Changeset 4126

Timestamp:

08/01/10 18:11:15 (14 years ago)

Author:

gkronber

Message:

Added check in correlation coefficient calculation to prevent division by zero. #1116

File:

• trunk/sources/HeuristicLab.Problems.DataAnalysis/3.3/Evaluators/OnlinePearsonsRSquaredEvaluator.cs (modified) (1 diff)

trunk/sources/HeuristicLab.Problems.DataAnalysis/3.3/Evaluators/OnlinePearsonsRSquaredEvaluator.cs

@@ -31 +31 @@
     public double RSquared {
       get {
-        double r = covEvaluator.Covariance / (Math.Sqrt(sxEvaluator.PopulationVariance) * Math.Sqrt(syEvaluator.PopulationVariance));
-        return r * r;
+        double xVar = sxEvaluator.PopulationVariance;
+        double yVar = syEvaluator.PopulationVariance;
+        if (xVar.IsAlmost(0.0) || yVar.IsAlmost(0.0)) {
+          return 0.0;
+        } else {
+          double r = covEvaluator.Covariance / (Math.Sqrt(xVar) * Math.Sqrt(yVar));
+          return r * r;
+        }
       }
     }