Re: [petsc-users] Strange GAMG performance for mixed FE formulation

2016-03-04 Thread Mark Adams
And it looks like you have a well behaved Laplacian here (M-matrix) so I would guess 'richardson' would be faster as the smoother, instead of 'chebyshev'. On Fri, Mar 4, 2016 at 5:04 PM, Mark Adams wrote: > You seem to have 3 of one type of solve that is give 'square_graph 1':

Re: [petsc-users] Strange GAMG performance for mixed FE formulation

2016-03-04 Thread Mark Adams
You seem to have 3 of one type of solve that is give 'square_graph 1': 0] PC*GAMG*Coarsen_AGG(): Square Graph on level 1 of 1 to square This has 9 nnz-row and 44% are zero: [0] PC*GAMG*FilterGraph(): 55.7114% nnz after filtering, with threshold 0., 8.79533 nnz ave. So you want to use a

Re: [petsc-users] Saving vector with hdf5 viewer

2016-03-04 Thread Matthew Knepley
On Fri, Mar 4, 2016 at 8:25 AM, Alejandro D Otero wrote: > Hello, I am trying to save some field stored in a vector which has values > associated with vertexes, edges and cells in a DMPlex. > This vector was created (using petsc4py) from a petcs section, setting > this as

Re: [petsc-users] Strange GAMG performance for mixed FE formulation

2016-03-04 Thread Justin Chang
You're right. This is what I have: [0] PCSetUp_*GAMG*(): level 0) N=48000, n data rows=1, n data cols=1, nnz/row (ave)=9, np=1 [0] PC*GAMG*FilterGraph(): 55.7114% nnz after filtering, with threshold 0., 8.79533 nnz ave. (N=48000) [0] PC*GAMG*Coarsen_AGG(): Square Graph on level 1 of 1 to

Re: [petsc-users] Strange GAMG performance for mixed FE formulation

2016-03-04 Thread Justin Chang
Time to solution went from 100 seconds to 30 seconds once i used 10 graphs. Using 20 graphs started to increase in time slightly On Fri, Mar 4, 2016 at 8:35 AM, Justin Chang wrote: > You're right. This is what I have: > > [0] PCSetUp_*GAMG*(): level 0) N=48000, n data

Re: [petsc-users] Strange GAMG performance for mixed FE formulation

2016-03-04 Thread Lawrence Mitchell
> On 4 Mar 2016, at 15:24, Justin Chang wrote: > > So with -pc_gamg_square_graph 10 I get the following: Because you're using gamg inside the fieldsplit, I think you need: -fieldsplit_1_pc_gamg_square_graph 10 > [0] PCSetUp_GAMG(): level 0) N=48000, n data rows=1, n