petsc-3.5.4 2015-05-23

PetscSFGetMultiSF

gets the inner SF implemeting gathers and scatters

Synopsis

#include "petscsf.h" 
PetscErrorCode PetscSFGetMultiSF(PetscSF sf,PetscSF *multi)

Collective

Input Argument

sf -star forest that may contain roots with 0 or with more than 1 vertex

Output Arguments

multi -star forest with split roots, such that each root has degree exactly 1

Notes

In most cases, users should use PetscSFGatherBegin() and PetscSFScatterBegin() instead of manipulating multi directly. Since multi satisfies the stronger condition that each entry in the global space has exactly one incoming edge, it is a candidate for future optimization that might involve its removal.

Examples