Changeset 7075 for branches/gp-crossover/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover.cs

Timestamp:

11/25/11 11:41:48 (12 years ago)

Author:

bburlacu

Message:

#1682: Updated crossovers

File:

• branches/gp-crossover/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover.cs (modified) (5 diffs)

branches/gp-crossover/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover.cs

@@ -37 +37 @@
     [StorableConstructor]
     private SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover(bool deserializing) : base(deserializing) { }
-    private SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover(SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover<T> original, Cloner cloner)
-      : base(original, cloner) {
-    }
-    public SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover()
-      : base() {
-    }
-    public override IDeepCloneable Clone(Cloner cloner) {
-      return new SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover<T>(this, cloner);
-    } 
+    private SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover(SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover<T> original, Cloner cloner) 
+      : base(original, cloner) { }
+    public SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover() : base() { }
+    public override IDeepCloneable Clone(Cloner cloner) { return new SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover<T>(this, cloner); }
+ 
     protected override ISymbolicExpressionTree Cross(IRandom random, ISymbolicExpressionTree parent0, ISymbolicExpressionTree parent1) {
       ISymbolicDataAnalysisExpressionTreeInterpreter interpreter = SymbolicDataAnalysisTreeInterpreterParameter.ActualValue;
       IEnumerable<int> rows = GenerateRowsToEvaluate();
       T problemData = ProblemDataParameter.ActualValue;
-      return Cross(random, parent0, parent1, interpreter, problemData, rows, MaximumSymbolicExpressionTreeDepth.Value, MaximumSymbolicExpressionTreeLength.Value);
+      var grammar = parent0.Root.Grammar;
+      return Cross(random, parent0, parent1, interpreter, problemData, 
+                   rows, MaximumSymbolicExpressionTreeDepth.Value, MaximumSymbolicExpressionTreeLength.Value);
     }
 
@@ -60 +58 @@
     /// choose the second crosspoint via a random weighted selection procedure.
     /// </summary>
-    public static ISymbolicExpressionTree Cross(IRandom random, ISymbolicExpressionTree parent0, ISymbolicExpressionTree parent1,
+    public static ISymbolicExpressionTree Cross(IRandom random, ISymbolicExpressionTree parent0, ISymbolicExpressionTree parent1, 
                                                 ISymbolicDataAnalysisExpressionTreeInterpreter interpreter, T problemData, IEnumerable<int> rows, int maxDepth, int maxLength) {
       List<CutPoint> crossoverPoints0 = new List<CutPoint>();
@@ -89 +87 @@
 
       // create symbols in order to improvize an ad-hoc tree so that the child can be evaluated
-      var rootSymbol = new ProgramRootSymbol();
-      var startSymbol = new StartSymbol();
-      var tree0 = CreateTreeFromNode(random, crossoverPoint0.Child, rootSymbol, startSymbol);
+      var tree0 = CreateTreeFromNode(random, crossoverPoint0.Child, (ISymbolicExpressionGrammar)parent0.Root.Grammar);
       IEnumerable<double> estimatedValues0 = interpreter.GetSymbolicExpressionTreeValues(tree0, dataset, rows);
       double min0 = estimatedValues0.Min();
@@ -98 +94 @@
       List<double> weights = new List<double>();
       foreach (var node in allowedBranches) {
-        var tree1 = CreateTreeFromNode(random, node, rootSymbol, startSymbol);
+        var tree1 = CreateTreeFromNode(random, node, (ISymbolicExpressionGrammar)parent0.Root.Grammar);
         IEnumerable<double> estimatedValues1 = interpreter.GetSymbolicExpressionTreeValues(tree1, dataset, rows);
         double min1 = estimatedValues1.Min();
@@ -109 +105 @@
 
       ISymbolicExpressionTreeNode selectedBranch = SelectRandomBranch(random, allowedBranches, weights);
+      swap(crossoverPoint0, selectedBranch);
 
-      // perform the actual swap
-      if (crossoverPoint0.Child != null) {
+      return parent0;
+    }
+
+    private static void swap(CutPoint crossoverPoint, ISymbolicExpressionTreeNode selectedBranch) {
+      if (crossoverPoint.Child != null) {
         // manipulate the tree of parent0 in place
         // replace the branch in tree0 with the selected branch from tree1
-        crossoverPoint0.Parent.RemoveSubtree(crossoverPoint0.ChildIndex);
+        crossoverPoint.Parent.RemoveSubtree(crossoverPoint.ChildIndex);
         if (selectedBranch != null) {
-          crossoverPoint0.Parent.InsertSubtree(crossoverPoint0.ChildIndex, selectedBranch);
+          crossoverPoint.Parent.InsertSubtree(crossoverPoint.ChildIndex, selectedBranch);
         }
       } else {
         // child is null (additional child should be added under the parent)
         if (selectedBranch != null) {
-          crossoverPoint0.Parent.AddSubtree(selectedBranch);
+          crossoverPoint.Parent.AddSubtree(selectedBranch);
         }
       }
-
-      return parent0;
     }