# VecGetArray3dRead
Returns a pointer to a 3d contiguous array that contains this processor's portion of the vector data.  You MUST call VecRestoreArray3dRead() when you no longer need access to the array. 
## Synopsis
```
#include "petscvec.h"   
PetscErrorCode VecGetArray3dRead(Vec x, PetscInt m, PetscInt n, PetscInt p, PetscInt mstart, PetscInt nstart, PetscInt pstart, PetscScalar ***a[])
```
Logically Collective


## Input Parameters

- ***x -*** the vector
- ***m -*** first dimension of three dimensional array
- ***n -*** second dimension of three dimensional array
- ***p -*** third dimension of three dimensional array
- ***mstart -*** first index you will use in first coordinate direction (often 0)
- ***nstart -*** first index in the second coordinate direction (often 0)
- ***pstart -*** first index in the third coordinate direction (often 0)



## Output Parameter

- ***a -*** location to put pointer to the array





## Notes
For a vector obtained from DMCreateLocalVector() mstart, nstart, and pstart are likely
obtained from the corner indices obtained from DMDAGetGhostCorners() while for
DMCreateGlobalVector() they are the corner indices from DMDAGetCorners(). In both cases
the arguments from DMDAGet[Ghost]Corners() are reversed in the call to VecGetArray3dRead().

For standard PETSc vectors this is an inexpensive call; it does not copy the vector values.


## See Also
 `VecGetArray()`, `VecRestoreArray()`, `VecGetArrays()`, `VecGetArrayF90()`, `VecPlaceArray()`,
`VecRestoreArray2d()`, `DMDAVecGetarray()`, `DMDAVecRestoreArray()`, `VecGetArray3d()`, `VecRestoreArray3d()`,
`VecGetArray1d()`, `VecRestoreArray1d()`, `VecGetArray4d()`, `VecRestoreArray4d()`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/interface/rvector.c.html#VecGetArray3dRead">src/vec/vec/interface/rvector.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/vec/vec/interface/rvector.c)


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