:orphan:
# VecAssemblyBegin
Begins assembling the vector; that is ensuring all the vector's entries are stored on the correct MPI process. This routine should be called after completing all calls to `VecSetValues()`.
## Synopsis
```
#include "petscvec.h"
PetscErrorCode VecAssemblyBegin(Vec vec)
```
Collective
## Input Parameter
- ***vec -*** the vector
## See Also
[](ch_vectors), `Vec`, `VecAssemblyEnd()`, `VecSetValues()`
## Level
beginner
## Location
src/vec/vec/interface/vector.c
## Examples
src/dm/impls/stag/tutorials/ex1.c
src/dm/impls/stag/tutorials/ex2.c
src/dm/impls/stag/tutorials/ex3.c
src/dm/impls/stag/tutorials/ex4.c
src/dm/impls/stag/tutorials/ex6.c
src/dm/impls/stag/tutorials/ex8.c
src/ksp/ksp/tutorials/ex10.c
src/ksp/ksp/tutorials/ex25.c
src/ksp/ksp/tutorials/ex28.c
src/ksp/ksp/tutorials/ex29.c
src/ksp/ksp/tutorials/ex3.c
## Implementations
VecAssemblyBegin_MPI in src/vec/vec/impls/mpi/pdvec.c
VecAssemblyBegin_Nest in src/vec/vec/impls/nest/vecnest.c
---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/vec/vec/interface/vector.c)
[Index of all Vec routines](index.md)
[Table of Contents for all manual pages](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)