# ISSetLayout
set PetscLayout describing index set layout 
## Synopsis
```
#include "petscis.h" 
PetscErrorCode ISSetLayout(IS is, PetscLayout map)
```
Collective


## Input Arguments

- ***is -*** the index set
- ***map -*** the layout





## Notes
Users should typically use higher level functions such as ISCreateGeneral().

This function can be useful in some special cases of constructing a new IS, e.g. after ISCreate() and before ISLoad().
Otherwise, it is only valid to replace the layout with a layout known to be equivalent.


## See Also
 `ISCreate()`, `ISGetLayout()`, `ISGetSize()`, `ISGetLocalSize()`

## Level
developer

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


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


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