Hi,
I have a multi physics application with discipline1 defined on comm1 and
discipline2 on comm2.
My intent is to use the nested matrix for the KSP solver where each
diagonal block is provided by the disciplines, and the off-diagonal blocks are
defined as shell-matrices with matrix vector products.
I am a bit unclear about how to deal with the case of different set of
processors on comm1 and comm2. I have the following questions and would
appreciate some guidance:
— Would it make sense to define a comm_global as a union of comm1 and comm2 for
the MatCreateNest?
— The diagonal blocks are available on comm1 and comm2 only. Should
MatAssemblyBegin/End for these diagonal blocks be called on comm1 and comm2
separately?
— What comm should be used for the off-diagonal shell matrices?
— Likewise, when calling VecGetSubVector and VecRestoreSubVector to get
sub-vectors corresponding to discipline1 (or 2), what comm should these
function calls be made?
Thanks,
Manav
