# DMCompositeGetAccess
Allows one to access the individual packed vectors in their global representation. 
## Synopsis
```
#include "petscdmcomposite.h"  
PetscErrorCode DMCompositeGetAccess(DM dm, Vec gvec, ...)
```
Collective on dm


## Input Parameters

- ***dm -*** the `DMCOMPOSITE` object
- ***gvec -*** the global vector



## Output Parameters

- ***Vec* ... -*** the packed parallel vectors, NULL for those that are not needed





## Note
Use `DMCompositeRestoreAccess()` to return the vectors when you no longer need them


## Fortran Note
Fortran callers must use numbered versions of this routine, e.g., DMCompositeGetAccess4(dm,gvec,vec1,vec2,vec3,vec4)
or use the alternative interface `DMCompositeGetAccessArray()`.


## See Also
 `DMCOMPOSITE`, `DM`, `DMCompositeGetEntries()`, `DMCompositeScatter()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/composite/pack.c.html#DMCompositeGetAccess">src/dm/impls/composite/pack.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex21.c.html">src/snes/tutorials/ex21.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex22.c.html">src/snes/tutorials/ex22.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex28.c.html">src/snes/tutorials/ex28.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex14.c.html">src/ts/tutorials/ex14.c.html</A><BR>


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


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