General
The Refinement system allows to temporarily refine a grid or single entities without changing the grid itself. You may want to do this because you want to write your data to a file and have to do subsampling, but want to continue the calculation with the unmodified grid afterwards.
What Refinement can do for you
template<unsigned topologyId, class CoordType,
unsigned coerceToId, int dimension>
class StaticRefinement
{
public:
enum { dimension };
template<int codimension>
struct codim
{
class SubEntityIterator;
};
}
static VertexIterator vEnd(int level)
Get a VertexIterator.
static ElementIterator eEnd(int level)
Get an ElementIterator.
Codim< 0 >::SubEntityIterator ElementIterator
The ElementIterator of the Refinement.
Definition base.cc:126
static ElementIterator eBegin(int level)
Get an ElementIterator.
static VertexIterator vBegin(int level)
Get a VertexIterator.
Codim< dimension >::SubEntityIterator VertexIterator
The VertexIterator of the Refinement.
Definition base.cc:124
typedef CoordVector
The CoordVector of the Refinement.
Definition base.cc:133
static int nVertices(int level)
Get the number of Vertices.
typedef IndexVector
The IndexVector of the Refinement.
Definition base.cc:140
static int nElements(int level)
Get the number of Elements.
The Iterators can do all the usual things that Iterators can do, except dereferencing. In addition, to do something useful, they support some additional methods:
template<unsigned topologyId, class CoordType, unsigned coerceToId, int dimension>
class VertexIterator
{
public:
typedef ImplementationDefined Refinement;
int index() const;
Refinement::CoordVector coords() const;
}
template<unsigned topologyId, class CoordType, unsigned coerceToId, int dimension>
class ElementIterator
{
public:
typedef ImplementationDefined Refinement;
int index() const;
Refinement::CoordVector coords() const;
Refinement::IndexVector vertexIndices() const;
}
How to use it
If you want to write a Refinement implementation for a particular geometry type, e.g. SquaringTheCircle (or a particular set of geometry types) here is how:
- create a file refinement/squaringthecircle.cc and #include "base.cc". Your file will be included by others, so don't forget to protect against double inclusion.
- implement a class (or template class) RefinementImp conforming exactly to the user interface above.
- put it (and it's helper stuff as appropriate) into it's own namespace Dune::RefinementImp::SquaringTheCircle.
- define the mapping of topologyId, CoordType and coerceToId to your implementation by specialising template struct RefinementImp::Traits. It should look like this:
template<class CoordType>
struct Traits<sphereTopologyId, CoordType,
GenericGeometry::CubeTopology<2>::type::id, 2>
{
typedef SquaringTheCircle::RefinementImp<CoordType>
Imp;
};
}
This namespace contains the implementation of Refinement.
Definition base.cc:28
SquaringTheCircle::Refinement Imp
The implementation this specialisation maps to.
Definition base.cc:71
If you implement a template class, you have to specialise struct RefinementImp::Traits for every possible combination of topologyId and coerceToId that your implementation supports.
- #include "refinement/squaringthecircle.cc" from refinement.hh.
This is enough to integrate your implementation into the Refinement system. You probably want to include it into VirtualRefinement also.
Namespaces