Implements the Flexible Conjugate Gradient method (FCG)

Options Database Keys

-ksp_fcg_mmax <N> - maximum number of search directions
-ksp_fcg_nprealloc <N> - number of directions to preallocate
-ksp_fcg_truncation_type <standard,notay> - truncation approach for directions

Contributed by Patrick Sanan


Supports left preconditioning only.

Level: beginner


1. - Notay, Y."Flexible Conjugate Gradients", SIAM J. Sci. Comput. 22:4, 2000
2. - Axelsson, O. and Vassilevski, P. S. "A Black Box Generalized Conjugate Gradient Solver with Inner Iterations and Variable step Preconditioning", SIAM J. Matrix Anal. Appl. 12:4, 1991

.seealso : KSPGCR, KSPFGMRES, KSPCG, KSPFCGSetMmax(), KSPFCGGetMmax(), KSPFCGSetNprealloc(), KSPFCGGetNprealloc(), KSPFCGSetTruncationType(), KSPFCGGetTruncationType()