Hi Dave,
Thanks for the tip - you were right, and this works better for higher
resolutions now.
all the best
--Colin
From: Dave May
Sent: 19 March 2019 11:25:11
To: Cotter, Colin J
Cc: petsc-users@mcs.anl.gov
Subject: Re: [petsc-users] Confusing Schur
Hi Dave,
>If you are doing that, then you need to tell fieldsplit to use the Amat to
>define the splits otherwise it will define the Schur compliment as
>S = B22 - B21 inv(B11) B12
>preconditiones with B22, where as what you want is
>S = A22 - A21 inv(A11) A12
>preconditioned with B22.
>If your
Dear petsc-users,
I'm solving a 2x2 block system, for which I can construct the Schur
complement analytically (through compatible FEM stuff),
which I can pass as the preconditioning matrix.
When using gmres on the outer iteration, and preonly+lu on the inner iterations
with a Schur
ype.SHIFT)
instead of F.setType(F.Type.PRECOND).
Jose
> El 16 ene 2019, a las 10:32, Cotter, Colin J via petsc-users
> escribió:
>
> Dear PETSc mailing list,
> A SLEPc question, sorry if this is obvious and I missed something.
>
> How do I set the KSP for the ma
Dear PETSc mailing list,
A SLEPc question, sorry if this is obvious and I missed something.
How do I set the KSP for the mass matrix M in the generalised eigenvalue problem
(I'm looking for the eigenvalue with largest magnitude)
Ax = lambda*Mx
?
I can only find how to set the KSP for a
