Changeset 7497 for branches/HeuristicLab.Crossovers/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDepthConstrainedCrossover.cs

Timestamp:

02/21/12 11:08:58 (12 years ago)

Author:

bburlacu

Message:

#1682:

• Added names and detailed descriptions to all crossover operators
• Minor code improvements (selection of allowed branches and cutpoints)

File:

• branches/HeuristicLab.Crossovers/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDepthConstrainedCrossover.cs (modified) (5 diffs)

branches/HeuristicLab.Crossovers/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDepthConstrainedCrossover.cs

@@ -32 +32 @@
 namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
 
-  [Item("DepthConstrainedCrossover", "An operator which performs subtree swapping within a specific depth range.")]
+  [Item("DepthConstrainedCrossover", "An operator which performs subtree swapping within a specific depth range. The range parameter controls the crossover behavior:\n" +
+                                     "- HighLevel (upper 25% of the tree)\n" +
+                                     "- Standard (mid 50% of the tree)\n" +
+                                     "- LowLevel (lower 25% of the tree)")]
   public sealed class SymbolicDataAnalysisExpressionDepthConstrainedCrossover<T> :
     SymbolicDataAnalysisExpressionCrossover<T> where T : class, IDataAnalysisProblemData {
@@ -60 +63 @@
       DepthRangeParameter.ValidValues.Add(new StringValue(Enum.GetName(typeof(Ranges), Ranges.Standard)).AsReadOnly());
       DepthRangeParameter.ValidValues.Add(new StringValue(Enum.GetName(typeof(Ranges), Ranges.LowLevel)).AsReadOnly());
+      Name = "DepthConstrainedCrossover";
     }
     public override IDeepCloneable Clone(Cloner cloner) { return new SymbolicDataAnalysisExpressionDepthConstrainedCrossover<T>(this, cloner); }
@@ -83 +87 @@
     /// <returns></returns>
     public static ISymbolicExpressionTree Cross(IRandom random, ISymbolicExpressionTree parent0, ISymbolicExpressionTree parent1, int maxDepth, int maxLength, string mode) {
-      int depth = parent0.Root.GetDepth() - 1; // subtract 1 because the tree levels are counted from 0 
+      int depth = parent0.Root.GetDepth() - 1; // substract 1 because the tree levels are counted from 0 
       var depthRange = new IntRange();
       const int depthOffset = 2; // skip the first 2 levels (root + startNode)
@@ -118 +122 @@
 
       var allowedBranches = (from s in GetNodesAtDepth(parent1, depthRange)
-                             where
-                               crossoverPoint0.IsMatchingPointType(s) &&
-                               s.GetDepth() + level <= maxDepth &&
-                               s.GetLength() + length <= maxLength
+                             where s.GetDepth() + level <= maxDepth
+                             where s.GetLength() + length <= maxLength
+                             where crossoverPoint0.IsMatchingPointType(s)
                              select s).ToList();
       if (allowedBranches.Count == 0) return parent0;
       var selectedBranch = allowedBranches.SelectRandom(random);
-      swap(crossoverPoint0, selectedBranch);
+      Swap(crossoverPoint0, selectedBranch);
       return parent0;
     }
@@ -136 +139 @@
              where depth <= depthRange.End
              select node;
-
-      //var list = new List<Tuple<ISymbolicExpressionTreeNode, int>> { new Tuple<ISymbolicExpressionTreeNode, int>(root, 0) };
-      //int offset = 0;
-      //int level = 0;
-      //while (level < range.End) {
-      //  ++level;
-      //  int count = list.Count;
-      //  for (int i = offset; i != count; ++i) {
-      //    if (list[i].Item1.Subtrees.Any())
-      //      list.AddRange(from s in list[i].Item1.Subtrees select new Tuple<ISymbolicExpressionTreeNode, int>(s, level));
-      //  }
-      //  offset = count;
-      //}
-      //// taking advantage of the fact that the list is already sorted by level
-      //for (int i = list.Count - 1; i >= 0; --i) {
-      //  if (list[i].Item2 >= range.Start)
-      //    yield return list[i].Item1;
-      //  else break;
-      //}
-    }
-
-    private static void swap(CutPoint crossoverPoint, ISymbolicExpressionTreeNode selectedBranch) {
-      // perform the actual swap
-      if (crossoverPoint.Child != null) {
-        // manipulate the tree of parent0 in place
-        // replace the branch in tree0 with the selected branch from tree1
-        crossoverPoint.Parent.RemoveSubtree(crossoverPoint.ChildIndex);
-        if (selectedBranch != null) {
-          crossoverPoint.Parent.InsertSubtree(crossoverPoint.ChildIndex, selectedBranch);
-        }
-      } else {
-        // child is null (additional child should be added under the parent)
-        if (selectedBranch != null) {
-          crossoverPoint.Parent.AddSubtree(selectedBranch);
-        }
-      }
     }
   }