> On 2 Dec 2016, at 16:01, Anna Kalogirou <a.kalogirou@leeds.ac.uk> wrote:
>
> Linear firedrake_0_fieldsplit_3_ solve did not converge due to DIVERGED_DTOL iterations 35
>
> The option
>
> "fieldsplit_3_pc_factor_shift_type": "nonzero"
Given that LU with pivoting ought to invert the block unless it is singular, I think something funky is going on.
Can you additionally run with:
"fieldsplit_3_ksp_monitor_true_residual": True
(In passing, if you're using LU you should probably be setting the ksp_type of these sub solves to "preonly", so you don't bother iterating).
The function space is CG1. I believe that has diagonally dominant mass matrices so we shouldn't actually need pivotting.
Lawrence
_______________________________________________
firedrake mailing list
firedrake@imperial.ac.uk
https://mailman.ic.ac.uk/mailman/listinfo/firedrake