#include "petscpc.h" PetscErrorCode PCSPAISetSp(PC pc,int sp)
|pc||- the preconditioner|
|n||- 0 or 1|
Notes: If A has a symmetric nonzero pattern use -sp 1 to improve performance by eliminating some communication in the parallel version. Even if A does not have a symmetric nonzero pattern -sp 1 may well lead to good results, but the code will not follow the published SPAI algorithm exactly.