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[Evan Lezar <evanlezar@xxxxxxxxx>]

Hi

Since I last rasied this issue there have been a lot of changes (great ones
I must add) to the fenics codebase, so I thought I would ask again.

I am interested in removing the rows and columns of the finite element
matrices (for vector electromagnetic problems) associated with zero valued
Dirichlet boundary conditions.  It is important that the original degrees of
freedom (or a mapping between the two sets) be available so that the
solution of a system of equations or an eigenvalue problem can be used to
visualize the solution, for example.

The removal of the degrees of freedom has two advantages that I can think of
(for my applications at any rate).  The first is that the systems being
solved will be smaller.  The second is of particular concern to me as I am
often solving eigenvalue problems and the unity eigenvalues that are
introduce when applying the Dirichlet BCs in their current form contaminate
the spectrum in many of my examples.

Any thoughts or assistance would be greatly appreciated.

Thanks
Evan