petsc3.9.4 20180911
DMDAGetProcessorSubset
Returns a communicator consisting only of the processors in a DMDA that own a particular global x, y, or z grid point (corresponding to a logical plane in a 3D grid or a line in a 2D grid).
Synopsis
#include "petscdmda.h"
PetscErrorCode DMDAGetProcessorSubset(DM da,DMDADirection dir,PetscInt gp,MPI_Comm *comm)
Collective on DMDA
Input Parameters
 da   the distributed array

 dir   Cartesian direction, either DMDA_X, DMDA_Y, or DMDA_Z

 gp   global grid point number in this direction

Output Parameters
comm new communicator
Notes
All processors that share the DMDA must call this with the same gp value
After use, comm should be freed with MPI_Comm_free()
This routine is particularly useful to compute boundary conditions
or other applicationspecific calculations that require manipulating
sets of data throughout a logical plane of grid points.
Not supported from Fortran
Keywords
distributed array, get, processor subset
Level
advanced
Location
src/dm/impls/da/dasub.c
Index of all DMDA routines
Table of Contents for all manual pages
Index of all manual pages