On 12/5/22 07:21, Abbas wrote:
Prof. Bangerth, I probably wasn't clear in my question. I know how to apply
BCs for an interior penalty problem weakly.
But, for a non-linear problem like step 15, one initialises the solution
vector and sets it to the value of the BCs at the boundary before solving for
the Newton update. This is done explicitly in function 'set_boundary_values()'
in step 15 with the function 'VectorTools::interpolate_boundary_values
<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.dealii.org%2Fcurrent%2Fdoxygen%2Fdeal.II%2FnamespaceVectorTools.html%23ab2562d41bb26f362043f9719a8cd9b87&data=05%7C01%7CWolfgang.Bangerth%40colostate.edu%7C3d130cff49424b5b1e5008dad6cc0aa8%7Cafb58802ff7a4bb1ab21367ff2ecfc8b%7C0%7C0%7C638058469105415682%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=Avsnwwx%2BjZMnFN4YA4kxBNYU5GRIdzvd8lcRfxBVdrM%3D&reserved=0>'.
I cannot use this function with DG elements apparently and I am wondering if
there are any alternatives.
I see now. In that case, like Timo Heister said, the boundary conditions are
part of the weak form of the problem. The weak form is the residual that gives
you the right hand side of the Newton steps, and the derivative of the
residual gives you the Newton matrix. This is definitely the way to go.
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/26bc765c-ba0d-11b6-d0de-1669e375335c%40colostate.edu.
