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Diffstat (limited to 'src/Toplex_map/include/gudhi/Fake_simplex_tree.h')
| -rw-r--r-- | src/Toplex_map/include/gudhi/Fake_simplex_tree.h | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/src/Toplex_map/include/gudhi/Fake_simplex_tree.h b/src/Toplex_map/include/gudhi/Fake_simplex_tree.h new file mode 100644 index 00000000..5c7e7b12 --- /dev/null +++ b/src/Toplex_map/include/gudhi/Fake_simplex_tree.h @@ -0,0 +1,207 @@ +#ifndef FAKE_SIMPLEX_TREE_H +#define FAKE_SIMPLEX_TREE_H + +#include <gudhi/Filtered_toplex_map.h> +#include <boost/graph/adjacency_list.hpp> + +namespace Gudhi { + +class Fake_simplex_tree : public Filtered_toplex_map { + +public: + + typedef Vertex Vertex_handle; + + typedef Simplex_ptr Simplex_handle; + + /** \brief Inserts a given range `Gudhi::rips_complex::Rips_complex::OneSkeletonGraph` in the simplicial + * complex. */ + template<class OneSkeletonGraph> + void insert_graph(const OneSkeletonGraph& skel_graph); + + /** \brief Expands the simplicial complex containing only its one skeleton until a given maximal dimension as + * explained in \ref ripsdefinition. */ + void expansion(int max_dim); + + /** \brief Returns the number of vertices in the simplicial complex. */ + std::size_t num_vertices(); + + Simplex_ptr_set candidates() const; + + std::size_t dimension() const; + + std::size_t num_simplices() const; + + std::size_t num_vertices() const; + + Simplex simplex_vertex_range(Simplex_ptr &sptr) const; + + std::vector<Simplex_ptr> max_simplices() const; + + std::unordered_set<Simplex_ptr> filtration_simplex_range() const; + + std::unordered_set<Simplex_ptr> skeleton_simplex_range(int d=std::numeric_limits<int>::max()) const; + + std::size_t dimension(Simplex_ptr& sptr) const; + + void assign_filtration(Simplex_ptr& f_simplex, Filtration_value alpha_complex_filtration); + + void make_filtration_non_decreasing(); + +protected: + + /** \internal Does all the facets of the given simplex belong to the complex ? + * \ingroup toplex_map */ + template <typename Input_vertex_range> + bool all_facets_inside(const Input_vertex_range &vertex_range) const; + +}; + +template<class OneSkeletonGraph> +void Fake_simplex_tree::insert_graph(const OneSkeletonGraph& skel_graph){ + typename boost::graph_traits<OneSkeletonGraph>::edge_iterator e_it, + e_it_end; + for (std::tie(e_it, e_it_end) = boost::edges(skel_graph); e_it != e_it_end; ++e_it) { + auto u = source(*e_it, skel_graph); + auto v = target(*e_it, skel_graph); + if(u<v){ + Simplex s; + s.emplace(u); + s.emplace(v); + insert_simplex_and_subfaces(s); + } + } +} + +void Fake_simplex_tree::expansion(int max_dim){ + for(int d=3; d <= max_dim; d++){ + auto cs = candidates(); + if(cs.empty()) return; + for(const Simplex_ptr& sptr: cs){ + Simplex sigma = *sptr; + insert_simplex_and_subfaces(sigma); + } + } +} + +template <typename Input_vertex_range> +bool Fake_simplex_tree::all_facets_inside(const Input_vertex_range &vertex_range) const{ + Simplex sigma(vertex_range); + for(const Simplex& s : facets(sigma)) + if(!filtrations.count(get_key(s))) return false; + return true; +} + +Simplex_ptr_set Fake_simplex_tree::candidates() const{ + Simplex_ptr_set c; + std::unordered_map<Simplex_ptr, std::vector<Vertex>, Toplex_map::Sptr_hash, Toplex_map::Sptr_equal> facets_to_max; + for(const auto& kv : filtrations){ + Simplex sigma (*(kv.first)); + for(Vertex v : sigma){ + sigma.erase(v); + auto sptr = get_key(sigma); + if(!facets_to_max.count(sptr)) facets_to_max.emplace(sptr, std::vector<Vertex>()); + facets_to_max.at(sptr).emplace_back(v); + sigma.insert(v); + } + } + for(const auto& kv : facets_to_max){ + std::unordered_set<Vertex> facets(kv.second.begin(), kv.second.end()); + for(Vertex v : kv.second){ + facets.erase(v); + for(Vertex w : facets){ + Simplex sigma(*(kv.first)); + sigma.insert(v); + sigma.insert(w); + if(all_facets_inside(sigma)) + c.emplace(get_key(sigma)); + } + facets.emplace(v); + } + } + return c; +} + +std::size_t Fake_simplex_tree::dimension() const { + std::size_t max = 0; + for(auto kv : filtrations) + max = std::max(max, kv.first->size()); + return max; +} + +std::size_t Fake_simplex_tree::num_simplices() const { + return filtration_simplex_range().size(); +} + +std::size_t Fake_simplex_tree::num_vertices() const { + std::unordered_set<Vertex> vertices; + for(auto kv : filtrations) + for (Vertex v : *(kv.first)) + vertices.emplace(v); + return vertices.size(); +} + +Simplex Fake_simplex_tree::simplex_vertex_range(Simplex_ptr& sptr) const { + return *sptr; +} + +std::unordered_set<Simplex_ptr> Fake_simplex_tree::filtration_simplex_range() const{ + std::vector<Simplex_ptr> m = max_simplices(); + std::unordered_set<Simplex_ptr> seen; + while(m.begin()!=m.end()){ + Simplex_ptr& sptr = m.back(); + m.pop_back(); + if(seen.find(sptr)!=seen.end()){ + seen.emplace(sptr); + for(Simplex& sigma : facets(*sptr)) + m.emplace_back(get_key(sigma)); + } + } + return seen; +} + +std::unordered_set<Simplex_ptr> Fake_simplex_tree::skeleton_simplex_range(int d) const{ + std::unordered_set<Simplex_ptr> simplices; + for(auto sptr: filtration_simplex_range()) + if(sptr->size()<=d) + simplices.emplace(sptr); + return simplices; +} + +std::vector<Simplex_ptr> Fake_simplex_tree::max_simplices() const{ + std::vector<Simplex_ptr> s; + for(auto kv : filtrations) + s.emplace_back(kv.first); + return s; +} + +std::size_t Fake_simplex_tree::dimension(Simplex_ptr& sptr) const{ + return sptr->size(); +} + + +void Fake_simplex_tree::assign_filtration(Simplex_ptr& f_simplex, Filtration_value alpha_complex_filtration){ + filtrations.emplace(f_simplex,alpha_complex_filtration); +} + +void Fake_simplex_tree::make_filtration_non_decreasing(){ + for(auto yt = filtrations.begin(); yt != filtrations.end(); ++yt) + for (auto it = toplex_maps.begin(); it != toplex_maps.end(); ++it){ + if(it->first == yt -> second) + break; + if(it->second.membership(*(yt->first))) + for(const Simplex_ptr& sptr : it->second.maximal_cofaces(*(yt->first))){ + it->second.erase_maximal(sptr); + toplex_maps.at(yt->second).insert_simplex(*sptr); + filtrations.emplace(sptr,yt->second); + } + } + +} + + + +} //namespace Gudhi + +#endif /* FAKE_SIMPLEX_TREE_H */ + |