:orphan:
# DMRefine
Refines a `DM` object using a standard nonadaptive refinement of the underlying mesh 
## Synopsis
```
#include "petscdm.h"          
#include "petscdmlabel.h"     
#include "petscds.h"     
PetscErrorCode DMRefine(DM dm, MPI_Comm comm, DM *dmf)
```
Collective


## Input Parameters

- ***dm   -*** the `DM` object
- ***comm -*** the communicator to contain the new `DM` object (or `MPI_COMM_NULL`)



## Output Parameter

- ***dmf -*** the refined `DM`, or `NULL`



## Options Database Key

- ***-dm_plex_cell_refiner <strategy> -*** chooses the refinement strategy, e.g. regular, tohex





## Note
If no refinement was done, the return value is `NULL`


## See Also
 [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/interface/dm.c.html#DMRefine">src/dm/interface/dm.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex11.c.html">src/dm/impls/plex/tutorials/ex11.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/tutorials/ex3.c.html">src/dm/tutorials/ex3.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex35.cxx.html">src/ksp/ksp/tutorials/ex35.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex36.cxx.html">src/ksp/ksp/tutorials/ex36.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex65.c.html">src/ksp/ksp/tutorials/ex65.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex73.c.html">src/ksp/ksp/tutorials/ex73.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex56.c.html">src/snes/tutorials/ex56.c</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/composite/pack.c.html#DMRefine_Composite">DMRefine_Composite in src/dm/impls/composite/pack.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/da/da.c.html#DMRefine_DA">DMRefine_DA in src/dm/impls/da/da.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/forest/forest.c.html#DMRefine_Forest">DMRefine_Forest in src/dm/impls/forest/forest.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/moab/dmmbmg.cxx.html#DMRefine_Moab">DMRefine_Moab in src/dm/impls/moab/dmmbmg.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/plexrefine.c.html#DMRefine_Plex">DMRefine_Plex in src/dm/impls/plex/plexrefine.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/redundant/dmredundant.c.html#DMRefine_Redundant">DMRefine_Redundant in src/dm/impls/redundant/dmredundant.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/stag/stag.c.html#DMRefine_Stag">DMRefine_Stag in src/dm/impls/stag/stag.c</A><BR>


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


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