:orphan:
# DMPlexCreateCohesiveSubmesh
Extract from a mesh with cohesive cells the hypersurface defined by one face of the cells. Optionally, a label can be given to restrict the cells.
## Synopsis
```
#include "petscdmplex.h"
#include "petscdmlabel.h"
PetscErrorCode DMPlexCreateCohesiveSubmesh(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM *subdm)
```
## Input Parameters
- ***dm -*** The original mesh
- ***hasLagrange -*** The mesh has Lagrange unknowns in the cohesive cells
- ***label -*** A label name, or `NULL`
- ***value -*** A label value
## Output Parameter
- ***subdm -*** The surface mesh
## Note
This function produces a `DMLabel` mapping original points in the submesh to their depth. This can be obtained using `DMPlexGetSubpointMap()`.
## See Also
[](ch_unstructured), `DM`, `DMPLEX`, `DMPlexGetSubpointMap()`, `DMPlexCreateSubmesh()`
## Level
developer
## Location
src/dm/impls/plex/plexsubmesh.c
## Implementations
DMPlexCreateCohesiveSubmesh_Uninterpolated in src/dm/impls/plex/plexsubmesh.c
DMPlexCreateCohesiveSubmesh_Interpolated in src/dm/impls/plex/plexsubmesh.c
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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/dm/impls/plex/plexsubmesh.c)
[Index of all DMPlex routines](index.md)
[Table of Contents for all manual pages](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)