]> https://gitweb.dealii.org/ - dealii.git/commit
Make MassOperator's diagonals true diagonals, not lumped ones.
authorDavid Wells <drwells@email.unc.edu>
Thu, 29 Jul 2021 21:40:18 +0000 (17:40 -0400)
committerDavid Wells <drwells@email.unc.edu>
Mon, 16 Aug 2021 20:02:10 +0000 (16:02 -0400)
commit7af998f7d482c5f6994def49951900c6306cf0b8
treec519109ea832d27e9926a4edf38ebe54dbe19b88
parent8ba89c874e9177fd5547689f2e2b7dc3b166a9e1
Make MassOperator's diagonals true diagonals, not lumped ones.

The previous implementation used row sums (i.e., mass lumping) instead of
computing the diagonal. This should be changed for two reasons:
1. It's not really the diagonal (and its inconsistent with LaplaceOperator).
2. Lumped mass matrices are only positive for either low-order elements (where
   the basis functions are all positive) or very well-behaved elements (like
   FE_Q). In particular, the values on the diagonal are either zero or negative
   for TET10 if we use lumping, which isn't going to work.
doc/news/changes/incompatibilities/20210729DavidWells [new file with mode: 0644]
include/deal.II/matrix_free/operators.h

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