#120 Inconsistent numbering of the vertices of the reference quad
Metadata
| Property | Value |
|---|---|
| Reported by | Oliver Sander (oliver.sander@tu-dresden.de) |
| Reported at | Apr 18, 2006 10:12 |
| Type | Bug Report |
| Version | Git (pre2.4) [autotools] |
| Operating System | Unspecified / All |
| Last edited by | Christian Engwer (christi@conan.iwr.uni-heidelberg.de) |
| Last edited at | Jul 24, 2006 12:27 |
| Closed by | Oliver Sander (oliver.sander@tu-dresden.de) |
| Closed at | Oct 23, 2006 08:09 |
| Closed in version | 1.0 |
| Resolution | Won't fix |
| Comment | Will not be fixed because: |
- a fix would break ALUGrid code
- nobody really knows how to fix this elegantly
- hardly anybody would benefit from a fix |
Description
Consider the following program which queries the vertices of each subface of the reference quadrilateral
#include <config.h>
#include <dune/grid/common/referenceelements.hh>
int main () {
const Dune::ReferenceElement<double,2>& refElement
= Dune::ReferenceElements<double,2>::general(Dune::GeometryType(Dune::GeometryType::cube,2));
for (int i=0; i<4; i++)
std::cout << "Face: " << i
<< ", (" << refElement.subEntity(i,1,0,2) << ", " << refElement.subEntity(i,1,1,2) <<")" << std::endl;
}
Its output is
Face: 0, (0, 2) Face: 1, (1, 3) Face: 2, (0, 1) Face: 3, (2, 3)
The ordering of the vertices of the different faces is inconsistent. In analogy to the reference triangle one would expect
Face: 0, (2, 0) Face: 1, (1, 3) Face: 2, (0, 1) Face: 3, (3, 2)
This inconsistency leads to difficult-to-track bugs when trying to map dofs on a grid boundary (e.g. a mortar space) to dofs on the whole grid.