#include "petscsf.h" PetscErrorCode PetscSFGetGraph(PetscSF sf,PetscInt *nroots,PetscInt *nleaves,const PetscInt **ilocal,const PetscSFNode **iremote)Not Collective
| nroots | - number of root vertices on the current process (these are possible targets for other process to attach leaves) | |
| nleaves | - number of leaf vertices on the current process, each of these references a root on any process | |
| ilocal | - locations of leaves in leafdata buffers | |
| iremote | - remote locations of root vertices for each leaf on the current process |