[petsc-users] different convergence behaviour

[Mark Adams]

>
>
>
> Notice that there are 7 orders of magnitude between the apparent residual
> (using the preconditioner), and the actual residual, Ax - b.
> You are using Hypre, and this generally means the Hypre coarse grid
> operator is crap. Please
>
>
Huh?, this data looks fine, both the true and preconditioned residual stay
separated by about 9 orders of magnitude. This just tells you that the norm
of A (or is it A^-1) is 10^9.  Am I misunderstanding this?
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