[petsc-users] Index set with zero size

[Tim Kroeger]

On Thu, 11 Nov 2010, Tim Kroeger wrote:

> On Wed, 10 Nov 2010, Jed Brown wrote:
>
>> On Tue, Nov 9, 2010 at 15:43, Tim Kroeger <tim.kroeger at cevis.uni-bremen.de> 
>> wrote:
>>       Okay, I implemented a workaround on user side (using a temporary 
>> vector and MatMult()).  This seems to
>>       resolve the problem now.  I'll leave it like this in the libMesh 
>> part, so that libMesh remains
>>       compatible with PETSc-3.1-p4.  Nevertheless, if you fix this within a 
>> few days and launch PETSc-3.1-p5
>>       with this fix (or just send me a patch), let me know, I can then test 
>> it.
>> 
>> 
>> I fixed this, and also a bug with nontrivial MatDiagonalScale after 
>> MatGetSubMatrix.  You can get it from hg, or in
>> the next patch level (I don't know when that will be).
>
> Yes, this fixes it.  Thank you very much again.

One more question: Does this bux and fix also apply to a submatrix of 
an MPIAIJ matrix? That is, can I safely use MatMultAdd() having v2==v3 
for such a matrix in 3.1.0-p4 or not?  (I'm having trouble with such a 
matrix now, but the error might be on my side.)

Best Regards,

Tim

-- 
Dr. Tim Kroeger
CeVis -- Center of Complex Systems and Visualization
University of Bremen              tim.kroeger at cevis.uni-bremen.de
Universitaetsallee 29             tim.kroeger at mevis.fraunhofer.de
D-28359 Bremen                             Phone +49-421-218-7710
Germany                                    Fax   +49-421-218-4236