# ISBlockGetSize
Returns the global number of blocks in parallel in the index set of `ISType` `ISBLOCK` 
## Synopsis
```
#include "petscis.h"     
PetscErrorCode ISBlockGetSize(IS is, PetscInt *size)
```
Not Collective


## Input Parameter

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



## Output Parameter

- ***size -*** the global number of blocks





## See Also
 [](sec_scatter), `IS`, `ISGetBlockSize()`, `ISBlockGetLocalSize()`, `ISGetSize()`, `ISCreateBlock()`, `ISBLOCK`

## Level
intermediate

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

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/is/is/impls/block/block.c.html#ISBlockGetSize_Block">ISBlockGetSize_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)  
