[petsc-users] understand the restart number and total iteration number in GMRES

[Mike Wick]

Hi:

I am trying to understand the KSPGMRES a little more. In most books (or,
Algorithm 4 in Saad's 1986 paper), I found that the GMRES(m) algorithm
tries to construct a Krylov subspace with size m first, then seek for a
solution that minimize over this space. Therefore, the total iteration
number should be a multiple of the restart number.

Apparently this is not the case in KSPGRMES. I wander if there is any
stopping condition inside the restart algorithm, or if I misunderstand some
part.

Thanks!

Mike
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20180603/376c0d07/attachment.html>