private static void FillExtensionLengths(TreeExtensionPoint extension, int maxDepth) { var grammar = extension.Parent.Grammar; int maxLength = int.MinValue; int minLength = int.MaxValue; foreach (ISymbol s in grammar.GetAllowedChildSymbols(extension.Parent.Symbol, extension.ChildIndex)) { if (s.InitialFrequency > 0.0) { int max = grammar.GetMaximumExpressionLength(s, maxDepth - extension.ExtensionPointDepth); maxLength = Math.Max(maxLength, max); int min = grammar.GetMinimumExpressionLength(s); minLength = Math.Min(minLength, min); } } extension.MaximumExtensionLength = maxLength; extension.MinimumExtensionLength = minLength; }
private static bool TryCreateFullTreeFromSeed(IRandom random, ISymbolicExpressionTreeNode root, int targetLength, int maxDepth) { List<TreeExtensionPoint> extensionPoints = new List<TreeExtensionPoint>(); int currentLength = 0; int actualArity = SampleArity(random, root, targetLength, maxDepth); if (actualArity < 0) return false; for (int i = 0; i < actualArity; i++) { // insert a dummy sub-tree and add the pending extension to the list var dummy = new SymbolicExpressionTreeNode(); root.AddSubtree(dummy); var x = new TreeExtensionPoint { Parent = root, ChildIndex = i, ExtensionPointDepth = 0 }; FillExtensionLengths(x, maxDepth); extensionPoints.Add(x); } //necessary to use long data type as the extension point length could be int.MaxValue long minExtensionPointsLength = extensionPoints.Select(x => (long)x.MinimumExtensionLength).Sum(); long maxExtensionPointsLength = extensionPoints.Select(x => (long)x.MaximumExtensionLength).Sum(); // while there are pending extension points and we have not reached the limit of adding new extension points while (extensionPoints.Count > 0 && minExtensionPointsLength + currentLength <= targetLength) { int randomIndex = random.Next(extensionPoints.Count); TreeExtensionPoint nextExtension = extensionPoints[randomIndex]; extensionPoints.RemoveAt(randomIndex); ISymbolicExpressionTreeNode parent = nextExtension.Parent; int argumentIndex = nextExtension.ChildIndex; int extensionDepth = nextExtension.ExtensionPointDepth; if (parent.Grammar.GetMinimumExpressionDepth(parent.Symbol) > maxDepth - extensionDepth) { ReplaceWithMinimalTree(random, root, parent, argumentIndex); int insertedTreeLength = parent.GetSubtree(argumentIndex).GetLength(); currentLength += insertedTreeLength; minExtensionPointsLength -= insertedTreeLength; maxExtensionPointsLength -= insertedTreeLength; } else { //remove currently chosen extension point from calculation minExtensionPointsLength -= nextExtension.MinimumExtensionLength; maxExtensionPointsLength -= nextExtension.MaximumExtensionLength; var symbols = from s in parent.Grammar.GetAllowedChildSymbols(parent.Symbol, argumentIndex) where s.InitialFrequency > 0.0 where parent.Grammar.GetMinimumExpressionDepth(s) <= maxDepth - extensionDepth where parent.Grammar.GetMinimumExpressionLength(s) <= targetLength - currentLength - minExtensionPointsLength select s; if (maxExtensionPointsLength < targetLength - currentLength) symbols = from s in symbols where parent.Grammar.GetMaximumExpressionLength(s, maxDepth - extensionDepth) >= targetLength - currentLength - maxExtensionPointsLength select s; var allowedSymbols = symbols.ToList(); if (allowedSymbols.Count == 0) return false; var weights = allowedSymbols.Select(x => x.InitialFrequency).ToList(); #pragma warning disable 612, 618 var selectedSymbol = allowedSymbols.SelectRandom(weights, random); #pragma warning restore 612, 618 ISymbolicExpressionTreeNode newTree = selectedSymbol.CreateTreeNode(); if (newTree.HasLocalParameters) newTree.ResetLocalParameters(random); parent.RemoveSubtree(argumentIndex); parent.InsertSubtree(argumentIndex, newTree); var topLevelNode = newTree as SymbolicExpressionTreeTopLevelNode; if (topLevelNode != null) topLevelNode.SetGrammar((ISymbolicExpressionTreeGrammar)root.Grammar.Clone()); currentLength++; actualArity = SampleArity(random, newTree, targetLength - currentLength, maxDepth - extensionDepth); if (actualArity < 0) return false; for (int i = 0; i < actualArity; i++) { // insert a dummy sub-tree and add the pending extension to the list var dummy = new SymbolicExpressionTreeNode(); newTree.AddSubtree(dummy); var x = new TreeExtensionPoint { Parent = newTree, ChildIndex = i, ExtensionPointDepth = extensionDepth + 1 }; FillExtensionLengths(x, maxDepth); extensionPoints.Add(x); maxExtensionPointsLength += x.MaximumExtensionLength; minExtensionPointsLength += x.MinimumExtensionLength; } } } // fill all pending extension points while (extensionPoints.Count > 0) { int randomIndex = random.Next(extensionPoints.Count); TreeExtensionPoint nextExtension = extensionPoints[randomIndex]; extensionPoints.RemoveAt(randomIndex); ISymbolicExpressionTreeNode parent = nextExtension.Parent; int a = nextExtension.ChildIndex; ReplaceWithMinimalTree(random, root, parent, a); } return true; }
private static bool TryCreateFullTreeFromSeed(IRandom random, ISymbolicExpressionTreeNode root, int targetLength, int maxDepth) { List <TreeExtensionPoint> extensionPoints = new List <TreeExtensionPoint>(); int currentLength = 0; int actualArity = SampleArity(random, root, targetLength, maxDepth); if (actualArity < 0) { return(false); } for (int i = 0; i < actualArity; i++) { // insert a dummy sub-tree and add the pending extension to the list var dummy = new SymbolicExpressionTreeNode(); root.AddSubtree(dummy); var x = new TreeExtensionPoint { Parent = root, ChildIndex = i, ExtensionPointDepth = 0 }; FillExtensionLengths(x, maxDepth); extensionPoints.Add(x); } //necessary to use long data type as the extension point length could be int.MaxValue long minExtensionPointsLength = extensionPoints.Select(x => (long)x.MinimumExtensionLength).Sum(); long maxExtensionPointsLength = extensionPoints.Select(x => (long)x.MaximumExtensionLength).Sum(); // while there are pending extension points and we have not reached the limit of adding new extension points while (extensionPoints.Count > 0 && minExtensionPointsLength + currentLength <= targetLength) { int randomIndex = random.Next(extensionPoints.Count); TreeExtensionPoint nextExtension = extensionPoints[randomIndex]; extensionPoints.RemoveAt(randomIndex); ISymbolicExpressionTreeNode parent = nextExtension.Parent; int argumentIndex = nextExtension.ChildIndex; int extensionDepth = nextExtension.ExtensionPointDepth; if (parent.Grammar.GetMinimumExpressionDepth(parent.Symbol) > maxDepth - extensionDepth) { ReplaceWithMinimalTree(random, root, parent, argumentIndex); int insertedTreeLength = parent.GetSubtree(argumentIndex).GetLength(); currentLength += insertedTreeLength; minExtensionPointsLength -= insertedTreeLength; maxExtensionPointsLength -= insertedTreeLength; } else { //remove currently chosen extension point from calculation minExtensionPointsLength -= nextExtension.MinimumExtensionLength; maxExtensionPointsLength -= nextExtension.MaximumExtensionLength; var symbols = from s in parent.Grammar.GetAllowedChildSymbols(parent.Symbol, argumentIndex) where s.InitialFrequency > 0.0 where parent.Grammar.GetMinimumExpressionDepth(s) <= maxDepth - extensionDepth where parent.Grammar.GetMinimumExpressionLength(s) <= targetLength - currentLength - minExtensionPointsLength select s; if (maxExtensionPointsLength < targetLength - currentLength) { symbols = from s in symbols where parent.Grammar.GetMaximumExpressionLength(s, maxDepth - extensionDepth) >= targetLength - currentLength - maxExtensionPointsLength select s; } var allowedSymbols = symbols.ToList(); if (allowedSymbols.Count == 0) { return(false); } var weights = allowedSymbols.Select(x => x.InitialFrequency).ToList(); #pragma warning disable 612, 618 var selectedSymbol = allowedSymbols.SelectRandom(weights, random); #pragma warning restore 612, 618 ISymbolicExpressionTreeNode newTree = selectedSymbol.CreateTreeNode(); if (newTree.HasLocalParameters) { newTree.ResetLocalParameters(random); } parent.RemoveSubtree(argumentIndex); parent.InsertSubtree(argumentIndex, newTree); var topLevelNode = newTree as SymbolicExpressionTreeTopLevelNode; if (topLevelNode != null) { topLevelNode.SetGrammar((ISymbolicExpressionTreeGrammar)root.Grammar.Clone()); } currentLength++; actualArity = SampleArity(random, newTree, targetLength - currentLength, maxDepth - extensionDepth); if (actualArity < 0) { return(false); } for (int i = 0; i < actualArity; i++) { // insert a dummy sub-tree and add the pending extension to the list var dummy = new SymbolicExpressionTreeNode(); newTree.AddSubtree(dummy); var x = new TreeExtensionPoint { Parent = newTree, ChildIndex = i, ExtensionPointDepth = extensionDepth + 1 }; FillExtensionLengths(x, maxDepth); extensionPoints.Add(x); maxExtensionPointsLength += x.MaximumExtensionLength; minExtensionPointsLength += x.MinimumExtensionLength; } } } // fill all pending extension points while (extensionPoints.Count > 0) { int randomIndex = random.Next(extensionPoints.Count); TreeExtensionPoint nextExtension = extensionPoints[randomIndex]; extensionPoints.RemoveAt(randomIndex); ISymbolicExpressionTreeNode parent = nextExtension.Parent; int a = nextExtension.ChildIndex; ReplaceWithMinimalTree(random, root, parent, a); } return(true); }