RuinaFunction(|.|) is smooth at zero!

dune/tectonic/nicefunction.hh

@@ -68,12 +68,14 @@ class RuinaFunction : public NiceFunction {
   double virtual regularity(double x) const {
     double const arg = x / h * eta;
     // TODO: Make this controllable
-    if (arg < 1e-14 || std::abs(arg - rho) < 1e-14)
+    if (std::abs(arg - rho) < 1e-14)
       return std::numeric_limits<double>::infinity();
 
     return std::abs(second_deriv(x));
   }
 
+  bool virtual smoothesNorm() const { return true; }
+
 private:
   double const a;
   double const eta;