petsc-3.14.6 2021-03-30
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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 noisy number generator to create right hand side for eigenvalue estimator


The Chebyshev method requires both the matrix and preconditioner to be symmetric positive (semi) definite. Only support for left preconditioning.

Chebyshev is configured as a smoother by default, targetting the "upper" part of the spectrum. The user should call KSPChebyshevSetEigenvalues() if they have eigenvalue estimates.

See Also

KSPCreate(), KSPSetType(), KSPType (for list of available types), KSP,
KSPChebyshevSetEigenvalues(), KSPChebyshevEstEigSet(), KSPChebyshevEstEigSetUseNoisy() KSPRICHARDSON, KSPCG, PCMG




Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages