# SNESMultiblockSetIS
Sets the global row indices for one particular block in a `SNESMULTBLOCK` solver 
## Synopsis
```
#include "petscsnes.h" 
PetscErrorCode SNESMultiblockSetIS(SNES snes, const char name[], IS is)
```
Logically Collective


## Input Parameters

- ***snes -*** the solver context
- ***name -*** name of this block, if NULL the number of the block is used
- ***is   -*** the index set that defines the global row indices in this block



## Notes
Use `SNESMultiblockSetFields()`, for blocks defined by strides.

This function is called once per block (it creates a new block each time). Solve options
for this block will be available under the prefix -multiblock_BLOCKNAME_.




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

## Level
intermediate

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

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/multiblock/multiblock.c.html#SNESMultiblockSetIS_Default">SNESMultiblockSetIS_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)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
