:orphan:
# PCDeflationSetInitOnly
Do only initialization step. Sets initial guess to the solution on the deflation space but does not apply the deflation preconditioner. The additional preconditioner is still applied. 
## Synopsis
```
#include "petscksp.h" 
PetscErrorCode PCDeflationSetInitOnly(PC pc, PetscBool flg)
```
Logically Collective


## Input Parameters

- ***pc  -*** the preconditioner context
- ***flg -*** default `PETSC_FALSE`



## Options Database Key

- ***-pc_deflation_init_only <false> -*** if true computes only the special guess





## See Also
 `PCDEFLATION`

## Level
intermediate

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

## Implementations

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


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


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