[Dune] Intersection iterator and global labels of vertices

[Sacconi, Andrea]

Hi,

this does shed light on the problem, thanks!
However, I think I'm missing the last bit: I get an error by calling

indexSet.template subIndex <1> ( * intersectionIter , 0 , 2 );
indexSet.template subIndex <1> ( * intersectionIter , 1,  2 );

The compiler tells me that it can't accept Intersection as first argument. But from the documentation I read that a codim-1 entity is needed ....
Just to recap: I'm interested in the labels of two vertices (so I'm expecting either 0, or 1, or 2), which have codimension 2. Where am I wrong?

Cheers,
Andrea
__________________________________________________________

Andrea Sacconi
PhD student, Applied Mathematics
AMMP Section, Department of Mathematics, Imperial College London,
London SW7 2AZ, UK
a.sacconi11 at imperial.ac.uk
________________________________
From: Dedner, Andreas [A.S.Dedner at warwick.ac.uk]
Sent: 03 May 2013 22:30
To: Sacconi, Andrea; dune at dune-project.org
Subject: RE: Intersection iterator and global labels of vertices

Its called
indexInInside
on the intersection iterator.
The subIndex is on the index set (get that from the gridpart).
So
1) you get the number of the edge from the intersection iterator
2) you get the indexSet from the gridpart
3) you use the subindex method on the indexset to obtain the index of the two vertices
    of that edge.
Best
Andreas

________________________________
From: Sacconi, Andrea [a.sacconi11 at imperial.ac.uk]
Sent: 03 May 2013 22:21
To: Dedner, Andreas; dune at dune-project.org
Subject: RE: Intersection iterator and global labels of vertices

Hi Andreas,

thanks for your answer.
Sorry but I'm a bit perplexed about the method "numberInSelf()" ... I tried to call it, but I get an error from the compiler, saying that there is no such method.
To which class does it belong? I didn't find it in the documentation.

The subIndex method is from IntersectionIterator? Or from elsewhere?

Cheers,
Andrea
__________________________________________________________

Andrea Sacconi
PhD student, Applied Mathematics
AMMP Section, Department of Mathematics, Imperial College London,
London SW7 2AZ, UK
a.sacconi11 at imperial.ac.uk
________________________________
From: Dedner, Andreas [A.S.Dedner at warwick.ac.uk]
Sent: 03 May 2013 17:26
To: Sacconi, Andrea; dune at dune-project.org
Subject: RE: Intersection iterator and global labels of vertices

Hi.
Definitely a dune question:

Probably the easiest way is to use the codim 1 subentity which (in the case of alberta) corresponds to the intersection, i.e., e=intersection.numberInSelf().
Then you can get the index of your corners for that edge by using the subIndex method.
Best
Andreas


________________________________
From: dune-bounces+a.s.dedner=warwick.ac.uk at dune-project.org [dune-bounces+a.s.dedner=warwick.ac.uk at dune-project.org] on behalf of Sacconi, Andrea [a.sacconi11 at imperial.ac.uk]
Sent: 03 May 2013 17:01
To: dune at dune-project.org
Subject: [Dune] Intersection iterator and global labels of vertices

Hi everyone,

I have a quick question about the Intersection Iterator. Before starting, I'm using AlbertGrid.

Suppose you have a triangle ABC, and you need to perform some operations related to its boundary edges, i.e., the three segments AB, AC, BC.
When you call the intersection iterator, you get three iterators, one for each edge. So far, so good.
But what is the correspondence? I mean, iterator -> geometry().corner(0) gives you the local first corner of the codim-1 entity. To which global vertex does it correspond? A, B or C?

I'm not even sure if this question is related to DUNE in general, or maybe should be addressed to DUNE-FEM.
Thanks for your help!

Andrea

__________________________________________________________

Andrea Sacconi
PhD student, Applied Mathematics
AMMP Section, Department of Mathematics, Imperial College London,
London SW7 2AZ, UK
a.sacconi11 at imperial.ac.uk
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