Can you write down (in matrix notation) what does full VB matrix look like?
Sherry
On Mon, Jun 13, 2022 at 6:20 PM Tang, Qi wrote:
> Sherry,
>
> -mat_superlu_dist_replacetinypivot
> This flag makes superlu_dist back to working for the full VB block as we
> would think. Thanks again for the
Sherry,
-mat_superlu_dist_replacetinypivot
This flag makes superlu_dist back to working for the full VB block as we would
think. Thanks again for the suggestion.
Does this imply anything for the VB block matrix? Are we just unlucky or does
that imply we have tiny terms along the diagonal and
Could that be due to "numerical zero pivot" (caused due to cancellation and
underflow)? You can try to force diagonal to be nonzero.
Looking at the options page:
https://petsc.org/main/docs/manualpages/Mat/MATSOLVERSUPERLU_DIST/
You can enable this one:
-mat_superlu_dist_replacetinypivot
Hi,
Thank you all for your answers.
I have tried your suggestions and here is what I found.
Barry you were right about the first case. But in the second case, I am not
using a Schur fieldsplit but a multiplicative fieldsplit :
-fieldsplit_TEBV_fieldsplit_EBV_pc_type fieldsplit
