[petsc-users] SBAIJ: Distribution of rows

Hong hzhang at mcs.anl.gov
Mon Apr 27 09:54:18 CDT 2015

> just to make sure I don't get something wrong:
> An SBAIJ (especially MPISBAIJ) matrix just stores the uper triangle. When
> I invoke MatSetSizes with the global dimension set (and local to
> PETSC_DECIDE) petsc tries to evenly distribute rows amoung ranks. Same when
> I set local dimensions to the same on every processor.

> This leads to unbalanced behavior regarding the number of stored elements
> on each rank. The first row (on the first rank) is completely stored, the
> last row (on the last rank) contains just one element.

Not necessarily, e.g., for a sparse banded matrix, this distribution is
well-balanced. User can set their own distribution by input local rows and
set global rows as PETSC_DECIDE.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20150427/7743b053/attachment.html>

More information about the petsc-users mailing list