After upgrading Fenics from 1.3 to 1.6, FacetIterator can not find connected Facets, Please kindly help!

Question

I have following c++ codes:

//get exterior facets connected with a facet.
bool get_exterior( Mesh & mesh, FacetIterator & fi, std::vector & ex)
{
for( FacetIterator a = FacetIterator(fi);!a.end();++a)
{
if(!a->exterior())
continue;
Facet f=Facet(mesh,a->index());
ex.push_back(f);
}
}

It works perfectly on Fenics 1.3. After upgrading to 1.6, The FacetIteractor can only found 1 connected facet which is the facet itself. Can not find other connected facets. Can any one help?

P.S. mesh.init(2,2) was called to make sure face to face connectivity was established.

Thanks!

Answer 1

Connectivity between MeshEntities of the same dimension has been redefined to mean the MeshEntity itself. This is a logical conclusion - the meaning of facet-facet connectivity is ambiguous.

In order to find connections between facets, you can iterate over the vertices (or edges) of the facet, and then over the facets of each vertex (or edge). Probably you will want to use a std::set to collect the indices, as there will be some repetition, and you may wish to delete the original facet itself from the set.

Comments

Got it.

Thank you!