PETSc version 3.15.5

PCASMCreateSubdomains

Creates the index sets for the overlapping Schwarz preconditioner for any problem on a general grid.

#include "petscpc.h" 
PetscErrorCode  PCASMCreateSubdomains(Mat A, PetscInt n, IS* outis[])

Collective

	A	- The global matrix operator
	n	- the number of local blocks

outis

- the array of index sets defining the subdomains

Note: this generates nonoverlapping subdomains; the PCASM will generate the overlap from these if you use PCASMSetLocalSubdomains()

In the Fortran version you must provide the array outis[] already allocated of length n.

advanced