Changeset 14883 for branches/RBFRegression/HeuristicLab.Algorithms.DataAnalysis/3.4/RadialBasisFunctions/KernelFunctions/InverseMultiquadraticKernel.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/InverseMultiquadraticKernel.cs (modified) (2 diffs)

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

@@ -46 +46 @@
 
     protected override double Get(double norm) {
-      if (Math.Abs(Beta) < double.Epsilon) return 0;
+      if (Math.Abs(Beta) < double.Epsilon) return double.NaN;
       return 1 / Math.Sqrt(1 + norm * norm / Beta);
     }
@@ -52 +52 @@
     protected override double GetGradient(double norm) {
       if (Math.Abs(Beta) < double.Epsilon) return double.NaN;
-      norm *= norm;
-      return norm / (2 * Beta * Beta * Math.Pow((norm + Beta) / Beta, 1.5));
+      return norm * norm / (2 * Beta * Beta * Math.Pow((norm * norm + Beta) / Beta, 1.5));
     }
   }