[Dune] Element transformation/renumbering in GridFactory

[Simon Praetorius]

Hi Dune community,

I have a question regarding the elements constructed by a grid factory. When inserting elements, it seems not required that the order of the vertices is preserved by the grid, i.e. inserting an element with vertices 0,1,2 might result in an element that has corners 2,0,1. An example is the ALUGrid GridFactory. How can I get this reordering (from a grid-factory), without comparing coordinates? Or better: how can I get the local geometry transformation to get the coordinates transformed from the real grid element coordinates, to coordinates in the original element inserted into the grid-factory?

I need this to construct an element-parametrization in a grid reader. The information the reader has is just its own vertex numbering and from this a parametrization can be constructed. But if the vertex numbering changes, also the local coordinates change and thus this parametrization can not be used anymore.

Best regards,
Simon

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Dr. Simon Praetorius
Institut für Wissenschaftliches Rechnen
Fakultät Mathematik
Technische Universität Dresden
Tel.: TUD-34432
Mail: simon.praetorius at tu-dresden.de
Web: www.math.tu-dresden.de/~spraetor