[Dune-devel] YaspGrid project status update

[Dominic Kempf]

Dear Dune community,

I am back at working on YaspGrid and would like to share the current
project status and plan with you.

The tensorproduct feature is fully implemented. It will be merged into
master within the following days if nobody objects. You find the code
on my branch feature/yaspgrid-tensorproduct (on the dune-project
server). Some Remarks:
- Yasp now handles coordinates through a coordinate container
(technically this is a policy for storing and handling coordinates) -
which now is its second template parameter. It is defaulted to
EquidistantCoordinateContainer (see dune/grid/yaspgrid/coordinates.hh)
which makes this change fully backwards compatible.
- Tensorproduct grids can be used via the container
TensorproductCoordinateContainer. A Dune::array<std::vector<ctype>> is
used for coordinates.
- The YaspGrid class offers constructors to allow the construction of
a grid without explicitly constructing the coordinate container.
- The "backend file" dune/grid/yaspgrid/grids.hh is deleted. Its
content is instead split into several files: torus.hh contains the
communication infrastructure, ygrid.hh contains the definition of a
Ygrid - the cornerstone of yasps implementation of a structured grid.
ygrid.hh also got a lot of cleanup like the removal of an entire layer
of dynamic polymorphism and documentation was added.
- If you ever fancy to do so, you can change Yasps ctype by changing
the template parameter of the coordinate container.

While this is an important step for YaspGrid, its not the end. As
talked about on the Dune developer meeting in Aachen, Yasp will get
entities of all codimensions and communication on these. I will start
working on that now. Although this will result in a lot more changes,
we decided to merge the tensorproduct feature now, since its been a
long waiting period since the first announcement of the feature.
Additionally, a clean cut will make development easier for the second
project.

I look forward to all your test reports and feedbacks,
Dominic