# DMDAVecGetArrayRead
Returns a multiple dimension array that shares data with the underlying vector and is indexed using the global dimensions. 
## Synopsis
```
#include "petscdmda.h"   
PetscErrorCode DMDAVecGetArrayRead(DM da, Vec vec, void *array)
```
Not collective


## Input Parameters

- ***da -*** the distributed array
- ***vec -*** the vector, either a vector the same size as one obtained with `DMCreateGlobalVector()` or `DMCreateLocalVector()`



## Output Parameter

- ***array -*** the array





## Notes
Call `DMDAVecRestoreArrayRead()` once you have finished accessing the vector entries.

In C, the indexing is "backwards" from what expects: array[k][j][i] NOT array[i][j][k]!

If vec is a local vector (obtained with `DMCreateLocalVector()` etc) then the ghost point locations are accessible. If it is
a global vector then the ghost points are not accessible. Of course with the local vector you will have had to do the
appropriate `DMGlobalToLocalBegin()` and `DMGlobalToLocalEnd()` to have correct values in the ghost locations.


## Fortran Notes
From Fortran use `DMDAVecGetArrayReadF90()` and pass for the array type `PetscScalar`,pointer :: array(:,...,:) of the appropriate
dimension. For a `DMDA` created with a dof of 1 use the dimension of the `DMDA`, for a `DMDA` created with a dof greater than 1 use one more than the
dimension of the `DMDA`. The order of the indices is array(xs:xs+xm-1,ys:ys+ym-1,zs:zs+zm-1) (when dof is 1) otherwise
array(0:dof-1,xs:xs+xm-1,ys:ys+ym-1,zs:zs+zm-1) where the values are obtained from
DMDAGetCorners() for a global array or `DMDAGetGhostCorners()` for a local array. Include petsc/finclude/petscdmda.h90 to access this routine.

Due to bugs in the compiler `DMDAVecGetArrayReadF90()` does not work with gfortran versions before 4.5


## See Also
 `DM`, `DMDA`, `DMDAGetGhostCorners()`, `DMDAGetCorners()`, `VecGetArray()`, `VecRestoreArray()`, `DMDAVecRestoreArrayRead()`, `DMDAVecRestoreArrayDOF()`
`DMDAVecGetArrayDOF()`, `DMDAVecGetArray()`, `DMDAVecRestoreArray()`, `DMDAVecGetArrayRead()`, `DMDAVecRestoreArrayRead()`,
`DMStagVecGetArrayRead()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/da/dagetarray.c.html#DMDAVecGetArrayRead">src/dm/impls/da/dagetarray.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/tutorials/ex2.c.html">src/dm/tutorials/ex2.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/tutorials/ex3.c.html">src/dm/tutorials/ex3.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex43.c.html">src/ksp/ksp/tutorials/ex43.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex14.c.html">src/snes/tutorials/ex14.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex15.c.html">src/snes/tutorials/ex15.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex19.c.html">src/snes/tutorials/ex19.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex3.c.html">src/snes/tutorials/ex3.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex3k.kokkos.cxx.html">src/snes/tutorials/ex3k.kokkos.cxx.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex78.c.html">src/snes/tutorials/ex78.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex10.c.html">src/ts/tutorials/ex10.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex13.c.html">src/ts/tutorials/ex13.c.html</A><BR>


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


[Index of all DMDA routines](index.md)  
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[Index of all manual pages](/docs/manualpages/singleindex.md)  
