# SNESMultiblockSetBlockSize
Sets the block size for structured block division in a `SNESMULTBLOCK` solver. If not set the matrix block size is used. 
## Synopsis
```
#include "petscsnes.h" 
PetscErrorCode SNESMultiblockSetBlockSize(SNES snes, PetscInt bs)
```
Logically Collective on snes


## Input Parameters

- ***snes -*** the solver context
- ***bs   -*** the block size





## See Also
 `SNESMULTBLOCK`, `SNESMultiblockGetSubSNES()`, `SNESMULTIBLOCK`, `SNESMultiblockSetFields()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/multiblock/multiblock.c.html#SNESMultiblockSetBlockSize">src/snes/impls/multiblock/multiblock.c</A>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/multiblock/multiblock.c.html#SNESMultiblockSetBlockSize_Default">SNESMultiblockSetBlockSize_Default in src/snes/impls/multiblock/multiblock.c</A><BR>


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


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