Hi Matt,
One further question on this. I am working on the code now, but have one
issue.
The IS I grab from all fields need to be set to the sub PCs, but they
will have a local ordering of the dofs. Is there a tool in PETSc to make
this coherent? I.e. if I will set the IS fields '0,4,7' to a a subPC
object within the Fieldsplit structure, how to build a new PC such that
setting
PCSetFieldIS(pc, '0', field[0])
PCSetFieldIS(pc, '1', field[4])
PCSetFieldIS(pc, '2', field[7])
makes sense in the new subPC?
Thanks for the help.
Best,
NB
On 22-02-23 14:54, Nicolas Barnafi wrote:
Hi Matt,
Sorry for the late answer, it was holiday time.
Just to clarify, if you call SetIS() 3 times, and then give
-pc_fieldsplit_0_fields 0,2
then we should reduce the number of fields to two by calling
ISConcatenate() on the first and last ISes?
Exactly
I think this should not be hard. It will work exactly as it does on
the DM case, except the ISes will come from
the PC, not the DM. One complication is that you will have to hold the
new ISes until the end, and then set them.
Thanks,
Matt
Nice, then it is exactly what I want. I will work on it, and create a PR
when things are starting to fit in.
Best,
NB
