[petsc-users] SBAIJ: Distribution of rows

[Florian Lindner]

Hello,

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.

Is that correct?

I'm not trying to change / balance that, just to confirm it. ;-)

Thanks,
Florian