dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Sun, Dec 16, 2007 at 09:46:56AM +0000, Garth N. Wells wrote:
> 
> 
> Gideon Simpson wrote:
> > I'm interested in implementing the Elman et al. preconditioner for 
> > Stokes in the fenics suite.  This involves building an approximate schur 
> > complement for the block strucutre matrix
> > A B^T
> > B 0
> > representing the weak form of the stokes operator.  has anyone 
> > experimented, if not with this sort, some sort of block structure using 
> > the fenics front end?
> > 
> >
> 
> No, when using the default uBLAS backend, there aren't any sophisticated 
> preconditioners. You can create a preconditioner which derives from 
> uBLASPreconditioner.
> 
> You can also look at using PETSc which provides a variety of 
> preconditioners.
> 
> Garth

Since this is quite common, maybe we should consider adding a some
abstractions for block systems/preconditioners: BlockMatrix,
BlockPreconditioner?

PyCC has something like this (but only in Python) that we can look at.
Ola knows more about it.

-- 
Anders