diff options
Diffstat (limited to 'src/Simplex_tree/include/gudhi/Simplex_tree.h')
-rw-r--r-- | src/Simplex_tree/include/gudhi/Simplex_tree.h | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree.h b/src/Simplex_tree/include/gudhi/Simplex_tree.h index 1052e287..2dddc518 100644 --- a/src/Simplex_tree/include/gudhi/Simplex_tree.h +++ b/src/Simplex_tree/include/gudhi/Simplex_tree.h @@ -953,7 +953,10 @@ class Simplex_tree { * boost::graph_traits<OneSkeletonGraph>::vertex_descriptor * must be Vertex_handle. * boost::graph_traits<OneSkeletonGraph>::directed_category - * must be undirected_tag. */ + * must be undirected_tag. + * + * If an edge appears with multiplicity, the function will arbitrarily pick + * one representative to read the filtration value. */ template<class OneSkeletonGraph> void insert_graph(const OneSkeletonGraph& skel_graph) { // the simplex tree must be empty @@ -984,18 +987,22 @@ class Simplex_tree { ++e_it) { auto u = source(*e_it, skel_graph); auto v = target(*e_it, skel_graph); - if (u < v) { - // count edges only once { std::swap(u,v); } // u < v - auto sh = find_vertex(u); - if (!has_children(sh)) { - sh->second.assign_children(new Siblings(&root_, sh->first)); - } - - sh->second.children()->members().emplace( - v, - Node(sh->second.children(), - boost::get(edge_filtration_t(), skel_graph, *e_it))); + if (u == v) throw "Self-loops are not simplicial"; + // We cannot skip edges with the wrong orientation and expect them to + // come a second time with the right orientation, that does not always + // happen in practice. emplace() should be a NOP when an element with the + // same key is already there, so seeing the same edge multiple times is + // ok. + // Should we actually forbid multiple edges? That would be consistent + // with rejecting self-loops. + if (v < u) std::swap(u, v); + auto sh = find_vertex(u); + if (!has_children(sh)) { + sh->second.assign_children(new Siblings(&root_, sh->first)); } + + sh->second.children()->members().emplace(v, + Node(sh->second.children(), boost::get(edge_filtration_t(), skel_graph, *e_it))); } } |