if you want to use a general unstructured grid, you may want to have a look at $PETSC_DIR/src/dm/ao/examples/tutorials/ex2.c Mohammad On Thu, Aug 4, 2011 at 4:43 PM, Matthew Knepley <[email protected]> wrote:
On Thu, Aug 4, 2011 at 11:31 PM, Tabrez Ali <[email protected]>wrote:
Hello
If a mesh is partitioned using Metis but the original order of nodes is used to create/partition the matrix then would this be significantly bad for performance and scalability.
That depends. Many mesh generators h ave fairly good ordering on output, but some do not. Definitely a bad order can make a huge difference in performance, both for cache traffic and conditioning reasons.
Also is there an example that uses Metis to partition an unstructured mesh?
This depends on what you mean. If you can encode your mesh as a Mat, you can use MatPartitoning. If not, you would need to use DMMesh things, such as SNES ex12.
Matt
Thanks in advance.
Tabrez
-- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener