How to form a block matrix of type petScMatrix !

Question

Hello

To point you Fenics users right on the problem,
I want to solve nonlinear Navier-Stokes equations using Newton Rapshon and gmres solver.

I have my FE matrices already assembled in Petsc type for the linear terms .

Now the question is : how can I gather these matrices to form a saddle point problem where the large matrix still of the same type (Petsc)?

Any help would be appreciated.

Answer 1

Hi,

consider the CBC.block app which can be used on top of dolfin. I think this package contains some interesting features, serving your purpose.