# PCFieldSplitGetIS
Retrieves the elements for a split as an `IS` 
## Synopsis
```
#include "petscpc.h" 
PetscErrorCode PCFieldSplitGetIS(PC pc, const char splitname[], IS *is)
```
Logically Collective


## Input Parameters

- ***pc  -*** the preconditioner context
- ***splitname -*** name of this split



## Output Parameter

- ***is -*** the index set that defines the elements in this split, or `NULL` if the split is not found





## See Also
  [](sec_block_matrices), `PC`, `PCFieldSplitGetSubKSP()`, `PCFIELDSPLIT`, `PCFieldSplitSetIS()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/fieldsplit/fieldsplit.c.html#PCFieldSplitGetIS">src/ksp/pc/impls/fieldsplit/fieldsplit.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ksp/pc/impls/fieldsplit/fieldsplit.c)


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