:orphan:
# DMMoabPToRMapping
Compute the mapping from the physical coordinate system for a given element to the canonical reference element. In addition to finding the inverse mapping evaluation through Newton iteration, the basis function at the parametric point is also evaluated optionally. 
## Synopsis
```
#include "petscdt.h" 
#include "petscdmmoab.h"   
PetscErrorCode DMMoabPToRMapping(const PetscInt dim, const PetscInt nverts, const PetscReal *coordinates, const PetscReal *xphy, PetscReal *natparam, PetscReal *phi)
```

## Input Parameters

- ***PetscInt  dim -*** the element dimension (1=EDGE, 2=QUAD/TRI, 3=HEX/TET)
- ***PetscInt nverts -*** the number of vertices in the physical element
- ***PetscReal coordinates -*** the coordinates of vertices in the physical element
- ***PetscReal[3] xphy -*** the coordinates of physical point for which natural coordinates (in reference frame) are sought



## Output Parameters

- ***PetscReal[3] natparam -*** the natural coordinates (in reference frame) corresponding to xphy
- ***PetscReal[nverts] phi -*** the basis functions evaluated at the natural coordinates (natparam)





## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/moab/dmmbfem.cxx.html#DMMoabPToRMapping">src/dm/impls/moab/dmmbfem.cxx</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/dm/impls/moab/dmmbfem.cxx)


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