Dear Members,
I want to solve a Block System arising from the Discretization of a
stabilized Finite Element Formulation of the Stokes System.
I have the following Block Structure
A -B^T
B C
The Preconditioner I intend to use is a block preconditioner of the Form
A -B^T
S
where S is an approximation of the Schur Complement. For applying the
inverse of the schur complement I want to use a Stabilized Least Squares
Commutator in the form
S^-1 = (B diag(Q)^-1 B^T + C_1)^-1 (B diag(Q)^-1 A diag(Q)^-1 B^T + C_2)
(B diag(Q)^-1 B^T + C_1)^-1
where Q is the mass matrix and C_1 and C_2 are some additional
stabilization matrices.
I got from the Manual, that I can use the PCFieldSplit preconditioner
for generating the general Block preconditioner as indicated above. And
I also found that I can define some arbitrary PC with PCSHELL. My
question is, if it is possible to use PCSHELL to define the action of
S^-1 as indicated above.
Kind Regards
Elias Karabelas
--
Elias Karabelas, Ph.D.
Medical University of Graz
Institute of Biophysics
Harrachgasse 21/IV
8010 Graz, Austria
Phone: +43 316 380 7759
Email: [email protected]
Web : http://forschung.medunigraz.at/fodok/staff?name=EliasKarabelas
