#include "petscksp.h" PetscErrorCode KSPChebyshevEstEigSet(KSP ksp,PetscReal a,PetscReal b,PetscReal c,PetscReal d)Logically Collective on KSP Many br
ksp | - the Krylov space context Many br | |
a | - multiple of min eigenvalue estimate to use for min Chebyshev bound (or PETSC_DECIDE) Many br | |
b | - multiple of max eigenvalue estimate to use for min Chebyshev bound (or PETSC_DECIDE) Many br | |
c | - multiple of min eigenvalue estimate to use for max Chebyshev bound (or PETSC_DECIDE) Many br | |
d | - multiple of max eigenvalue estimate to use for max Chebyshev bound (or PETSC_DECIDE) Many br |
minbound = a*minest + b*maxest maxbound = c*minest + d*maxestMany brThe default configuration targets the upper part of the spectrum for use as a multigrid smoother, so only the maximum eigenvalue estimate is used. Many brThe minimum eigenvalue estimate obtained by Krylov iteration is typically not accurate until the method has converged. Many br
If 0.0 is passed for all transform arguments (a,b,c,d), eigenvalue estimation is disabled. Many br
The default transform is (0,0.1; 0,1.1) which targets the "upper" part of the spectrum, as desirable for use with multigrid. Many br
The eigenvalues are estimated using the Lanczo (KSPCG) or Arnoldi (KSPGMRES) process using a random right hand side vector. Many br
Many br
Level:intermediate
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