Dear PETSc Team:
Hi! I'm working on a parallel version of a PETSc script that I wrote in serial
using DMPlex. After calling DMPlexDistribute() each rank is assigned its own
DAG where the points are numbered locally. For example, If I split a 100-cell
mesh over 4 processors, each process numbers their cells 0-24 as oppossed to
something like 0-24, 25-49, 50-74, and 74-99 on ranks 0,1,2, and 3
respectively. The same happens for Face, Edge, and Vertex points in that the
local DAG's renumber the ID's starting with 0 instead of using global numbering.
How can I distribute a mesh such that the global numbering is reflected in the
local DAG's? If not, what would be the right way to retrieve the global
numbering? I've seen the term "StarForest" in some [petsc-users] discussion
threads discussing a similar issue but have little clue as how to use them.
I've looked at the following functions:
* DMPlexCreatePointNumbering() - Sounds like what I need, but I don't think
it will work because I am relying on DMPlexGetDepthStratum() which returns
bounds in local numbering.
* DMPlexGetCellNumbering() - Only converts Cells
* DMPlexGetVertexNumbering() - Only converts Vertices
Basically, what I want to do is to have a global matrix and have my MPI ranks
call MatSetValues() on it (with ADD_VALUES as the mode). In my serial code I
was relying on the global point numbering to build the matrix. Without it, I
can't do it my way : (. I'm manually assembling a global stiffness matrix out
of element stiffness matrices to run FEA.
Any help is much appreciated.
Sincerely:
J.A. Ferrand
Embry-Riddle Aeronautical University - Daytona Beach FL
M.Sc. Aerospace Engineering | May 2022
B.Sc. Aerospace Engineering
B.Sc. Computational Mathematics
Sigma Gamma Tau
Tau Beta Pi
Honors Program
Phone: (386)-843-1829
Email(s): ferra...@my.erau.edu
jesus.ferr...@gmail.com
