[petsc-users] using hybrid chebyshev

[Hong Zhang]

Wadud,

The hybrid Chebyshev solver in petsc-3.3 was experimental and only
partially done.
I made an update to petsc-dev and added a test
https://bitbucket.org/petsc/petsc-dev/commits/ee234e7e6a79c7eca4f3878f5409a67d7172e12e

Currently, only runtime options are provided, e.g.
petsc-dev/src/ksp/ksp/examples/tests>./ex39 -beta -0.6 -ksp_type
chebyshev -h | grep cheby
      chebyshev gmres tcqmr bcgs ibcgs fbcgs fbcgsr bcgsl cgs tfqmr cr
pipecr lsqr preonly qcg bicg fgmres minres symmlq lgmres lcd gcr
pgmres specest dgmres (KSPSetType)
  -ksp_chebyshev_eigenvalues <0>: extreme eigenvalues
(KSPChebyshevSetEigenvalues)
  -ksp_chebyshev_estimate_eigenvalues <-1>: estimate eigenvalues using
a Krylov method, then use this transform for Chebyshev eigenvalue
bounds (KSPChebyshevSetEstimateEigenvalues)
  -ksp_chebyshev_hybrid: <FALSE> Use hybrid Chebyshev ()
  -ksp_chebyshev_hybrid_chebysteps <20000>: Number of Chebyshev steps
in hybrid Chebyshev ()
  -ksp_chebyshev_hybrid_gmressteps <10>: Number of adaptive/GMRES
steps in hybrid Chebyshev ()
  -ksp_chebyshev_hybrid_purification: <TRUE> Use purification in
hybrid Chebyshev ()

Let us know if you encounter any problem or want any update when using
Hybrid Chebyshev.

Hong

On Fri, Jan 25, 2013 at 9:16 AM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> KSPCHEBYSHEV (or -ksp_type chebyshev). The hybrid option is
> -ksp_chebyshev_hybrid (see -help for related options). There is currently no
> functional interface in code, just the options database.
>
>
> On Fri, Jan 25, 2013 at 8:56 AM, <Wadud.Miah at awe.co.uk> wrote:
>>
>> The changelog of PETSc 3.3-p5 says that it now provides a hybrid Chebyshev
>> solver. What parameter do you pass into the Fortran KSPSetType subroutine to
>> use this solver?
>>
>>
>>
>> Regards,
>>
>>
>>
>> --------------------------
>>
>> Wadud Miah
>> HPC, Design Physics Division
>> Direct: 0118 98 56220
>> AWE, Aldermaston, Reading, RG7 4PR
>>
>>
>>
>>
>>
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>
>