Hi Jed,
Revisiting this now; thanks for your help so far. I understand that I can
use PetscSFBcast() for this, but it is not clear to me whether there is a
good way that I can make use of the "default" SF that exists (or the
"default" PetscSection used to construct this). Should I just construct
some other "default" for local-to-local, or is there a good way to remap
the "global" vector layout onto a local one?
--Richard
On 6/12/13 11:25 AM, Jed Brown wrote:
Richard Tran Mills <[email protected]> writes:
PETSc developers,
I am finally getting around to adding the DMLocalToLocalBegin/End routines
that I had mentioned several months ago. Looking at
DMGlobalToLocalBegin() in src/interface/dm/dm.c, I see that a little over
a year ago, Matt added the use of a default 'PetscSF' ("star forest") if
present to handle the global-to-local and local-to-global operations. I
am not familiar with PetscSF, but I assume that it should be possible to
use these somehow (maybe needing to add a little bit of code) for
local-to-local operations, since the communication pattern is the same as
for a global-to-local. Could someone who is familiar with PetscSF comment
on this?
You can use PetscSFBcast for this. For each point (which will be a leaf
in star-forest terminology), set the (rank, offset) of the owner
("root"). Use PetscSFSetGraph rather than PetscSFSetGraphLayout,
because you don't have a global ordering/PetscLayout to use the latter.
--
Richard Tran Mills, Ph.D.
Computational Earth Scientist | Joint Assistant Professor
Hydrogeochemical Dynamics Team | EECS and Earth & Planetary Sciences
Oak Ridge National Laboratory | University of Tennessee, Knoxville
E-mail: [email protected] V: 865-241-3198 http://climate.ornl.gov/~rmills
