Use Arithmetic

dune/tectonic/minimisation.hh

@@ -5,6 +5,7 @@
 #include <dune/common/fvector.hh>
 #include <dune/common/stdstreams.hh>
 
+#include <dune/fufem/arithmetic.hh>
 #include <dune/fufem/interval.hh>
 #include <dune/solvers/computeenergy.hh>
 #include <dune/tnnmg/problem-classes/bisection.hh>
@@ -28,9 +29,9 @@ void descentMinimisation(Functional const &J,
 
      since A is symmetric.
   */
-  SmallVector tmp = J.b;         //  b
-  J.A.mmv(x, tmp);               //  b-Au
-  double const JRestb = tmp * v; // <b-Au,v>
+  SmallVector tmp = J.b;
+  Arithmetic::addProduct(tmp, -1.0, J.A, x);
+  double const JRestb = tmp * v;
 
   MyDirectionalConvexFunction<LocalNonlinearityType> const JRest(
       2.0 * computeEnergy(J.A, v), JRestb, *J.phi, x, v);