# DMStagGetCorners
return global element indices of the local region (excluding ghost points) 
## Synopsis
```
PetscErrorCode DMStagGetCorners(DM dm, PetscInt *x, PetscInt *y, PetscInt *z, PetscInt *m, PetscInt *n, PetscInt *p, PetscInt *nExtrax, PetscInt *nExtray, PetscInt *nExtraz)
```
Not Collective


## Input Parameter

- ***dm -*** the `DMSTAG` object



## Output Parameters

- ***x     -*** starting element index in first direction
- ***y     -*** starting element index in second direction
- ***z     -*** starting element index in third direction
- ***m     -*** element width in first direction
- ***n     -*** element width in second direction
- ***p     -*** element width in third direction
- ***nExtrax -*** number of extra partial elements in first direction
- ***nExtray -*** number of extra partial elements in second direction
- ***nExtraz -*** number of extra partial elements in third direction





## Notes
Arguments corresponding to higher dimensions are ignored for 1D and 2D grids. These arguments may be set to NULL in this case.

The number of extra partial elements is either 1 or 0.
The value is 1 on right, top, and front non-periodic domain ("physical") boundaries,
in the x, y, and z directions respectively, and otherwise 0.


## See Also
 [](chapter_stag), `DMSTAG`, `DMStagGetGhostCorners()`, `DMDAGetCorners()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/stag/stagutils.c.html#DMStagGetCorners">src/dm/impls/stag/stagutils.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/stag/tutorials/ex1.c.html">src/dm/impls/stag/tutorials/ex1.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/stag/tutorials/ex2.c.html">src/dm/impls/stag/tutorials/ex2.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/stag/tutorials/ex3.c.html">src/dm/impls/stag/tutorials/ex3.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/stag/tutorials/ex4.c.html">src/dm/impls/stag/tutorials/ex4.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/stag/tutorials/ex6.c.html">src/dm/impls/stag/tutorials/ex6.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/stag/tutorials/ex8.c.html">src/dm/impls/stag/tutorials/ex8.c.html</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/dm/impls/stag/stagutils.c)


[Index of all DMStag routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
