Hi,
I try to save a matrix in Elemental format to disk. I am doing, where p_matout is of type MATELEMENTAL,
call PetscViewerCreate(PETSC_COMM_WORLD,v_file,ierr)
call PetscViewerPushFormat(v_file,PETSC_VIEWER_NATIVE,ierr)
call
> On Dec 2, 2019, at 2:30 PM, Li Luo wrote:
>
> -snes_mf fails to converge in my case, but -ds_snes_mf_operator works,
> when the original analytic matrix is still used as the preconditioner.
> The timing is several times greater than using the analytic matrix for both
> Jacobian and
Thank you, Barry and Mark.
The "very fast" cases indeed yield good results, that is, the numerical
solution matches the analytical one. Nevertheless, the usage of PCHypre has
eliminated this strange behavior.
I wasn't aware of the GAMG limitations pointed out by Mark. In fact, for
another
Please send a run with optimization turned on (--with-debugging=0 in
./configure) and -log_view without the actual timing information we are just
guessing where the time is spent.
If your problem has a natural block size then using baij should be a bit
faster than aij, but not
Thank you very much! It looks forming an analytic Jacobian is the only
choice.
Best,
Li
On Mon, Dec 2, 2019 at 3:21 PM Matthew Knepley wrote:
> On Mon, Dec 2, 2019 at 4:04 AM Li Luo wrote:
>
>> Thank you for your reply.
>>
>> The matrix is small with only 67500 rows, but is relatively dense
On Mon, Dec 2, 2019 at 4:04 AM Li Luo wrote:
> Thank you for your reply.
>
> The matrix is small with only 67500 rows, but is relatively dense since a
> second-order discontinuous Galerkin FEM is used, nonzeros=23,036,400.
>
This is very dense, 0.5% fill or 340 nonzeros per row.
> The number
Thank you for your reply.
The matrix is small with only 67500 rows, but is relatively dense since a
second-order discontinuous Galerkin FEM is used, nonzeros=23,036,400.
The number of colors is 539 as shown by using -mat_fd_coloring_view:
MatFDColoring Object: 64 MPI processes
type not yet set
