Changeset 14883 for branches/RBFRegression/HeuristicLab.Algorithms.DataAnalysis/3.4/RadialBasisFunctions/KernelFunctions/CicularKernel.cs

Timestamp:

04/24/17 13:17:43 (7 years ago)

Author:

bwerth

Message:

#2699 checked and reformulated gradient functions for kernels

File:

• branches/RBFRegression/HeuristicLab.Algorithms.DataAnalysis/3.4/RadialBasisFunctions/KernelFunctions/CicularKernel.cs (modified) (2 diffs)

branches/RBFRegression/HeuristicLab.Algorithms.DataAnalysis/3.4/RadialBasisFunctions/KernelFunctions/CicularKernel.cs

@@ -47 +47 @@
 
     protected override double Get(double norm) {
-      if (norm >= Beta || Math.Abs(Beta) < double.Epsilon) return 0;
+      if (Math.Abs(Beta) < double.Epsilon) return double.NaN;
+      if (norm >= Beta) return 0;
       var d = norm / Beta;
       return Math.Acos(-d) - d * Math.Sqrt(1 - d * d) - Math.PI / 2;
@@ -53 +54 @@
 
     protected override double GetGradient(double norm) {
-      if (Beta <= 0) return double.NaN;
+      if (Math.Abs(Beta) < double.Epsilon) return double.NaN;
       if (Beta < norm) return 0;
-      return 2 * norm * Math.Sqrt(Beta * Beta - norm * norm) / (Beta * Beta * Beta);
+      return -2*Math.Pow(norm,3)/(Math.Pow(Beta,4)*Math.Sqrt(1-norm*norm/(Beta*Beta)));
     }
   }