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 at mcs.anl.gov 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 >> >>---------- > > > -- Nicolas BATHFIELD Chalmers University of Technology Shipping and Marine Technology phone: +46 (0)31 772 1476 fax: +46 (0)31 772 3699
