PCSPAISetSp#

specify a symmetric matrix sparsity pattern in the PCSPAI preconditioner

Synopsis#

#include "petscpc.h" 
PetscErrorCode PCSPAISetSp(PC pc, PetscInt sp)

Input Parameters#

pc - the preconditioner
n - 0 or 1

Note#

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.