#178 MCMGMapper not usable for P2 functions on prisms

Metadata

Property	Value
Reported by	Oliver Sander (oliver.sander@tu-dresden.de)
Reported at	Sep 12, 2006 08:16
Type	Bug Report
Version	Git (pre2.4) [autotools]
Operating System	Unspecified / All
Closed by	Oliver Sander (oliver.sander@tu-dresden.de)
Closed at	Dec 7, 2006 15:26
Closed in version	Unknown
Resolution	Not a bug
Comment	This was not a bug but a misunderstanding on my part.

Description

Please apologize if the following is not a bug but a feature.

There is a conceptual loophole in the MultipleCodimMultipleGeomTypeMapper. It allows to attach degrees of freedom to subentities of elements. So supposedly this is the method of choice when programming second-order Lagrangian finite elements. The implementations uses a Layout class, which, given a codimension and a geometry type, returns whether subentities of the given geometry type and of the given codimension have a dof or not.

Thus, for example, a mapper for P2 elements would return true for codims 3 and 2 for tetrahedra, and for codims 3,2,1,0 for hexahedra. However, here's the problem: What happens with prisms and pyramids? There, only some codim 1 entities (the quadrilaterals) get a dof. However, the interface of the Layout classes is too restricted to be able to convey this information.