# VecGetLocalVector
Maps the local portion of a vector into a vector. 
## Synopsis
```
#include "petscvec.h"   
PetscErrorCode VecGetLocalVector(Vec v, Vec w)
```
Collective on v, not collective on w.


## Input parameter

- ***v -*** The vector for which the local vector is desired.



## Output parameter

- ***w -*** Upon exit this contains the local vector.





## Notes
This function is similar to `VecGetArray()` which maps the local
portion into a raw pointer.  `VecGetLocalVector()` is usually about as
efficient as `VecGetArray()` but in certain circumstances
`VecGetLocalVector()` can be much more efficient than `VecGetArray()`.
This is because the construction of a contiguous array representing
the vector data required by `VecGetArray()` can be an expensive
operation for certain vector types.  For example, for GPU vectors
`VecGetArray()` requires that the data between device and host is
synchronized.


## See Also
 [](chapter_vectors), `Vec`, `VecCreateLocalVector()`, `VecRestoreLocalVector()`, `VecGetLocalVectorRead()`, `VecGetArrayRead()`, `VecGetArray()`

## Level
beginner

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

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/impls/nest/vecnest.c.html#VecGetLocalVector_Nest">VecGetLocalVector_Nest in src/vec/vec/impls/nest/vecnest.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/impls/seq/kokkos/veckok.kokkos.cxx.html#VecGetLocalVector_SeqKokkos">VecGetLocalVector_SeqKokkos in src/vec/vec/impls/seq/kokkos/veckok.kokkos.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/impls/seq/seqcuda/veccuda2.cu.html#VecGetLocalVector_SeqCUDA">VecGetLocalVector_SeqCUDA in src/vec/vec/impls/seq/seqcuda/veccuda2.cu</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/impls/seq/seqhip/vechip2.hip.c.html#VecGetLocalVector_SeqHIP">VecGetLocalVector_SeqHIP in src/vec/vec/impls/seq/seqhip/vechip2.hip.c</A><BR>


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


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