# PCHPDDMSetDeflationMat
Sets the deflation space used to assemble a coarser operator. 
## Synopsis
```
#include "petscpc.h" 
PetscErrorCode PCHPDDMSetDeflationMat(PC pc, IS is, Mat U)
```

## Input Parameters

- ***pc -*** preconditioner context
- ***is -*** index set of the local deflation matrix
- ***U -*** deflation sequential matrix stored as a `MATSEQDENSE`





## See Also
 `PCHPDDM`, `PCDeflationSetSpace()`, `PCMGSetRestriction()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/hpddm/pchpddm.cxx.html#PCHPDDMSetDeflationMat">src/ksp/pc/impls/hpddm/pchpddm.cxx</A>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/hpddm/pchpddm.cxx.html#PCHPDDMSetDeflationMat_HPDDM">PCHPDDMSetDeflationMat_HPDDM in src/ksp/pc/impls/hpddm/pchpddm.cxx</A><BR>


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


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