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Diffstat (limited to 'src/Bottleneck_distance/include/gudhi/Planar_neighbors_finder.h')
-rw-r--r-- | src/Bottleneck_distance/include/gudhi/Planar_neighbors_finder.h | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/Bottleneck_distance/include/gudhi/Planar_neighbors_finder.h b/src/Bottleneck_distance/include/gudhi/Planar_neighbors_finder.h new file mode 100644 index 00000000..9356e879 --- /dev/null +++ b/src/Bottleneck_distance/include/gudhi/Planar_neighbors_finder.h @@ -0,0 +1,216 @@ +/* This file is part of the Gudhi Library. The Gudhi library + * (Geometric Understanding in Higher Dimensions) is a generic C++ + * library for computational topology. + * + * Author(s): Francois Godi + * + * Copyright (C) 2015 INRIA Sophia-Antipolis (France) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_ +#define SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_ + +#include <list> +#include <map> +#include "../CGAL/Kd_tree.h" +#include "../CGAL/Miscellaneous.h" +#include <gudhi/Persistence_diagrams_graph.h> + + +namespace Gudhi { + +namespace Bottleneck_distance { + +/** \internal \brief Structure used to find any point in V near (according to the planar distance) to a query point from U. + * + * V points have to be added manually using their index and before the first remove/pull. A neighbor pulled is automatically removed. but we can also + * remove points manually using their index. + * + * \ingroup bottleneck_distance + */ +class Naive_pnf { +public: + /** \internal \brief Constructor taking the near distance definition as parameter. */ + Naive_pnf(double r_); + /** \internal \brief A point added will be possibly pulled. */ + void add(int v_point_index); + /** \internal \brief A point manually removed will no longer be possibly pulled. */ + void remove(int v_point_index); + /** \internal \brief Can the point given as parameter be returned ? */ + bool contains(int v_point_index) const; + /** \internal \brief Provide and remove a V point near to the U point given as parameter, null_point_index() if there isn't such a point. */ + int pull_near(int u_point_index); + /** \internal \brief Provide and remove all the V points near to the U point given as parameter. */ + virtual std::shared_ptr< std::list<int> > pull_all_near(int u_point_index); + +private: + double r; + std::pair<int,int> get_v_key(int v_point_index) const; + std::multimap<std::pair<int,int>,int> grid; +}; + +class Cgal_pnf { + + typedef CGAL::Dimension_tag<2> D; + typedef CGAL::Search_traits<double, Internal_point, const double*, CGAL::Construct_coord_iterator, D> Traits; + typedef CGAL::Weighted_Minkowski_distance<Traits> Distance; + typedef CGAL::Orthogonal_incremental_neighbor_search<Traits, Distance> K_neighbor_search; + typedef K_neighbor_search::Tree Kd_tree; + + +public: + /** \internal \brief Constructor taking the near distance definition as parameter. */ + Cgal_pnf(double r_); + /** \internal \brief A point added will be possibly pulled. */ + void add(int v_point_index); + /** \internal \brief A point manually removed will no longer be possibly pulled. */ + void remove(int v_point_index); + /** \internal \brief Can the point given as parameter be returned ? */ + bool contains(int v_point_index) const; + /** \internal \brief Provide a V point near to the U point given as parameter, null_point_index() if there isn't such a point. */ + int pull_near(int u_point_index); + /** \internal \brief Provide and remove all the V points near to the U point given as parameter. */ + virtual std::shared_ptr< std::list<int> > pull_all_near(int u_point_index); + +private: + double r; + std::set<int> contents; + Kd_tree kd_t; +}; + +/** \internal \typedef \brief Planar_neighbors_finder is the used implementation. */ +typedef Cgal_pnf Planar_neighbors_finder; + +inline Naive_pnf::Naive_pnf(double r_) : + r(r_), grid() { } + + +inline std::pair<int,int> Naive_pnf::get_v_key(int v_point_index) const{ + Internal_point v_point = G::get_v_point(v_point_index); + return std::make_pair(static_cast<int>(v_point.x()/r), static_cast<int>(v_point.y()/r)); +} + +inline void Naive_pnf::add(int v_point_index) { + grid.emplace(get_v_key(v_point_index),v_point_index); +} + +inline void Naive_pnf::remove(int v_point_index) { + if(v_point_index != null_point_index()) + for(auto it = grid.find(get_v_key(v_point_index)); it!=grid.end(); it++) + if(it->second==v_point_index){ + grid.erase(it); + return; + } +} + +inline bool Naive_pnf::contains(int v_point_index) const { + if(v_point_index == null_point_index()) + return false; + for(auto it = grid.find(get_v_key(v_point_index)); it!=grid.end(); it++) + if(it->second==v_point_index) + return true; + return false; +} + +inline int Naive_pnf::pull_near(int u_point_index) { + Internal_point u_point = G::get_u_point(u_point_index); + int i0 = static_cast<int>(u_point.x()/r); + int j0 = static_cast<int>(u_point.y()/r); + for(int i = 1; i<= 3; i++) + for(int j = 1; j<= 3; j++) + for(auto it = grid.find(std::make_pair(i0 +(i%3)-1, j0+(j%3)-1)); it!=grid.end(); it++) + if (G::distance(u_point_index, it->second) <= r) { + int tmp = it->second; + grid.erase(it); + return tmp; + } + return null_point_index(); +} + +inline std::shared_ptr< std::list<int> > Naive_pnf::pull_all_near(int u_point_index) { + std::shared_ptr< std::list<int> > all_pull(new std::list<int>); + Internal_point u_point = G::get_u_point(u_point_index); + int i0 = static_cast<int>(u_point.x()/r); + int j0 = static_cast<int>(u_point.y()/r); + for(int i = 1; i<= 3; i++) + for(int j = 1; j<= 3; j++) + for(auto it = grid.find(std::make_pair(i0 +(i%3)-1, j0+(j%3)-1)); it!=grid.end();) + if (G::distance(u_point_index, it->second) <= r) { + all_pull->emplace_back(it->second); + it = grid.erase(it); + } + else it++; + return all_pull; +} + + +/** \internal \brief Constructor taking the near distance definition as parameter. */ +inline Cgal_pnf::Cgal_pnf(double r_) + : r(r_), contents(), kd_t() {} + + +/** \internal \brief A point added will be possibly pulled. */ +inline void Cgal_pnf::add(int v_point_index){ + if(v_point_index == null_point_index()) + return; + contents.insert(v_point_index); + kd_t.insert(G::get_v_point(v_point_index)); +} + +/** \internal \brief A point manually removed will no longer be possibly pulled. */ +inline void Cgal_pnf::remove(int v_point_index){ + if(contains(v_point_index)){ + contents.erase(v_point_index); + kd_t.remove(G::get_v_point(v_point_index)); + } +} + +/** \internal \brief Can the point given as parameter be returned ? */ +inline bool Cgal_pnf::contains(int v_point_index) const{ + if(v_point_index == null_point_index()) + return false; + return contents.count(v_point_index)>0; +} + +/** \internal \brief Provide and remove a V point near to the U point given as parameter, null_point_index() if there isn't such a point. */ +inline int Cgal_pnf::pull_near(int u_point_index){ + Internal_point u_point = G::get_u_point(u_point_index); + std::vector<double> w = {1., 1.}; + K_neighbor_search search(kd_t, u_point, 0., true, Distance(0, 2, w)); + auto it = search.begin(); + if(it==search.end() || G::distance(u_point_index, it->first.point_index) > r) + return null_point_index(); + int tmp = it->first.point_index; + remove(tmp); + return tmp; +} + +inline std::shared_ptr< std::list<int> > Cgal_pnf::pull_all_near(int u_point_index) { + std::shared_ptr< std::list<int> > all_pull(new std::list<int>); + int last_pull = pull_near(u_point_index); + while (last_pull != null_point_index()) { + all_pull->emplace_back(last_pull); + last_pull = pull_near(u_point_index); + } + return all_pull; +} + + +} // namespace Bottleneck_distance + +} // namespace Gudhi + +#endif // SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_ |