Changeset 12347

Timestamp:

04/25/15 00:53:07 (9 years ago)

Author:

bburlacu

Message:

#2320: Bugfix to allow nodes that can appear both internally or as leafs

File:

• branches/SymbolicExpressionTreeEncoding/HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.4/Creators/GrowTreeCreator.cs (modified) (3 diffs)

branches/SymbolicExpressionTreeEncoding/HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.4/Creators/GrowTreeCreator.cs

@@ -89 +89 @@
         throw new ArgumentException("Cannot grow tree. Seed node shouldn't have arity zero.");
 
-      var allowedSymbols = seedNode.Grammar.AllowedSymbols
-        .Where(s => s.InitialFrequency > 0.0)
-        .ToList();
+      var allowedSymbols = seedNode.Grammar.AllowedSymbols.Where(s => s.InitialFrequency > 0.0).ToList();
 
       for (var i = 0; i < arity; i++) {
-        var possibleSymbols = allowedSymbols
-          .Where(s => seedNode.Grammar.IsAllowedChildSymbol(seedNode.Symbol, s, i))
-          .ToList();
+        var possibleSymbols = allowedSymbols.Where(s => seedNode.Grammar.IsAllowedChildSymbol(seedNode.Symbol, s, i)).ToList();
         var weights = possibleSymbols.Select(s => s.InitialFrequency).ToList();
         var selectedSymbol = possibleSymbols.SelectRandom(weights, random);
@@ -113 +109 @@
     private static void RecursiveCreate(IRandom random, ISymbolicExpressionTreeNode root, int currentDepth, int maxDepth) {
       var arity = SampleArity(random, root);
-      if (arity <= 0)
-        throw new ArgumentException("Cannot grow node of arity zero. Expected a function node.");
+      if (arity == 0)
+        return;
 
       var allowedSymbols = root.Grammar.AllowedSymbols.Where(s => s.InitialFrequency > 0.0).ToList();
 
       for (var i = 0; i < arity; i++) {
-        var possibleSymbols = allowedSymbols
-          .Where(s => root.Grammar.IsAllowedChildSymbol(root.Symbol, s, i) &&
-            root.Grammar.GetMinimumExpressionDepth(s) - 1 <= maxDepth - currentDepth)
-          .ToList();
+        var possibleSymbols = allowedSymbols.Where(s => root.Grammar.IsAllowedChildSymbol(root.Symbol, s, i) &&
+                                                        root.Grammar.GetMinimumExpressionDepth(s) - 1 <= maxDepth - currentDepth).ToList();
 
         if (!possibleSymbols.Any())
           throw new InvalidOperationException("No symbols are available for the tree.");
+
         var weights = possibleSymbols.Select(s => s.InitialFrequency).ToList();
         var selectedSymbol = possibleSymbols.SelectRandom(weights, random);
@@ -133 +128 @@
       }
 
-      foreach (var subTree in root.Subtrees)
-        if (subTree.Grammar.GetMaximumSubtreeCount(subTree.Symbol) != 0)
-          RecursiveCreate(random, subTree, currentDepth + 1, maxDepth);
+      if (maxDepth > currentDepth)
+        foreach (var subTree in root.Subtrees)
+          if (subTree.Grammar.GetMaximumSubtreeCount(subTree.Symbol) != 0)
+            RecursiveCreate(random, subTree, currentDepth + 1, maxDepth);
     }