BICG
Usage:
-ksp_type bicg
Options: none
Implements the Biconjugate gradient method (essentially running the conjugate gradient on the normal equations).
Constructs a basis for the Krylov subspace using a 3-term bi-orthogonality relation.
A Bi-Lanczos method.
Benefits: Short recursions
Drawbacks: Doesn’t minimize residuals
Not suitable for nonsymmetric system