# ISBlockGetIndices
Gets the indices associated with each block in an `ISBLOCK` 
## Synopsis
```
#include "petscis.h"     
PetscErrorCode ISBlockGetIndices(IS is, const PetscInt *idx[])
```
Not Collective


## Input Parameter

- ***is -*** the index set



## Output Parameter

- ***idx -*** the integer indices, one for each block and count of block not indices





## Note
Call `ISBlockRestoreIndices()` when you no longer need access to the indices


## See Also
 [](sec_scatter), `IS`, `ISBLOCK`, `ISGetIndices()`, `ISBlockRestoreIndices()`, `ISBLOCK`, `ISBlockSetIndices()`, `ISCreateBlock()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/is/is/impls/block/block.c.html#ISBlockGetIndices">src/vec/is/is/impls/block/block.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/is/is/tutorials/ex3.c.html">src/vec/is/is/tutorials/ex3.c.html</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/is/is/impls/block/block.c.html#ISBlockGetIndices_Block">ISBlockGetIndices_Block in src/vec/is/is/impls/block/block.c</A><BR>


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