Changeset 11388

Timestamp:

09/23/14 17:16:28 (10 years ago)

Author:

bburlacu

Message:

#1772: SymbolicDataAnalysisExpressionTracing: added more detailed comments; enforced a safer behaviour in the case of mutation when the traced subtree is contained inside the mutated tree fragment.

File:

• branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Tracking/SymbolicDataAnalysisExpressionTracing.cs (modified) (3 diffs)

branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Tracking/SymbolicDataAnalysisExpressionTracing.cs

@@ -64 +64 @@
 
         if (fragment == null) {
-          // fragment == null can only mean that the individual is the previous generation elite 
-          // which got introduced in the next generation. skip elite, go up the graph to original individual
+          // the fragment can be null for two reasons:
+          // 1) the individual is an elite
+          // 2) the crossover/mutation made no changes to the root parent (or there is a bug in fragment identification)
+          if (index >= parents[0].Data.Length) {
+            throw new InvalidOperationException("Index exceeds tree length.");
+          }
           node = parents[0];
           continue;
@@ -92 +96 @@
           } else if (fragment.Index1 < subtreeIndex) {
             if (subtreeIndex < fragment.Index1 + fragmentLength) {
-              // subtree contained in fragment, index stays the same
+              // in the case of mutation, the fragment could have been introduced via a node replacement
+              // there is no guarantee the subtree exists above this level, therefore the index is set to the fragment index
+              index = fragment.Index1;
             } else {
+              // subtree outside of fragment
               index += node.Data.NodeAt(fragment.Index1).GetLength() - fragmentLength;
             }
@@ -106 +113 @@
 
           yield return fragmentNode;
-          var up = Trace(node, index, fragmentNode);
+          var up = Trace(node, index, fragmentNode); // force immediate query execution
           foreach (var v in up) { yield return v; }
           break;