[Dune] GMSH reader fails in reading the same file for AlbertaGrid<2, 3> but not for ALUSimplexGrid<2, 3>

[Felix Albrecht]

On Fri, 2012-07-20 at 18:27 +0000, Sacconi, Andrea wrote:
> Hi Martin,
> 
> yes, I have ALBERTA 2.0.1 installed on my laptop.
> Because I thought it was the last version ... but now I see that there is something new that can be downloaded!

http://www.ians.uni-stuttgart.de/nmh/downloads/alberta/

> I'll try and see what happens with my .msh files.
> 
> 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
> 
> ________________________________________
> From: Martin Nolte [nolte at mathematik.uni-freiburg.de]
> Sent: 20 July 2012 19:01
> To: Sacconi, Andrea
> Subject: Re: [Dune] GMSH reader fails in reading the same file for AlbertaGrid<2, 3> but not for ALUSimplexGrid<2, 3>
> 
> Hi Andrea,
> 
> not checking exactly, I would guess that you are using ALBERTA 2.0 (because
> version 3.0 does not require the elements to be "oriented"). This internal
> requirement by the ALBERTA library (version 2.0). In the special case of a 2d in
> 3d grid, it is possible to generate an "orientation" using the vector product
> (this is, e.g., done internally in ALUGrid), but it does not work for a 4d
> world. Since the restriction is gone in ALBERTA 3.0, I did not bother to
> implement it, though.
> 
> I hope this helps,
> 
> Martin
> 
> On 07/20/2012 07:36 PM, Sacconi, Andrea wrote:
> > Hi everyone,
> >
> > I'm experiencing a problem, again, with the GMSH reader.
> >
> > You will find attached two .msh files.
> >
> > I managed to import a .msh file for a boundaryless surface (representing a
> > sphere, an ellipsoid, ...) into ALUSimplexGrid<2, 3>, eliminating from the .msh
> > all the elements that are not triangles (otherwise the segments would be
> > interpreted as boundary objects, but here there is no boundary at all). Thanks
> > to Andreas Dedner for the useful suggestion.
> >
> > Anyway, if I try to use the same file with AlbertaGrid<2, 3>, this error message
> > appears on my screen:
> >
> > Loading macro grid: ../data/ellipsoid.msh
> > Reading 2d Gmsh grid...
> > version 2.2 Gmsh file detected
> > file contains 92 nodes
> > file contains 178 elements
> > number of real vertices = 91
> > number of boundary elements = 0
> > number of elements = 178
> > Error: GridError [setOrientation:macrodata.cc:259]: Surface grid cannot be oriented.
> >
> > It seems that the same file gives problems with the orientation of the elements,
> > but only in the AlbertaGrid case.
> > Here my questions:
> >
> > 1) are there any specific requirements about the orientation I should pay
> > attention to? Check also the (long, sorry!) post scriptum.
> > 2) why doesn't ALUGrid detect the problem?
> >
> > Cheers,
> >
> > Andrea
> > ________________________
> >
> > PS, if I try with another file, the problem doesn't appear. For example:
> >
> > Loading macro grid: ../data/mesh_GMSH_coarse_new.msh
> > Reading 2d Gmsh grid...
> > version 2.2 Gmsh file detected
> > file contains 19 nodes
> > file contains 32 elements
> > number of real vertices = 18
> > number of boundary elements = 0
> > number of elements = 32
> > macro_test_2d: WARNING in ./../2d/macro_2d.c, line 451
> > There is a cycle beginning in macro element 14.
> > Correcting refinement edges....
> > reorder_2d: Current elem: 0, best_edges: 0 3 3
> > Current elem: 1, best_edges: 2 3 3
> > Current elem: 2, best_edges: 1 3 3
> > Current elem: 3, best_edges: 2 3 3
> > Current elem: 4, best_edges: 0 3 3
> > Current elem: 5, best_edges: 2 3 3
> > Current elem: 6, best_edges: 0 1 2
> > Looking at best_edges[6][0]...
> > Found compatibly divisible neighbour 7!
> > Current elem: 8, best_edges: 0 3 3
> > Current elem: 9, best_edges: 1 3 3
> > Current elem: 10, best_edges: 1 3 3
> > Current elem: 11, best_edges: 2 3 3
> > Current elem: 12, best_edges: 0 3 3
> > Current elem: 13, best_edges: 1 3 3
> > Current elem: 14, best_edges: 1 3 3
> > Current elem: 15, best_edges: 2 3 3
> > Current elem: 16, best_edges: 0 3 3
> > Current elem: 17, best_edges: 0 1 2
> > Looking at best_edges[17][0]...
> > Found compatibly divisible neighbour 19!
> > Current elem: 18, best_edges: 1 3 3
> > Current elem: 20, best_edges: 0 3 3
> > Current elem: 21, best_edges: 1 3 3
> > Current elem: 22, best_edges: 1 3 3
> > Current elem: 23, best_edges: 2 3 3
> > Current elem: 24, best_edges: 0 3 3
> > Current elem: 25, best_edges: 2 3 3
> > Current elem: 26, best_edges: 2 3 3
> > Current elem: 27, best_edges: 1 3 3
> > Current elem: 28, best_edges: 0 3 3
> > Current elem: 29, best_edges: 1 3 3
> > Current elem: 30, best_edges: 1 3 3
> > Current elem: 31, best_edges: 2 3 3
> > check_mesh: checking mesh 'DUNE AlbertaGrid'
> > checking done; no error detected
> > Grid file read correctly.
> >
> > __________________________________________________________
> >
> > Andrea Sacconi
> > PhD student, Applied Mathematics
> > AMMP Section, Department of Mathematics, Imperial College London,
> > London SW7 2AZ, UK
> > a.sacconi11 at imperial.ac.uk
> >
> >
> > _______________________________________________
> > Dune mailing list
> > Dune at dune-project.org
> > http://lists.dune-project.org/mailman/listinfo/dune
> 
> --
> Dr. Martin Nolte <nolte at mathematik.uni-freiburg.de>
> 
> Universität Freiburg                                   phone: +49-761-203-5630
> Abteilung für angewandte Mathematik                    fax:   +49-761-203-5632
> Hermann-Herder-Straße 10
> 79104 Freiburg, Germany
> 
> _______________________________________________
> Dune mailing list
> Dune at dune-project.org
> http://lists.dune-project.org/mailman/listinfo/dune

-- 
--
----------------------------------------------------------- 
 Felix Albrecht 

 Institut fuer Numerische und Angewandte 
 Mathematik, FB Mathematik und Informatik 
 Universitaet Muenster, Room 120.012 
 Orleans-Ring 10 
 D-48149 Muenster 

 Tel.: +49 251 83 35130 
 Fax:  +49 251 83 32729 
 Mail: felix.albrecht at uni-muenster.de 
 WWW:  www.uni-muenster.de/math/u/felix.albrecht/ 
-----------------------------------------------------------