PETSc version 3.17.4
Fix/Edit manual page

PetscSFSetGraph

Set a parallel star forest

Synopsis

#include "petscsf.h" 
PetscErrorCode PetscSFSetGraph(PetscSF sf,PetscInt nroots,PetscInt nleaves,PetscInt *ilocal,PetscCopyMode localmode,PetscSFNode *iremote,PetscCopyMode remotemode)
Collective

Input Parameters

sf - star forest
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, pass NULL for contiguous storage (locations must be >= 0, enforced during setup in debug mode)
localmode - copy mode for ilocal
iremote - remote locations of root vertices for each leaf on the current process (locations must be >= 0, enforced during setup in debug mode)
remotemode - copy mode for iremote

Notes

Leaf indices in ilocal must be unique, otherwise an error occurs.

Input arrays ilocal and iremote follow the PetscCopyMode semantics. In particular, if localmode/remotemode is PETSC_OWN_POINTER or PETSC_USE_POINTER, PETSc might modify the respective array; if PETSC_USE_POINTER, the user must delete the array after PetscSFDestroy(). Only if PETSC_COPY_VALUES is used, the respective array is guaranteed to stay intact and a const array can be passed (but a cast to non-const is needed).

Fortran Notes

In Fortran you must use PETSC_COPY_VALUES for localmode and remotemode.

Developer Notes

We sort leaves to check for duplicates and contiguousness and to find minleaf/maxleaf. This also allows to compare leaf sets of two SFs easily.

See Also

PetscSFCreate(), PetscSFView(), PetscSFGetGraph()

Level

intermediate

Location

src/vec/is/sf/interface/sf.c

Examples

src/vec/is/sf/tutorials/ex1.c.html
src/vec/is/sf/tutorials/ex2.c.html
src/vec/is/sf/tutorials/ex1f.F90.html
src/dm/tutorials/swarm_ex3.c.html

Index of all PetscSF routines
Table of Contents for all manual pages
Index of all manual pages