# DMPlexComputeCellGeometryAffineFEM
Assuming an affine map, compute the Jacobian, inverse Jacobian, and Jacobian determinant for a given cell 
## Synopsis
```
#include "petscdmplex.h"   
#include "petscfe.h"       
PetscErrorCode DMPlexComputeCellGeometryAffineFEM(DM dm, PetscInt cell, PetscReal *v0, PetscReal *J, PetscReal *invJ, PetscReal *detJ)
```
Collective on dm


## Input Parameters

- ***dm   -*** the DM
- ***cell -*** the cell



## Output Parameters

- ***v0   -*** the translation part of this affine transform, meaning the translation to the origin (not the first vertex of the reference cell)
- ***J    -*** the Jacobian of the transform from the reference element
- ***invJ -*** the inverse of the Jacobian
- ***detJ -*** the Jacobian determinant





## Fortran Notes
Since it returns arrays, this routine is only available in Fortran 90, and you must
include petsc.h90 in your code.


## See Also
 `DMPlexComputeCellGeometryFEM()`, `DMGetCoordinateSection()`, `DMGetCoordinates()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/plexgeometry.c.html#DMPlexComputeCellGeometryAffineFEM">src/dm/impls/plex/plexgeometry.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex3f90.F90.html">src/dm/impls/plex/tutorials/ex3f90.F90.html</A><BR>


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


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