Hello I am using DMPlex to construct a fully circular 2D domain for my PDEs. As I am discretizing the PDEs using finite difference method, I need to know , to define the layout of PetscSection, how I can find the boundary condition IS. I know the location of the boundaries in Sieve chart. However, I noticed that I need to know the Index Set of that location. Can I use the Sieve point number for Index Set. It seems I think I am not familiar with IS. Can you help me? Thank for your help.
Amir
