Hi community,

This is more of a theoretical concern. Regarding vector elements which have dofs on th normal components (RT, BDM), typical boundary conditions are of type

u.n = f

i.e, something on the normal component. Now, implementations all around fenics are done by imposing something on the entire vector, such as

DirichletBC(V.sub(u_component), Constant((1,2,3)), “on_boundary”),

where I’m assuming that u is a vector. So my question is, does this assign only the corresponding dof, meaning that if u_D=(1,2,3), in this case I would get

u.n = (1,2,3).n

or does it set dofs somehow differently? Thanks for your help, and sorry but I couldn’t find anything related on the documentation.

Best regards

Pd: The same would apply to curl elements w.r.t curl boundary conditions.