:orphan:
# DMCreateRestriction
Gets restriction matrix between two `DM` objects. The resulting matrix map degrees of freedom in the vector obtained by `DMCreateGlobalVector()` on the fine `DM` to similar vectors on the coarse grid `DM`.
## Synopsis
```
#include "petscdm.h"
#include "petscdmlabel.h"
#include "petscds.h"
PetscErrorCode DMCreateRestriction(DM dmc, DM dmf, Mat *mat)
```
Collective
## Input Parameters
- ***dmc -*** the `DM` object
- ***dmf -*** the second, finer `DM` object
## Output Parameter
- ***mat -*** the restriction
## Note
This only works for `DMSTAG`. For many situations either the transpose of the operator obtained with `DMCreateInterpolation()` or that
matrix multiplied by the vector obtained with `DMCreateInterpolationScale()` provides the desired object.
## See Also
[](ch_dmbase), `DM`, `DMRestrict()`, `DMInterpolate()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateInterpolation()`
## Level
developer
## Location
src/dm/interface/dm.c
## Examples
src/dm/impls/stag/tutorials/ex4.c
## Implementations
DMCreateRestriction_Stag in src/dm/impls/stag/stag.c
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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)