# MatSchurComplementAinvType
Determines how to approximate the inverse of the (0,0) block in Schur complement preconditioning matrix assembly routines 
## Synopsis
```
typedef enum {
  MAT_SCHUR_COMPLEMENT_AINV_DIAG,
  MAT_SCHUR_COMPLEMENT_AINV_LUMP,
  MAT_SCHUR_COMPLEMENT_AINV_BLOCK_DIAG,
  MAT_SCHUR_COMPLEMENT_AINV_FULL
} MatSchurComplementAinvType;
```



## See Also
 `MatSchurComplementGetAinvType()`, `MatSchurComplementSetAinvType()`, `MatSchurComplementGetPmat()`, `MatGetSchurComplement()`, `MatCreateSchurComplementPmat()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/include/petscksp.h.html#MatSchurComplementAinvType">include/petscksp.h</A>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/include/petscksp.h)


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