KSPCHEBYSHEV#
The preconditioned Chebyshev iterative method
Options Database Keys#
-ksp_chebyshev_eigenvalues <emin,emax> - set approximations to the smallest and largest eigenvalues of the preconditioned operator. If these are accurate you will get much faster convergence.
-ksp_chebyshev_esteig <a,b,c,d> - estimate eigenvalues using a Krylov method, then use this transform for Chebyshev eigenvalue bounds (
KSPChebyshevEstEigSet())-ksp_chebyshev_esteig_steps - number of estimation steps
-ksp_chebyshev_esteig_noisy - use a noisy random number generator to create right-hand side for eigenvalue estimator
Notes#
The Chebyshev method requires both the matrix and preconditioner to be symmetric positive (semi) definite, but it can work as a smoother in other situations
Only support for left preconditioning.
Chebyshev is configured as a smoother by default, targeting the “upper” part of the spectrum.
The user should call KSPChebyshevSetEigenvalues() to get eigenvalue estimates.
See Also#
KSP: Linear System Solvers, KSPCreate(), KSPSetType(), KSPType, KSP,
KSPChebyshevSetEigenvalues(), KSPChebyshevEstEigSet(), KSPChebyshevEstEigSetUseNoisy()
KSPRICHARDSON, KSPCG, PCMG
Level#
beginner
Location#
src/ksp/ksp/impls/cheby/cheby.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages