Draft: Generalize the OneD grid to arbitrary dimensions
Summary
In several applications I need a 1d grid to describe curves embedded into R^n or into another manifold. The OneDGrid
is not directly usable, since it describes just a real interval. One needs a GeometryGrid
or a CurvedGrid
to transform this into an embedded curve. Closed curves would then still be complicated. This MR tries to extend the current implementation of OneDGrid
into a 1d grid with a dimensionworld >= 1
. Essentially this means that the coordinate are now FieldVector<ctype,dimw>
.
ToDo
There are a few things that need to be checked, e.g.

Some ordering of the vertices is used in the implementation. This is not so easy in embedded coordinates. Maybe it is not needed at all. 
In the current implementation some templates are precompiled (explicitly instantiated). This might not be necessary, or just for the 1d1d case.
Edited by Simon Praetorius