Hi Ian, (cc'ing back to the list)
> Thanks for the info! This means, then, that the Trilinos sparse direct > solver is off limits and I would need to use one of the sparse direct > solvers to which deal.ii can interface? No, it is more complicated, unfortunately. TriilinosWrappers::BlockSparseMatrix is basically a two-dimensional array of Trilinos matrices. Therefore, any Trilinos algorithm has no understand of a BlockSparseMatrix and you can not use any solver or preconditioner on that. But, you can access each individual block and hand those of to Trilinos solvers/preconditioners. Iterative solvers that belong to deal.ii (for example SolverGMRES) can be used with TriilinosWrappers::BlockSparseMatrix. Direct solvers and preconditioners in general can not use TriilinosWrappers::BlockSparseMatrix directly (umfpack only supports deal matrices). So: either assemble directly into a TrilinosWrappers::SparseMatrix (or copy into one) and then use Trilinos solvers, or use deal.ii solvers and create a block based preconditioner (see step-32 for example). -- Timo Heister http://www.math.tamu.edu/~heister/ _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
