DMStagPopulateLocalToGlobalInjective#

populate an internal 1-to-1 local-to-global map

Synopsis#

#include "petscdmstag.h"   
#include "petscdmproduct.h"   
PetscErrorCode DMStagPopulateLocalToGlobalInjective(DM dm)

Collective

Creates an internal object which explicitly maps a single local degree of freedom to each global degree of freedom. This is used, if populated, instead of SCATTER_REVERSE_LOCAL with the (1-to-many, in general) global-to-local map, when DMLocalToGlobal() is called with INSERT_VALUES. This allows usage, for example, even in the periodic, 1-rank case, where the inverse of the global-to-local map, even when restricted to on-rank communication, is non-injective. This is at the cost of storing an additional VecScatter object inside each DMSTAG object.

Input Parameter#

dm - the DMSTAG object

Notes#

In normal usage, library users shouldn’t be concerned with this function, as it is called during DMSetUp(), when required.

Returns immediately if the internal map is already populated.

Developer Notes#

This could, if desired, be moved up to a general DM routine. It would allow, for example, DMDA to support DMLocalToGlobal() with INSERT_VALUES, even in the single-rank periodic case.

Level#

developer

Location#

src/dm/impls/stag/stagutils.c

Implementations#

DMStagPopulateLocalToGlobalInjective_1d() in src/dm/impls/stag/stag1d.c
DMStagPopulateLocalToGlobalInjective_2d() in src/dm/impls/stag/stag2d.c
DMStagPopulateLocalToGlobalInjective_3d() in src/dm/impls/stag/stag3d.c

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