[petsc-users] Bug when multipling a SBAIJ matrix with a vector

[Jed Brown]

On Thu, Oct 21, 2010 at 14:41, Andreas Hauffe
<andreas.hauffe at tu-dresden.de> wrote:
> I get no error and this example delivers the right result for PETSC 3.0. What
> did change from 3.0 to 3.1?

Many of the matrix kernels were optimized, this one was changed in
relatively simple ways, but the data structures for factorization were
changed completely.  In this case, Barry's name is on the commit
message

http://petsc.cs.iit.edu/petsc/petsc-dev/rev/0308bd570415#l2.33

He should have put that behavioral change in the 3.1 changelog.  Or
maybe the cost of handling empty rows is actually not significant so
it should still be supported.  I can't tell from the commit message,
but empty rows are still supported by the code in MatMult_SeqSBAIJ_2,
so it probably should work for block size 1 as well.

Do you really not get an error message when you run your example code
with 3.1 built with debug support?  I just ran your code with 3.1 and
I get a (bad) error message.

Jed