:orphan:
# KSPBICG
Implements the Biconjugate gradient method (similar to running the conjugate gradient on the normal equations). 


## Notes
This method requires that one be apply to apply the transpose of the preconditioner and operator
as well as the operator and preconditioner.

Supports only left preconditioning

See `KSPCGNE` for code that EXACTLY runs the preconditioned conjugate gradient method on the normal equations

See `KSPBCGS` for the famous stabilized variant of this algorithm


## See Also
 [](ch_ksp), `KSPCreate()`, `KSPSetType()`, `KSPType`, `KSP`, `KSPBCGS`, `KSPCGNE`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/impls/bicg/bicg.c.html#KSPBICG">src/ksp/ksp/impls/bicg/bicg.c</A>


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