PETSc version 3.17.0
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# DMStagCreate2d

Create an object to manage data living on the elements, edges, and vertices of a parallelized regular 2D grid.

### Synopsis

    PETSC_EXTERN PetscErrorCode DMStagCreate2d(MPI_Comm comm, DMBoundaryType bndx,DMBoundaryType bndy, PetscInt M,PetscInt N, PetscInt m,PetscInt n, PetscInt dof0, PetscInt dof1, PetscInt dof2, DMStagStencilType stencilType, PetscInt stencilWidth, const PetscInt lx[], const PetscInt ly[],DM* dm)

Collective

### Input Parameters

| comm | - MPI communicator
| bndx,bndy | - boundary type: DM_BOUNDARY_NONE, DM_BOUNDARY_PERIODIC, or DM_BOUNDARY_GHOSTED
| M,N | - global number of grid points in x,y directions
| m,n | - number of ranks in the x,y directions (may be PETSC_DECIDE)
| dof0 | - number of degrees of freedom per vertex/0-cell
| dof1 | - number of degrees of freedom per face/1-cell
| dof2 | - number of degrees of freedom per element/2-cell
| stencilType | - ghost/halo region type: DMSTAG_STENCIL_NONE, DMSTAG_STENCIL_BOX, or DMSTAG_STENCIL_STAR
| stencilWidth | - width, in elements, of halo/ghost region
| lx,ly | - arrays of local x,y element counts, of length equal to m,n, summing to M,N

### Output Parameter

| dm | - the new DMStag object

### Options Database Keys

| -dm_view | - calls DMViewFromOptions() a the conclusion of DMSetUp()
| -stag_grid_x <nx> | - number of elements in the x direction
| -stag_grid_y <ny> | - number of elements in the y direction
| -stag_ranks_x <rx> | - number of ranks in the x direction
| -stag_ranks_y <ry> | - number of ranks in the y direction
| -stag_ghost_stencil_width | - width of ghost region, in elements
| -stag_boundary_type_x <none,ghosted,periodic> | - DMBoundaryType value
| -stag_boundary_type_y <none,ghosted,periodic> | - DMBoundaryType value

### Notes

You must call DMSetUp() after this call, before using the DM. If you wish to use the options database (see the keys above) to change values in the DMStag, you must call DMSetFromOptions() after this function but before DMSetUp().

### See Also

DMSTAG, DMStagCreate1d(), DMStagCreate3d(), DMDestroy(), DMView(), DMCreateGlobalVector(), DMCreateLocalVector(), DMLocalToGlobalBegin(), DMDACreate2d()

### Level

beginner

### Location

src/dm/impls/stag/stag2d.c

### Examples

src/dm/impls/stag/tutorials/ex2.c.html
src/dm/impls/stag/tutorials/ex4.c.html
src/dm/impls/stag/tutorials/ex6.c.html
Index of all DMSTAG routines
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Index of all manual pages