petsc-3.8.4 2018-03-24

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 application-specific calculations that require manipulating sets of data throughout a logical plane of grid points.

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