:orphan:
# AOSetIS
Sets the `IS` associated with the application ordering. 
## Synopsis
```
#include "petscao.h" 
PetscErrorCode AOSetIS(AO ao, IS isapp, IS ispetsc)
```
Collective


## Input Parameters

- ***ao -*** the application ordering
- ***isapp -*** index set that defines an ordering
- ***ispetsc -*** index set that defines another ordering (may be `NULL` to use the
natural ordering)





## Notes
The index sets isapp and ispetsc are used only for creation of ao.

This routine increases the reference count of isapp and ispetsc so you may/should destroy these arguments after this call if you no longer need them


## See Also
 [](sec_ao), [](sec_scatter), `AO`, `AOCreate()`, `AODestroy()`, `AOPetscToApplication()`, `AOApplicationToPetsc()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/is/ao/interface/ao.c.html#AOSetIS">src/vec/is/ao/interface/ao.c</A>


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[Index of all AO routines](index.md)  
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