petsc-3.14.6 2021-03-30
ISAllGather
Given an index set (IS) on each processor, generates a large index set (same on each processor) by concatenating together each processors index set.
Synopsis
#include "petscis.h"
PetscErrorCode ISAllGather(IS is,IS *isout)
Collective on IS
Input Parameter
| is | - the distributed index set
|
Output Parameter
| isout | - the concatenated index set (same on all processors)
|
Notes
ISAllGather() is clearly not scalable for large index sets.
The IS created on each processor must be created with a common
communicator (e.g., PETSC_COMM_WORLD). If the index sets were created
with PETSC_COMM_SELF, this routine will not work as expected, since
each process will generate its own new IS that consists only of
itself.
The communicator for this new IS is PETSC_COMM_SELF
See Also
ISCreateGeneral(), ISCreateStride(), ISCreateBlock()
Level
intermediate
Location
src/vec/is/is/utils/iscoloring.c
Index of all IS routines
Table of Contents for all manual pages
Index of all manual pages