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Re: PETSC-Hypre: number of level with boomeramg



Try -pc_hypre_boomeramg_print_statistics in the console for more information regarding your AMG.

I believe that is the right syntax. I am not 100% though! It is a long time ago I touched it.

With best regards, Shaman Mahmoudi

On Jan 25, 2007, at 3:31 PM, Nicolas Bathfield wrote:

Dear Fernando,

Thanks for your reply.

I had notice the value maxlevels given by -ksp_view, but I did not know
how to change this value.


Still, as the default is 25 levels I think, I have no way to know exactly
how many levels are used for a given case.
I can reformulate my question in this way: does boomeramg coarsen the
"grid" to the coarsest level possible, i.e. 1 cell over the domain, or
does it stop before that? (grid is not the right term when it comes to
algebraic multilevel methods, but I can't find any other clear way to
express it). How can I control the coarsening?


Thinking about it, perhaps boomeramd actually refines the grid up to the
maximum number of levels...Is it so?


Thanks for your help.

Nicolas

Nicolas,

You should try the option -pc_hypre_boomeramg_max_levels in the line
command. In order to see the level's details you can use the PESTc option
-ksp_view.


Best Regards

Fernando.


Em (11:15:45), petsc-users@xxxxxxxxxxx escreveu:


Hi Petsc users,

I have a question regarding the use of Hypre and especially Boomeramg.
How can we control the number of levels in the multigrid algortihm? Can
we
chose it, or if not, can we display it in some way?


Best regards,

Nicolas.

--
Nicolas BATHFIELD
Chalmers University of Technology
Shipping and Marine Technology
phone: +46 (0)31 772 1476
fax: +46 (0)31 772 3699

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--
Nicolas BATHFIELD
Chalmers University of Technology
Shipping and Marine Technology
phone: +46 (0)31 772 1476
fax:   +46 (0)31 772 3699