Anders Logg wrote:
On Fri, Apr 23, 2010 at 10:44:19AM +0100, Garth N. Wells wrote:
Anders Logg wrote:
On Fri, Apr 23, 2010 at 09:34:16AM +0100, Garth N. Wells wrote:
This sounds very PETSc-speecific. Should it be a parameter of
PETScMatrix only?
Garth
Yes, perhaps. I find it a bit strange that MatZeroRows breaks for
rows without elements.
Send a PETSc bug report?
Yes, that might be the best option.
A solution would be to check the number of row entries, if possible.
I also though of that but didn't find a fast way to check it. Perhaps
I've overlooked some PETSc function that does this?
I checked the PETSc doc and the DOLFIN code and and setting the
parameter in dolfin/la/PETScMatrix.cpp
MatSetOption(*A, MAT_KEEP_ZEROED_ROWS, PETSC_TRUE);
causes to the MatZeroRowIS function not to the change the nonzero structure:
http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Mat/MatSetOption.html#MatSetOption
and
http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Mat/MatZeroRowsIS.html#MatZeroRowsIS
and seems therefore (in our case) to throw an error if you want to add a
nonzero value to a zero diagonal entry.
Just tested it here and it went fine without setting use_ident=false.
What is the reason for setting this option?
--
Andre
--
Anders
------------------------------------------------------------------------
_______________________________________________
Mailing list: https://launchpad.net/~dolfin
Post to : [email protected]
Unsubscribe : https://launchpad.net/~dolfin
More help : https://help.launchpad.net/ListHelp
_______________________________________________
Mailing list: https://launchpad.net/~dolfin
Post to : [email protected]
Unsubscribe : https://launchpad.net/~dolfin
More help : https://help.launchpad.net/ListHelp
