public static ISymbolicExpressionTree Prune(ISymbolicExpressionTree tree, SymbolicRegressionSolutionImpactValuesCalculator impactValuesCalculator, ISymbolicDataAnalysisExpressionTreeInterpreter interpreter, IRegressionProblemData problemData, DoubleLimit estimationLimits, IEnumerable<int> rows, double nodeImpactThreshold = 0.0, bool pruneOnlyZeroImpactNodes = false) { var clonedTree = (ISymbolicExpressionTree)tree.Clone(); var model = new SymbolicRegressionModel(problemData.TargetVariable, clonedTree, interpreter, estimationLimits.Lower, estimationLimits.Upper); var nodes = clonedTree.Root.GetSubtree(0).GetSubtree(0).IterateNodesPrefix().ToList(); // skip the nodes corresponding to the ProgramRootSymbol and the StartSymbol double qualityForImpactsCalculation = double.NaN; // pass a NaN value initially so the impact calculator will calculate the quality for (int i = 0; i < nodes.Count; ++i) { var node = nodes[i]; if (node is ConstantTreeNode) continue; double impactValue, replacementValue; double newQualityForImpactsCalculation; impactValuesCalculator.CalculateImpactAndReplacementValues(model, node, problemData, rows, out impactValue, out replacementValue, out newQualityForImpactsCalculation, qualityForImpactsCalculation); if (pruneOnlyZeroImpactNodes && !impactValue.IsAlmost(0.0)) continue; if (!pruneOnlyZeroImpactNodes && impactValue > nodeImpactThreshold) continue; var constantNode = (ConstantTreeNode)node.Grammar.GetSymbol("Constant").CreateTreeNode(); constantNode.Value = replacementValue; ReplaceWithConstant(node, constantNode); i += node.GetLength() - 1; // skip subtrees under the node that was folded qualityForImpactsCalculation = newQualityForImpactsCalculation; } return model.SymbolicExpressionTree; }
public static ISymbolicExpressionTree Prune(ISymbolicExpressionTree tree, SymbolicRegressionSolutionImpactValuesCalculator impactValuesCalculator, ISymbolicDataAnalysisExpressionTreeInterpreter interpreter, IRegressionProblemData problemData, DoubleLimit estimationLimits, IEnumerable <int> rows, double nodeImpactThreshold = 0.0, bool pruneOnlyZeroImpactNodes = false) { var clonedTree = (ISymbolicExpressionTree)tree.Clone(); var model = new SymbolicRegressionModel(problemData.TargetVariable, clonedTree, interpreter, estimationLimits.Lower, estimationLimits.Upper); var nodes = clonedTree.Root.GetSubtree(0).GetSubtree(0).IterateNodesPrefix().ToList(); // skip the nodes corresponding to the ProgramRootSymbol and the StartSymbol double qualityForImpactsCalculation = double.NaN; // pass a NaN value initially so the impact calculator will calculate the quality for (int i = 0; i < nodes.Count; ++i) { var node = nodes[i]; if (node is ConstantTreeNode) { continue; } double impactValue, replacementValue; double newQualityForImpactsCalculation; impactValuesCalculator.CalculateImpactAndReplacementValues(model, node, problemData, rows, out impactValue, out replacementValue, out newQualityForImpactsCalculation, qualityForImpactsCalculation); if (pruneOnlyZeroImpactNodes && !impactValue.IsAlmost(0.0)) { continue; } if (!pruneOnlyZeroImpactNodes && impactValue > nodeImpactThreshold) { continue; } var constantNode = (ConstantTreeNode)node.Grammar.GetSymbol("Constant").CreateTreeNode(); constantNode.Value = replacementValue; ReplaceWithConstant(node, constantNode); i += node.GetLength() - 1; // skip subtrees under the node that was folded qualityForImpactsCalculation = newQualityForImpactsCalculation; } return(model.SymbolicExpressionTree); }
protected SymbolicRegressionSolutionImpactValuesCalculator(SymbolicRegressionSolutionImpactValuesCalculator original, Cloner cloner) : base(original, cloner) { }