Changeset 16629

Timestamp:

02/28/19 14:02:15 (6 years ago)

Author:

gkronber

Message:

#2966: added extra checks to make sure that IntervalInterpreter always returns a valid interval

File:

• trunk/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/IntervalInterpreter.cs (modified) (2 diffs)

trunk/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/IntervalInterpreter.cs

@@ -88 +88 @@
       var outputInterval = Evaluate(instructions, ref instructionCount);
 
-      return outputInterval;
+      // because of numerical errors the bounds might be incorrect
+      if (outputInterval.LowerBound <= outputInterval.UpperBound)
+        return outputInterval;
+      else
+        return new Interval(outputInterval.UpperBound, outputInterval.LowerBound);
     }
 
@@ -102 +106 @@
       var outputInterval = Evaluate(instructions, ref instructionCount, intervals);
 
-      nodeIntervals = intervals;
-
-      return outputInterval;
+      // fix incorrect intervals if necessary (could occur because of numerical errors)
+      nodeIntervals = new Dictionary<ISymbolicExpressionTreeNode, Interval>();
+      foreach(var kvp in intervals) {
+        var interval = kvp.Value;
+        if (interval.IsInfiniteOrUndefined || interval.LowerBound <= interval.UpperBound)
+          nodeIntervals.Add(kvp.Key, interval);
+        else
+          nodeIntervals.Add(kvp.Key, new Interval(interval.UpperBound, interval.LowerBound));
+      }
+
+      // because of numerical errors the bounds might be incorrect
+      if (outputInterval.IsInfiniteOrUndefined || outputInterval.LowerBound <= outputInterval.UpperBound)
+        return outputInterval;
+      else
+        return new Interval(outputInterval.UpperBound, outputInterval.LowerBound);
     }