PETSc version 3.16.6
PetscSFGetGraph
Get the graph specifying a parallel star forest
Synopsis
#include "petscsf.h"
PetscErrorCode PetscSFGetGraph(PetscSF sf,PetscInt *nroots,PetscInt *nleaves,const PetscInt **ilocal,const PetscSFNode **iremote)
Not Collective
Input Parameter
Output Parameters
| 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 (if returned value is NULL, it means leaves are in contiguous storage)
|
| iremote | - remote locations of root vertices for each leaf on the current process
|
Notes
We are not currently requiring that the graph is set, thus returning nroots=-1 if it has not been set yet
Fortran Notes
The returned iremote array is a copy and must be deallocated after use. Consequently, if you
want to update the graph, you must call PetscSFSetGraph() after modifying the iremote array.
To check for a NULL ilocal use
if (loc(ilocal) == loc(PETSC_NULL_INTEGER)) then
See Also
PetscSFCreate(), PetscSFView(), PetscSFSetGraph()
Level
intermediate
Location
src/vec/is/sf/interface/sf.c
Examples
src/vec/is/sf/tutorials/ex1.c.html
src/vec/is/sf/tutorials/ex1f.F90.html
Implementations
PetscSFGetGraph_Allgatherv in src/vec/is/sf/impls/basic/allgatherv/sfallgatherv.c
PetscSFGetGraph_Alltoall in src/vec/is/sf/impls/basic/alltoall/sfalltoall.c
Index of all PetscSF routines
Table of Contents for all manual pages
Index of all manual pages