: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
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/plexsubmesh.c.html#DMPlexCreateCohesiveSubmesh">src/dm/impls/plex/plexsubmesh.c</A>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/plexsubmesh.c.html#DMPlexCreateCohesiveSubmesh_Uninterpolated">DMPlexCreateCohesiveSubmesh_Uninterpolated in src/dm/impls/plex/plexsubmesh.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/plexsubmesh.c.html#DMPlexCreateCohesiveSubmesh_Interpolated">DMPlexCreateCohesiveSubmesh_Interpolated in src/dm/impls/plex/plexsubmesh.c</A><BR>


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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)