this regressed after time step index of the initial solution was
changed from 0 (actually, this was also 0 for the first time step...)
to -1 in b30af664.
this method checks that the difference in the storage terms before and
after a time step is the same as the accumulated fluxes over the
domain boundary plus the source terms.
this is required so that the element-centered finite volume method
does not handle each partition of the domain separately. (i.e. so that
fluxes accross faces on the process boundaries are considered) mea culpa!
The fix for this is to also include these entries in the matrix which
uses domestic indices. This required some rather extensive changes to
the blacklisting mechanism as for this it must be possible to
translate the index of a blacklisted entity (i.e., an entity in a
ghost or an overlap cell) to a domestic index (i.e., the corresponding
index in the algebraic overlap).
Note that the code for algebraic overlaps is *fun* and the person who
wrote it should be tarred and feathered. (*ouch* ;)) Seriously: Better
approaches than "lets-throw-this-away-and-use-grid-overlaps" are
deeply appreciated. (The grid overlap is not really useful in Dune
because only "Mickey Mouse grids" like Dune::YaspGrid support it.)
... and actually use it for the lens problems. This seems to have been
disabled for debugging and later it was probably forgotten to turn it
on again. This led to some minor bit-rot in that code...
The reason for this is to be able to modify the tolerance according to
grid size: The NewtonTolerance parameter has been renamed to
NewtonRawTolerance and for the porous media models is divided by the
square root of the volume of the smallst finite volume in the grid to
get the final tolerance for the Newton method. This is necessary
because very large grids need to achive a higher volumetric accuracy
in the residual than very small ones...
basically the init() method was split into a finishInit() method which
fills the data structures allocated in the constructor with meaningful
data and into applyInitialSolution() which does just that (and no
more!)
"intensive" means that the value of these quantities at a given
spatial location does not depend on any value of the neighboring
intensive quantities. In contrast, "extensive" quantities depend in
the intensive quantities of the environment of the spatial location.
this change is necessary is because the previous nomenclature was very
specific to finite volume discretizations, but the models themselves
were already rather generic. (i.e., "volume variables" are the
intensive quantities of finite volume methods and "flux variables"
are the extensive ones.)
For some reason, it changed because of the transition to the primary
variable switching approach. Because I trust the new result more than
the old, let's make this the new reference solution.
because "manager" sounds less religious than "creator" and the
GridCreators did all kinds of other stuff besides creating the grid.
this patch also gets rid of the static function inside these classes,
which should make them easier to understand...
this also comes with moving responsibilities around and some smaller
cleanups for the grid creation. (although grid creation could be
possibly done by the simulator now, the GridCreator concept has not
been abandoned, yet...)
