[Dune] Re-ordering of elements in ALUGrid and boundarySegmentIndex()

[Sacconi, Andrea]

Hi all,

I am experiencing a problem I can't solve, maybe you will be able to shed some light on it.

I am using ALUGrid as grid manager; I pass to the grid factory the complete list of vertices, elements and boundary faces, and then I create the grid.
First point, I noticed that ALUGrid performs a re-ordering of the elements.
Now, the problem is, when I traverse the intersections and extract the boundarySegmentIndex() to which I associated somewhere else the appropriate b.c., everything goes wrong, i.e. Neumann and Dirichlet conditions got mixed up on the boundary. I clearly see this from the vtk output: my solution is not the one which is supposed to be.

Does the element re-numbering affect the boundarySegmentIndex()? I switched to Alberta as grid manager, wiithout changing anything else, and in that case the programme works fine.
Am I missing something about ALUGrid I should be aware of?

Thanks in advance!
Cheers,
Andrea
__________________________________________________________

Andrea Sacconi
PhD student, Applied Mathematics
AMMP Section, Department of Mathematics, Imperial College London,
London SW7 2AZ, UK
a.sacconi11 at imperial.ac.uk