# PCGalerkinSetRestriction
Sets the restriction operator for the `PCGALERKIN` preconditioner 
## Synopsis
```
#include "petscksp.h" 
PetscErrorCode PCGalerkinSetRestriction(PC pc, Mat R)
```
Logically Collective on pc


## Input Parameters

- ***pc -*** the preconditioner context
- ***R -*** the restriction operator



## Note
Either this or `PCGalerkinSetInterpolation()` or both must be called




## See Also
 `PCCreate()`, `PCSetType()`, `PCType`, `PCGALERKIN`,
`PCGalerkinSetInterpolation()`, `PCGalerkinGetKSP()`

## Level
Intermediate

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

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/galerkin/galerkin.c.html#PCGalerkinSetRestriction_Galerkin">PCGalerkinSetRestriction_Galerkin in src/ksp/pc/impls/galerkin/galerkin.c</A><BR>


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


[Index of all PC routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
