# DMAddField
Add a field to a `DM` object. A field is a function space defined by of a set of discretization points (geometric entities) and a discretization object that defines the function space associated with those points. 
## Synopsis
```
#include "petscdm.h"          
#include "petscdmlabel.h"     
#include "petscds.h"     
PetscErrorCode DMAddField(DM dm, DMLabel label, PetscObject disc)
```
Logically collective on dm


## Input Parameters

- ***dm    -*** The `DM`
- ***label -*** The label indicating the support of the field, or NULL for the entire mesh
- ***disc -*** The discretization object





## Notes
The label already exists or will be added to the `DM` with `DMSetLabel()`.

For example, a piecewise continous pressure field can be defined by coefficients at the cell centers of a mesh and piecewise constant functions
within each cell. Thus a specific function in the space is defined by the combination of a `Vec` containing the coefficients, a `DM` defining the
geometry entities, a `DMLabel` indicating a subset of those geometric entities, and a discretization object, such as a `PetscFE`.


## See Also
 `DMSetLabel()`, `DMSetField()`, `DMGetField()`, `PetscFE`

## Level
intermediate

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

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex8.c.html">src/dm/impls/plex/tutorials/ex8.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex11.c.html">src/ts/tutorials/ex11.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex52.c.html">src/ts/tutorials/ex52.c.html</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](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
