Dear all,
We are building out a new finite-element code for wave propagation and I
am currently implementing the boundary conditions. My first pass will
simply have dirichlet boundaries, but eventually we will have more
sophisticated options available.
I am creating an exodus mesh in Trelis/Cubit, in which I can create one
(or more) "side sets", which are properly read by the exodus reader.
From reading the petsc source (plexexodusii.c), it seems that these
basically create a list of faces, which belong to the side set.
A call to DMPlexGetLabelValue(dm,"Face Set",face_id,&value), allows me
to see if "face_id" is on the boundary by checking value (>=1 for
boundary, or -1 for not in set). Additional side sets get ids =
{2,3,etc}. This allows us to have multiple types of boundary (absorbing,
reflecting, etc).
However, I am unsure how to determine if an element has a particular
face_id in order to determine if one face of the element is on a
boundary (and which value it has {-1,1,2,3, etc}).
The routine is listed here:
PetscErrorCode DMPlexGetLabelValue(DM dm, const char name[],
PetscInt point, PetscInt *value)
How do I determine the "point" of a face, if I'm iterating through my
elements.
thanks!
Max Rietmann
PS I've also seen the DMPlexAddBoundary method, but I wasn't sure how to
use it in our setting.
