On Fri, 17 Mar 2017, Boris Boutkov wrote:
I've been spending some time thinking about how to neatly implement
multigrid projections through the existing GenericProjector
interface and would like some input on the following points.
Sorry for the late response; I wasn't sure I understood your
questions, so I took advantage of having Paul Bauman here in person
today to interrogate him about the problems.
- In order to properly insert local projection matrices into the
global projection I need some additional information in the
ProjectionAction parameter of the GenericProjector. Specifically, I
need access to the old dof information (as well as the existing new
dof info) as this dictates where the local projection matrix gets
inserted into the global one.
Right! This is why FValue will need to be a sparse array type like
MetaPhysicL::DynamicSparseNumberArray.
While it seemed originally that I could hijack the Fvalue parameter
information and squeeze old dof info in there, now this appears to
be a problem since Fvalue is also used in Fe all throughout the
Ke/Fe solves.
In theory, that's exactly what we want! DenseMatrix::cholesky_solve()
takes a second template type, precisely so we can do things like
using a DenseMatrix<Real> to solve a problem with DenseVector<DSNA>
data and solution.
In practice... we don't even bother to instantiate that function with
any combinations other than Real+Real, Real+Complex, and (if
--enable-complex) Complex+Complex. So we probably need to move those
function definitions into a dense_matrix_impl.h header that we can
include elsewhere for when we want to instantiate Real+CrazyOOClass.
I'm starting a branch to do some of these things; I'll let you know
after I push to GitHub.
- Additionally, it seems like we may need to update the
ProjectionAction interface to take in Ke and Fe as well.
No! As long as you can solve for Ue, making it another DSNA, then
each entry of Ue is itself a simple matrix row. No need for Ke
afterward or Fe afterward - you get the column index for each entry
from the indices in the sparse array.
---
Roy
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