diff options
Diffstat (limited to 'src/Simplex_tree')
-rw-r--r-- | src/Simplex_tree/include/gudhi/Simplex_tree.h | 31 | ||||
-rw-r--r-- | src/Simplex_tree/test/simplex_tree_unit_test.cpp | 32 |
2 files changed, 51 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))); } } diff --git a/src/Simplex_tree/test/simplex_tree_unit_test.cpp b/src/Simplex_tree/test/simplex_tree_unit_test.cpp index 580d610a..f63ea080 100644 --- a/src/Simplex_tree/test/simplex_tree_unit_test.cpp +++ b/src/Simplex_tree/test/simplex_tree_unit_test.cpp @@ -863,3 +863,35 @@ BOOST_AUTO_TEST_CASE(make_filtration_non_decreasing) { BOOST_CHECK(st == st_other_copy); } + +BOOST_AUTO_TEST_CASE(insert_graph) { + std::cout << "********************************************************************" << std::endl; + std::cout << "INSERT GRAPH" << std::endl; + typedef typename boost::adjacency_list<boost::vecS, boost::vecS, + boost::undirectedS, + boost::property<vertex_filtration_t, double>, + boost::property<edge_filtration_t, double>> Graph; + Graph g(3); + // filtration value 0 everywhere + put(Gudhi::vertex_filtration_t(), g, 0, 0); + put(Gudhi::vertex_filtration_t(), g, 1, 0); + put(Gudhi::vertex_filtration_t(), g, 2, 0); + // vertices don't always occur in sorted order + add_edge(0, 1, 0, g); + add_edge(2, 1, 0, g); + add_edge(2, 0, 0, g); + + typedef Simplex_tree<> typeST; + typeST st1; + st1.insert_graph(g); + BOOST_CHECK(st1.num_simplices() == 6); + + // edges can have multiplicity in the graph unless we replace the first vecS with (hash_)setS + add_edge(1, 0, 0, g); + add_edge(1, 2, 0, g); + add_edge(0, 2, 0, g); + add_edge(0, 2, 0, g); + typeST st2; + st2.insert_graph(g); + BOOST_CHECK(st2.num_simplices() == 6); +} |