as a side effect, two-point gradients are now used by default for the
vertex-centered finite volume discretization. (because P1-FE gradients
require the FE shape functions and those are provided by
dune-localfunctions.)
as a consequence, this triggered an update of quite a few reference
solutions: the differences are measurable, but as far as I can see,
the results are compareable. also, this commit regresses the
performance of the test for the reservoir problem with the vertex
centered finite volume scheme a bit. While I would not bet a house on
the reason, I'm pretty sure that this is caused by the switch from P1
FE gradients to two-point ones.
Note that even though I'm the author of this patch, it shamelessly
rips off substantial parts of the @dr-robertk's patch:
https://github.com/OPM/ewoms/pull/69
the in-file lists of authors has been removed in favor of a global
list of authors in the LICENSE file. this is done because (a)
maintaining a list of authors at the beginning of a file is a major
pain in the a**, (b) the list of authors was not accurate in about 85%
of all cases where more than one person was involved and (c) this list
is not legally binding in any way (the copyright is at the person who
authored a given change, if these lists had any legal relevance, one
could "aquire" the copyright of the module by forking it and removing
the lists...)
the only exception of this is the eWoms fork of dune-istl's solvers.hh
file. This is beneficial because the authors of that file do not
appear in the global list. Further, carrying the fork of that file is
required because we would like to use a reasonable convergence
criterion for the linear solver. (the solvers from dune-istl do
neither support user-defined convergence criteria not do the
developers want support for it. (my patch was rejected a few years
ago.))