:orphan:
# KSPQMRCGS
Implements the QMRCGStab method. 


## Note
Only right preconditioning is supported.


## Contributed by
Xiangmin Jiao (xiangmin.jiao@stonybrook.edu)


## References

- **** -*** Chan, Gallopoulos, Simoncini, Szeto, and Tong (SISC 1994)
- **** -*** Ghai, Lu, and Jiao (NLAA 2019)



## See Also
 [](ch_ksp), `KSPCreate()`, `KSPSetType()`, `KSPType`, `KSP`, `KSPBICG`, `KSPFBICGS`, `KSPBCGSL`, `KSPSetPCSide()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/impls/bcgs/qmrcgs/qmrcgs.c.html#KSPQMRCGS">src/ksp/ksp/impls/bcgs/qmrcgs/qmrcgs.c</A>


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


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