressionTree tree, IRegressionProblemData problemData,
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216 | IEnumerable<int> rows) {
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217 | SymbolicDataAnalysisTreeInterpreterParameter.ExecutionContext = context;
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218 | EstimationLimitsParameter.ExecutionContext = context;
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219 | ApplyLinearScalingParameter.ExecutionContext = context;
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220 |
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221 | var nmse = Calculate(
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222 | tree, problemData, rows,
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223 | SymbolicDataAnalysisTreeInterpreterParameter.ActualValue,
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224 | EstimationLimitsParameter.ActualValue.Lower,
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225 | EstimationLimitsParameter.ActualValue.Upper,
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226 | BoundsEstimator,
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227 | UseSoftConstraints,
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228 | PenalityFactor);
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229 |
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230 | SymbolicDataAnalysisTreeInterpreterParameter.ExecutionContext = null;
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231 | EstimationLimitsParameter.ExecutionContext = null;
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232 | ApplyLinearScalingParameter.ExecutionContext = null;
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233 |
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234 | return nmse;
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235 | }
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236 |
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237 | public override double Evaluate(
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238 | ISymbolicExpressionTree tree,
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239 | IRegressionProblemData problemData,
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240 | IEnumerable<int> rows,
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241 | ISymbolicDataAnalysisExpressionTreeInterpreter interpreter,
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242 | bool applyLinearScaling = true,
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243 | double lowerEstimationLimit = double.MinValue,
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244 | double upperEstimationLimit = double.MaxValue) {
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245 |
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246 | if (OptimizeParameters)
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247 | SymbolicRegressionConstantOptimizationEvaluator.OptimizeConstants(
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248 | interpreter, tree,
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249 | problemData, rows,
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250 | applyLinearScaling: false, // Tree already contains scaling terms
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251 | ConstantOptimizationIterations,
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252 | updateVariableWeights: true,
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253 | lowerEstimationLimit,
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254 | upperEstimationLimit);
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255 |
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256 | else if (applyLinearScaling) // extra scaling terms, which are included in tree
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257 | CalcLinearScalingTerms(tree, problemData, rows, interpreter);
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258 |
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259 | return Calculate(
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260 | tree, problemData,
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261 | rows, interpreter,
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262 | lowerEstimationLimit,
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263 | upperEstimationLimit,
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264 | BoundsEstimator,
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265 | UseSoftConstraints,
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266 | PenalityFactor);
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267 | }
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268 | }
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269 | } |
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