PETSc version 3.17.5

MatGetGhosts

Get the global index of all ghost nodes defined by the sparse matrix

#include "petscmat.h" 
PetscErrorCode MatGetGhosts(Mat mat,PetscInt *nghosts,const PetscInt *ghosts[])

Collective on Mat

mat

- the matrix

	nghosts	- number of ghosts (note for BAIJ matrices there is one ghost for each block)
	ghosts	- the global indices of the ghost points

the nghosts and ghosts are suitable to pass into VecCreateGhost()

advanced