Changeset 618

Timestamp:

10/02/08 01:13:35 (16 years ago)

Author:

gkronber

Message:

• improved SizeFairCrossOver
• implemented very simple and strict form of a homologous crossover operator

(ticket #108)

Location:

trunk/sources/HeuristicLab.StructureIdentification

Files:

• HeuristicLab.StructureIdentification.csproj (modified) (1 diff)
• Recombination/OnePointCrossOver.cs (added)
• Recombination/SizeFairCrossOver.cs (modified) (5 diffs)

trunk/sources/HeuristicLab.StructureIdentification/HeuristicLab.StructureIdentification.csproj

@@ -101 +101 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="RampedTreeCreator.cs" />
+    <Compile Include="Recombination\OnePointCrossOver.cs" />
     <Compile Include="Recombination\StandardCrossOver.cs" />
     <Compile Include="Recombination\SizeFairCrossOver.cs" />

trunk/sources/HeuristicLab.StructureIdentification/Recombination/SizeFairCrossOver.cs

@@ -126 +126 @@
         }
 
-        // save the roots because later on we change tree0 and tree1 while searching a valid tree configuration
-        IFunctionTree root0 = tree0;
-        IFunctionTree root1 = tree1;
-        int root0Height = tree0Height;
-        int root1Height = tree1Height;
-        int rootSize = tree0Size;
-
         // select a random suboperator of the 'receiving' tree
-        IFunctionTree crossoverPoint = gardener.GetRandomParentNode(root0);
+        IFunctionTree crossoverPoint = gardener.GetRandomParentNode(tree0);
         int removedBranchIndex;
         IFunctionTree removedBranch;
@@ -140 +133 @@
         if(crossoverPoint == null) {
           removedBranchIndex = 0;
-          removedBranch = root0;
+          removedBranch = tree0;
           allowedFunctions = gardener.GetAllowedSubFunctions(null, 0);
         } else {
@@ -148 +141 @@
         }
         int removedBranchSize = removedBranch.Size;
-        int maxBranchSize = maxTreeSize - (root0.Size - removedBranchSize);
-        int maxBranchHeight = maxTreeHeight - gardener.GetBranchLevel(root0, removedBranch);
-        IFunctionTree insertedBranch = GetReplacementBranch(random, gardener, allowedFunctions, root1, removedBranchSize, maxBranchSize, maxBranchHeight);
+        int maxBranchSize = maxTreeSize - (tree0.Size - removedBranchSize);
+        int maxBranchHeight = maxTreeHeight - gardener.GetBranchLevel(tree0, removedBranch);
+        IFunctionTree insertedBranch = GetReplacementBranch(random, gardener, allowedFunctions, tree1, removedBranchSize, maxBranchSize, maxBranchHeight);
 
         int tries = 0;
         while(insertedBranch == null) {
           if(tries++ > MAX_RECOMBINATION_TRIES) {
-            if(random.Next() > 0.5) return root1;
-            else return root0;
+            if(random.Next() > 0.5) return tree1;
+            else return tree0;
           }
 
           // retry with a different crossoverPoint        
-          crossoverPoint = gardener.GetRandomParentNode(root0);
+          crossoverPoint = gardener.GetRandomParentNode(tree0);
           if(crossoverPoint == null) {
             removedBranchIndex = 0;
-            removedBranch = root0;
+            removedBranch = tree0;
             allowedFunctions = gardener.GetAllowedSubFunctions(null, 0);
           } else {
@@ -171 +164 @@
           }
           removedBranchSize = removedBranch.Size;
-          maxBranchSize = maxTreeSize - (root0.Size - removedBranchSize);
-          maxBranchHeight = maxTreeHeight - gardener.GetBranchLevel(root0, removedBranch) + 1;
-          insertedBranch = GetReplacementBranch(random, gardener, allowedFunctions, root1, removedBranchSize, maxBranchSize, maxBranchHeight);
+          maxBranchSize = maxTreeSize - (tree0.Size - removedBranchSize);
+          maxBranchHeight = maxTreeHeight - gardener.GetBranchLevel(tree0, removedBranch) + 1;
+          insertedBranch = GetReplacementBranch(random, gardener, allowedFunctions, tree1, removedBranchSize, maxBranchSize, maxBranchHeight);
         }
         if(crossoverPoint != null) {
@@ -179 +172 @@
           crossoverPoint.RemoveSubTree(removedBranchIndex);
           crossoverPoint.InsertSubTree(removedBranchIndex, insertedBranch);
-          return root0;
+          return tree0;
         } else {
           return insertedBranch;