Dear Wolfgang, Thanks for a quick reply, and sorry for ambiguity. To be more precise (trying to be) I should say the lines I modified with the aim of creating a so-called "view" do not do that for my intended variable. My question mainly was that if using the [ ] operator (that I added) does the job of identifying the desired field on the faces? Is the usage correct? I am also a bit confused as fe.system_to_component_index <https://www.dealii.org/current/doxygen/deal.II/classFiniteElement.html#a86644fe67824373cd51e9ff7fca94f8c>(i) seems to do the same but not for the faces I guess. So not sure which approach should be taken.
Thank you, Ali On Mon, Jan 31, 2022 at 6:29 PM Wolfgang Bangerth <bange...@colostate.edu> wrote: > On 1/31/22 10:22, Ali Seddiq wrote: > > > > I am trying to mimic step-7 implementation of Neumann boundary condition > in > > the case of a vector-valued problem. > > I did some modifications as shown in the below, but it doesn't work as > expected; > > > > const FEValuesExtractors::Scalar pressure(0); > > > > ..... > > cell_rhs(i) += > > (fe_face_values[pressure].value(i, q_point) * > > neumann_value * > > fe_face_values.JxW(q_point)); > > > > I tried to replicate step-20 and related documentation on vector > problems but > > haven't yet been able to figure out the solution. > > So any help is much appreciated. > > Ali -- a good place to always start is by asking what "it doesn't work as > expected" precisely is. We don't know what the problem is you are trying > to > solve, we don't know whether you get compiler errors, whether you get > runtime > errors, whether the solution looks wrong, in which way it looks wrong, etc. > > Debugging typically starts with asking *yourself* precisely what doesn't > work, > and what that might mean for where the bug is. > > Best > W. > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: bange...@colostate.edu > www: http://www.math.colostate.edu/~bangerth/ > > -- > The deal.II project is located at http://www.dealii.org/ > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > --- > You received this message because you are subscribed to the Google Groups > "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to dealii+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/dealii/01451b66-7c40-3eb3-53c3-3024eaaad3db%40colostate.edu > . > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/CAGCqmDqk2kqHNHnpaJpfiJHURxLdo3p4bodOfy5JC7VHcRrz8w%40mail.gmail.com.
