[Dune] Reference tetrahedron, again

Peter Bastian Peter.Bastian at iwr.uni-heidelberg.de
Thu Jul 21 17:51:32 CEST 2005


Hi,

what is the class ReferenceTopologySet for anyway? I thought, on the
last dune meeting we decided that the reference elements are those that
are in the class ReferenceElement. This class contains a superset of the
information in ReferenceTopologySet and is implemented for more cases.

-- Peter


Adrian Burri schrieb:
> Well, I think the point is that there is no "correct" ordering, so we're
> completely free to choose it to our liking. I don't have a clue where
> the numbering convention in ReferenceTopologySet comes from, but I think
> it is nice for two reasons:
> - I used it in my implementation and don't need to change anything if we
> stick to it
> - the orientation of all faces is the same (inward pointing normal)
> 
> I think it is not up to me to decide whether this  is the best possible
> choice, but if  noone has any objections against it, I would declare it
> as the Dune standard.
> 
> Cheers
> 
> Adi
> 
> P.S. An algorithmic definition of the numbering is this: Given the three
> face vertices, start with the smallest available index and choose the
> rest so that the orientation of all faces is the same (inward pointing,
> in this case).
> 
> Sreejith Pulloor Kuttanikkad wrote:
> 
>> On Thu, Jul 21, 2005 at 02:35:29PM +0200, Adrian Burri wrote:
>>  
>>
>>> Hi,
>>>
>>> the Dune-homepage says nothing about the numbering of the vertices on
>>> faces, but as you can see from the attached program and output, the
>>> numbering in the ReferenceSimplex changed from the way it was in the
>>> ReferenceTopologySet. Can we stick to the way it was in the
>>> ReferenceTopologySet? (I use this numbering convention heavily in
>>> ALU3dGrid and would like to leave it as is...)
>>>   
>>
>>
>>
>> Infact I had no idea how the numbering of the vertices on faces done
>> (basic rule on local numbering of vertices on faces) and thats why the
>> mismatch. could you please explain the basic rule of the numbering
>> convention you following so that i could correct them.
>>
>> sreejith
>>
>>  
>>
>>> Ciao
>>>
>>> Adi
>>>   
>>
>>
>>  
>>
>>> //- System includes
>>> #include <iostream>
>>>
>>> //- Dune includes
>>> #include <dune/grid/common/reftopology.hh>
>>> #include <dune/grid/common/referenceelements.hh>
>>>
>>> using namespace Dune;
>>>
>>> int main() {
>>>  int n;
>>>  const int* faceIdx;
>>>
>>>  const int nFacesTet = 4;
>>>  const int nFacesHexa = 6;
>>>
>>>  std::cout << "Test tetrahedra:" << std::endl;
>>>  std::cout << "----------------" << std::endl;
>>>
>>>  ReferenceSimplexContainer<double, 3> simplexContainer;
>>>  const ReferenceSimplex<double, 3>& referenceTetrahedron =   
>>> simplexContainer(tetrahedron);
>>>
>>>  for (int face = 0; face < nFacesTet; ++face) {
>>>    ReferenceTopologySet::getSubEntities<1,3>(tetrahedron, face,
>>> faceIdx, n);
>>>    std::cout << "Face " << face << ":" << std::endl;
>>>    std::cout << "(ReferenceTopologySet) "
>>>              << "{ " << faceIdx[0]              << ", " << faceIdx[1]
>>>              << ", " << faceIdx[2]              << " }" << std::endl;
>>>
>>>    std::cout << "(ReferenceSimplex) "
>>>              << "{ " << referenceTetrahedron.subentity(face, 1, 0, 3)
>>>              << ", " << referenceTetrahedron.subentity(face, 1, 1, 3)
>>>              << ", " << referenceTetrahedron.subentity(face, 1, 2, 3)
>>>              << " }" << std::endl;
>>>     }
>>>
>>>  std::cout << std::endl;
>>>  std::cout << "Test hexahedra:" << std::endl;
>>>  std::cout << "---------------" << std::endl;
>>>
>>>  ReferenceCubeContainer<double, 3> cubeContainer;
>>>  const ReferenceCube<double, 3>& referenceCube =
>>>    cubeContainer(cube);
>>>  
>>>  for (int face = 0; face < nFacesHexa; ++face) {
>>>    ReferenceTopologySet::getSubEntities<1,3>(hexahedron, face,
>>> faceIdx, n);
>>>
>>>    std::cout << "Face " << face << ":" << std::endl;
>>>    std::cout << "(ReferenceTopologySet) "
>>>              << "{ " << faceIdx[0]              << ", " << faceIdx[1]
>>>              << ", " << faceIdx[2]              << " }" << std::endl;
>>>
>>>    std::cout << "(ReferenceCube) "
>>>              << "{ " << referenceCube.subentity(face, 1, 0, 3)
>>>              << ", " << referenceCube.subentity(face, 1, 1, 3)
>>>              << ", " << referenceCube.subentity(face, 1, 2, 3)
>>>              << " }" << std::endl;
>>>  }
>>> }   
>>
>>
>>  
>>
>>> Test tetrahedra:
>>> ----------------
>>> Face 0:
>>> (ReferenceTopologySet) { 1, 3, 2 }
>>> (ReferenceSimplex) { 1, 2, 3 }
>>> Face 1:
>>> (ReferenceTopologySet) { 0, 2, 3 }
>>> (ReferenceSimplex) { 2, 0, 3 }
>>> Face 2:
>>> (ReferenceTopologySet) { 0, 3, 1 }
>>> (ReferenceSimplex) { 0, 1, 3 }
>>> Face 3:
>>> (ReferenceTopologySet) { 0, 1, 2 }
>>> (ReferenceSimplex) { 0, 1, 2 }
>>> Test hexahedra:
>>> ---------------
>>> Face 0:
>>> (ReferenceTopologySet) { 0, 2, 4 }
>>> (ReferenceCube) { 0, 2, 4 }
>>> Face 1:
>>> (ReferenceTopologySet) { 1, 3, 5 }
>>> (ReferenceCube) { 1, 3, 5 }
>>> Face 2:
>>> (ReferenceTopologySet) { 0, 1, 4 }
>>> (ReferenceCube) { 0, 1, 4 }
>>> Face 3:
>>> (ReferenceTopologySet) { 2, 3, 6 }
>>> (ReferenceCube) { 2, 3, 6 }
>>> Face 4:
>>> (ReferenceTopologySet) { 0, 1, 2 }
>>> (ReferenceCube) { 0, 1, 2 }
>>> Face 5:
>>> (ReferenceTopologySet) { 4, 5, 6 }
>>> (ReferenceCube) { 4, 5, 6 }
>>>   
>>
>>
>>  
>>
>>> _______________________________________________
>>> Dune mailing list
>>> Dune at hal.iwr.uni-heidelberg.de
>>> http://hal.iwr.uni-heidelberg.de/cgi-bin/mailman/listinfo/dune
>>>   
>>
>>
>>
>>  
>>
> 
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> 

-- 
------------------------------------------------------------------
Peter Bastian, IWR,Uni Heidelberg, INF 348,R 020, 69120 Heidelberg
email: Peter.Bastian at iwr.uni-heidelberg.de   Tel: +49 6221 54 4984
WWW: http://www.iwr.uni-heidelberg.de/~Peter.Bastian Fax: ... 8860




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