[petsc-users] how to set the full gmres by the ksp gmres

[Jed Brown]

On Sat, 4 Sep 2010 22:30:04 +0800, Liu Lin 刘林 <sixthseason at gmail.com> wrote:
> Hi, anywho!
> 
> how to set the full gmres by the ksp gmres?

Do you mean GMRES without restart?  Just set a big restart

  -ksp_gmres_restart <30>: Number of Krylov search directions (KSPGMRESSetRestart)

Also useful if GMRES is having trouble for a nasty problem:

    -ksp_gmres_classicalgramschmidt: Classical (unmodified) Gram-Schmidt (fast) (KSPGMRESSetOrthogonalization)
    -ksp_gmres_modifiedgramschmidt: Modified Gram-Schmidt (slow,more stable) (KSPGMRESSetOrthogonalization)

Jed