Transition to Generic Reference Elements
[Generic Reference Elements]

New Header File and Class Name

To obtain the new reference element include the file and use the new reference element class

  dune/grid/common/genericreferenceelements.hh
  Dune::GenericReferenceElements
  Dune::GenericReferenceElement

instead of

  dune/grid/common/referenceelements.hh
  Dune::ReferenceElements
  Dune::ReferenceElement

The interface of the GenericReferenceElements and of the GenericReferenceElement is the same as before.

Methods for the new SubEntity Numbering

In order to facilitate the transition we introduced new method names for methods that rely on a numbering. Methods in the second column of the table below will give you the old numbering, and methods in the third column will give you the new one. In many cases the new names are also more meaningful. The old methods still work, but they are deprecated and will be removed for Dune 1.4.

class	deprecated method with old numbering	method with new numbering
Entity<0>	entity	subEntity
Intersection	numberInSelf	indexInInside
	numberInNeighbor	indexInOutside
IndexSet	subIndex<c>(...)	subIndex(...,c)
IdSet	subId<c>(...)	subId(...,c)
Mapper	map<c>(...)	map(...,c)
	contains<c>(...)	contains(...,c,result)
Geometry	operator[] (returns reference)	corner (returns value)

Permanently Switching off old Numbering

If you don't want to rely on deprecation warnings and make sure that your code really doesn't use any old numbering stuff, then you can configure Dune with --disable-old-numbering. If this is set, all methods providing old numbers are removed from the header files.

Numbering Conversion Utility

To map a new subentity number to an old number or vice versa use the methods provided by the static methods of the class GenericGeometry::MapNumberingProvider. To obtain for a given reference element of a fixed dimension and dune geometry type the new number for a new subentity of given codimension given the old one (or vice versa) use

  // get class with static methods 
  // using the dimension of the reference elements
    typedef GenericGeometry::MapNumberingProvider< dimension > 
            Numbering;

  // obtain the number of the dune reference element 
  // in the new numbering provided by the generic geometries
    const unsigned int tid = 
          GenericGeometry::topologyId( duneGeometryType );

  // for a subentity<codimension,oldNumber> get the new number
    newNumber = Numbering::template 
                dune2generic< codimension >( tid, oldNumber );
  // for a subentity<codimension,newNumber> get the old number
    oldNumber = Numbering::template 
                generic2dune< codimension >( tid, newNumber );

Change in Numbering

Geometry type	Codim 1	Codim 2	Codim 3
(Simplex,1)	identity
(Cube,1)	identity
(Simplex,2)	2-index	identity
(Cube,2)	identity	identity
(Simplex,3)	3-index	xchg(1,2)	identity
(Cube,3)	identity	xchg(6,8), xchg(7,9)	identity
(Prism,3)	see below	see below	identity
(Pyramid,3)	see below	see below	xchg(3,2)

Prism

	Dune to generic	generic to Dune
Codim 1	(3,0,2,1,4)	(1,3,2,0,4)
Codim 2	(3,5,4,0,1,2,6,8,7)	(3,4,5,0,2,1,6,8,7)

Generic reference element

Face Numbering

Edge Numbering

Dune reference element

Face Numbering

Edge Numbering

Pyramid

	Dune to generic	generic to Dune
Codim 1	(0,3,2,4,1)	(0,4,2,1,3)
Codim 2	(2,1,3,0,4,5,7,6)	(3,1,0,2,4,5,7,6)

Generic reference element

Face Numbering

Edge Numbering

Dune reference element

Face Numbering

Edge Numbering