[ScaledIDMatrix]

use FieldTraits to determin the return type of the norm methods

dune/istl/scaledidmatrix.hh

@@ -16,6 +16,7 @@
 #include <dune/common/exceptions.hh>
 #include <dune/common/fmatrix.hh>
 #include <dune/common/diagonalmatrix.hh>
+#include <dune/common/ftraits.hh>
 
 namespace Dune {
 
@@ -344,25 +345,25 @@ namespace Dune {
     //===== norms
 
     //! frobenius norm: sqrt(sum over squared values of entries)
-    double frobenius_norm () const
+    typename FieldTraits<field_type>::real_type frobenius_norm () const
     {
       return fvmeta::sqrt(n*p_*p_);
     }
 
     //! square of frobenius norm, need for block recursion
-    double frobenius_norm2 () const
+    typename FieldTraits<field_type>::real_type frobenius_norm2 () const
     {
       return n*p_*p_;
     }
 
     //! infinity norm (row sum norm, how to generalize for blocks?)
-    double infinity_norm () const
+    typename FieldTraits<field_type>::real_type infinity_norm () const
     {
       return std::abs(p_);
     }
 
     //! simplified infinity norm (uses Manhattan norm for complex values)
-    double infinity_norm_real () const
+    typename FieldTraits<field_type>::real_type infinity_norm_real () const
     {
       return fvmeta::absreal(p_);
     }