DMCreateSubDM#

Returns an IS and DM encapsulating a subproblem defined by the fields passed in. The fields are defined by DMCreateFieldIS().

Synopsis#

#include "petscdm.h"          
#include "petscdmlabel.h"     
#include "petscds.h"     
PetscErrorCode DMCreateSubDM(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)

Not collective

Input Parameters#

dm - The DM object
numFields - The number of fields to select
fields - The field numbers of the selected fields

Output Parameters#

is - The global indices for all the degrees of freedom in the new sub DM, use NULL if not needed
subdm - The DM for the subproblem, use NULL if not needed

Note#

You need to call DMPlexSetMigrationSF() on the original DM if you want the Global-To-Natural map to be automatically constructed

See Also#

DM Basics, DM, DMCreateFieldIS(), DMCreateFieldDecomposition(), DMAddField(), DMCreateSuperDM(), IS, DMPlexSetMigrationSF(), DMDestroy(), DMView(), DMCreateInterpolation(), DMCreateColoring(), DMCreateMatrix(), DMCreateMassMatrix()

Level#

intermediate

Location#

src/dm/interface/dm.c

Examples#

src/snes/tutorials/ex11.c
src/snes/tutorials/ex77.c
src/snes/tutorials/ex63.c
src/snes/tutorials/ex56.c
src/ts/tutorials/ex30.c
src/ts/tutorials/ex77.c

Implementations#

DMCreateSubDM_DA() in src/dm/impls/da/dacreate.c
DMCreateSubDM_Forest() in src/dm/impls/forest/forest.c
DMCreateSubDM_Patch() in src/dm/impls/patch/patch.c
DMCreateSubDM_Plex() in src/dm/impls/plex/plex.c
DMCreateSubDM_Shell() in src/dm/impls/shell/dmshell.c

Index of all DM routines
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Index of all manual pages