#include "petscsf.h" PetscErrorCode PetscSFSetGraph(PetscSF sf,PetscInt nroots,PetscInt nleaves,const PetscInt *ilocal,PetscCopyMode localmode,const PetscSFNode *iremote,PetscCopyMode remotemode)Collective
| 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 |
Developers Note: Local indices which are the identity permutation in the range [0,nleaves) are discarded as they encode contiguous storage. In such case, if localmode is PETSC_OWN_POINTER, the memory is deallocated as it is not needed
Developers Note: This object does not necessarily encode a true star forest in the graph theoretic sense, since leaf indices are not required to be unique. Some functions, however, rely on unique leaf indices (checked in debug mode).