[petsc-users] chelosky vs multigrid

[Fazlul Huq]

Thanks a lot.

Sincerely,
Huq

On Mon, Dec 3, 2018 at 10:07 PM Jed Brown <jed at jedbrown.org> wrote:

> Fazlul Huq <huq2090 at gmail.com> writes:
>
> > Thanks.
> >
> > I have tried with large problem also (10^7 X 10^7). Even then I got
> > cholesky faster than multigrid.
> > But, the problem is 1D. May be that's the reason.
>
> Exactly.  Cholesky is O(n) with a very small constant in 1D, O(n^{3/2})
> in 2D, and O(n^2) in 3D.
>


-- 

Fazlul Huq
Graduate Research Assistant
Department of Nuclear, Plasma & Radiological Engineering (NPRE)
University of Illinois at Urbana-Champaign (UIUC)
E-mail: huq2090 at gmail.com
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