> On 19 Dec 2018, at 9:46 AM, Stefano Zampini <stefano.zamp...@gmail.com> wrote:
> 
> Pierre, 
> 
> The details of the  inner solvers for PCFIELDSPLIT are not known if you don’t 
> call PCSetUp, so the cascade approach should be preferred.

OK, great! It was actually not that big of a deal to implement.

Thanks,
Pierre

> After PCSetUp, you can access the inner solves, see e.g.  
> https://bitbucket.org/petsc/petsc/src/4ddd364d454d7bce974e92e0b5bd4f4516dbff02/src/ksp/pc/impls/bddc/bddc.c#lines-2715
>> On Dec 19, 2018, at 9:01 AM, Pierre Jolivet via petsc-dev 
>> <petsc-dev@mcs.anl.gov> wrote:
>> 
>> Hello,
>> I have a PCFIELDSPLIT where the fields are defined by a MATNEST 
>> “decomposition”.
>> Right now, I am first defining the KSP of the diagonal blocks of the 
>> MATNEST, which are themselves PCFIELDSPLIT, then creating the Mat itself, 
>> and eventually I’d like to solve systems with the complete MATNEST.
>> However, the KSP and PC options of the “first level" inner solvers are not 
>> propagated to the global outer solver.
>> Can this be achieved somehow, or do I always need to set the options in the 
>> opposite direction (first outer solver, then inner solvers, e.g., through a 
>> cascade of PCFieldSplitGetSubKSP)?
>> 
>> Thanks in advance,
>> Pierre
> 

Reply via email to