Not sure if you would need API additions. Can't everything you describe be handled through defining the grid, operator, residual, and projections?
Matt On Sun, Dec 13, 2009 at 8:59 AM, Jed Brown <jed at 59a2.org> wrote: > I can think of a few ways to implement the following multilevel scheme, > but I'm not sure if it's possible/desirable to have DMMG to manage it. > > Finest level (A) : DMComposite[DA_2D(dof=1),DA_3D(dof=4+)] > Intermediate level (B) : DM_2D(dof=3) > Coarsest levels (C1) : DM_2D(dof=1) > OR (C2) : DM_2D(dof=3) > > No matrices are assembled on level A, but the smoother involves 1D > solves within columns. Restriction A->B involves integration and > discarding "slow" quantities. Assembly is available for Level B and > higher matrices. There are two coarsening strategies after B, one > involves a fieldsplit where the coarsest grids are only for a scalar > problem, other coarsens B directly. > > I think grid sequencing and nonlinear multigrid are not important here > because level B does not contain the long time scales for which > globalization would be challenging. So this hierarchy is strictly for > preconditioning. The DMMG interface is rather different from other > components and I recall Barry saying he would like to eventually get rid > of it. Is there an advantage to using it here? Unless I'm missing > something, it would require some additions to the API (which I can do if > it is the right thing to do). > > Jed > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20091213/ebb34a46/attachment.html>
