On 18 Dec 2015, at 11:00, Buesing, Henrik <HBuesing@eonerc.rwth-aachen.de> wrote:
On 18 Dec 2015, at 10:52, Buesing, Henrik <HBuesing@eonerc.rwth- aachen.de> wrote:
Dear Justin! Dear Lawrence!
So just to be clear... Firedrake reads in the *.msh as well as the *.geo file. So both have to be present? Only the *.msh file is not sufficient?
Oh no, firedrake doesn't touch the geo file. You should only need the msh file.
But going with your example tests/regression/annulus.msh. In the msh file there is no definition of the Physical Line. This is only present in the *.geo file... So how does firedrake know about "9" as index to the boundary?
Aha! The impenetrable gmsh format strikes again: This section of the mesh file: $Elements 56 1 1 2 9 1 1 9 2 1 2 9 1 9 2 3 1 2 9 2 2 10 4 1 2 9 2 10 3 5 1 2 9 3 3 11 6 1 2 9 3 11 4 7 1 2 9 4 4 12 8 1 2 9 4 12 1 9 1 2 9 5 5 13 10 1 2 9 5 13 6 11 1 2 9 6 6 14 12 1 2 9 6 14 7 13 1 2 9 7 7 15 14 1 2 9 7 15 8 15 1 2 9 8 8 16 16 1 2 9 8 16 5 Is the 16 boundary facets, notice the 4th column is "9", indicating the physical ID. This is where the ID comes from. As Justin pointed out, the full description of this format is at http://geuz.org/gmsh/doc/texinfo/gmsh.html#MSH-ASCII-file-format Lawrence