On 10/16/2017 08:55 AM, Mark Ma wrote:
> So when you visualize the solution, the error is at the boundary
but it looks
> correct in the interior?
>
> Yes, it is. Thereafter, the error at boundaries does propagate and then
> interfere with the interior.
From the pictures you posted in a follow-up, it looks like the boundary
values are actually correct, but that the problem starts one layer of cells
into the domain. Do I see this correctly?
Yes, exactly. And if I use the BC values as 0, then it seems OK now (see figs
below). What if I want to apply some value other than 0, this problem seems
annoying.
Yes, bugs are highly annoying indeed :-)
It almost looks to me like you're applying both Dirichlet values (via the
ConstraintMatrix) and Neumann boundary values (via a boundary integral). But
then I haven't taken a look at the code, so I can't really say for sure.
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.
For more options, visit https://groups.google.com/d/optout.