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Diffstat (limited to 'src/Bottleneck_distance/include/gudhi/Neighbors_finder.h')
-rw-r--r-- | src/Bottleneck_distance/include/gudhi/Neighbors_finder.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/src/Bottleneck_distance/include/gudhi/Neighbors_finder.h b/src/Bottleneck_distance/include/gudhi/Neighbors_finder.h new file mode 100644 index 00000000..7ad79126 --- /dev/null +++ b/src/Bottleneck_distance/include/gudhi/Neighbors_finder.h @@ -0,0 +1,154 @@ +/* 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_NEIGHBORS_FINDER_H_ +#define SRC_BOTTLENECK_INCLUDE_GUDHI_NEIGHBORS_FINDER_H_ + +#include <unordered_set> +#include <gudhi/Planar_neighbors_finder.h> + +namespace Gudhi { + +namespace Bottleneck_distance { + +/** \internal \brief data structure used to find any point (including projections) in V near to a query point from U + * (which can be a projection). + * + * V points have to be added manually using their index and before the first pull. A neighbor pulled is automatically removed. + * + * \ingroup bottleneck_distance + */ +class Neighbors_finder { +public: + /** \internal \brief Constructor taking the near distance definition as parameter. */ + Neighbors_finder(double r); + /** \internal \brief A point added will be possibly pulled. */ + void add(int v_point_index); + /** \internal \brief Returns 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 Returns and remove all the V points near to the U point given as parameter. */ + std::shared_ptr< std::list<int> > pull_all_near(int u_point_index); + +private: + const double r; + Planar_neighbors_finder planar_neighbors_f; + std::unordered_set<int> projections_f; + void remove(int v_point_index); + bool contains(int v_point_index); +}; + +/** \internal \brief data structure used to find any point (including projections) in V near to a query point from U + * (which can be a projection) in a layered graph layer given as parmeter. + * + * V points have to be added manually using their index and before the first pull. A neighbor pulled is automatically removed. + * + * \ingroup bottleneck_distance + */ +class Layered_neighbors_finder { +public: + /** \internal \brief Constructor taking the near distance definition as parameter. */ + Layered_neighbors_finder(double r); + /** \internal \brief A point added will be possibly pulled. */ + void add(int v_point_index, int vlayer); + /** \internal \brief Returns 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, int vlayer); + /** \internal \brief Returns the number of layers. */ + int vlayers_number() const; + +private: + const double r; + std::vector<std::shared_ptr<Neighbors_finder>> neighbors_finder; +}; + +inline Neighbors_finder::Neighbors_finder(double r) : + r(r), planar_neighbors_f(r), projections_f() { } + +inline void Neighbors_finder::add(int v_point_index) { + if (G::on_the_v_diagonal(v_point_index)) + projections_f.emplace(v_point_index); + else + planar_neighbors_f.add(v_point_index); +} + +inline void Neighbors_finder::remove(int v_point_index) { + if(v_point_index == null_point_index()) + return; + if (G::on_the_v_diagonal(v_point_index)) + projections_f.erase(v_point_index); + else + planar_neighbors_f.remove(v_point_index); +} + +inline bool Neighbors_finder::contains(int v_point_index) { + return planar_neighbors_f.contains(v_point_index) || (projections_f.count(v_point_index)>0); +} + +inline int Neighbors_finder::pull_near(int u_point_index) { + int tmp; + int c = G::corresponding_point_in_v(u_point_index); + if (G::on_the_u_diagonal(u_point_index) && !projections_f.empty()) + //Any pair of projection is at distance 0 + tmp = *projections_f.cbegin(); + else if (contains(c) && (G::distance(u_point_index, c) <= r)) + //Is the query point near to its projection ? + tmp = c; + else + //Is the query point near to a V point in the plane ? + tmp = planar_neighbors_f.pull_near(u_point_index); + remove(tmp); + return tmp; +} + +inline std::shared_ptr< std::list<int> > Neighbors_finder::pull_all_near(int u_point_index) { + std::shared_ptr< std::list<int> > all_pull(planar_neighbors_f.pull_all_near(u_point_index)); + 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; +} + +inline Layered_neighbors_finder::Layered_neighbors_finder(double r) : + r(r), neighbors_finder() { } + +inline void Layered_neighbors_finder::add(int v_point_index, int vlayer) { + for (int l = neighbors_finder.size(); l <= vlayer; l++) + neighbors_finder.emplace_back(std::shared_ptr<Neighbors_finder>(new Neighbors_finder(r))); + neighbors_finder.at(vlayer)->add(v_point_index); +} + +inline int Layered_neighbors_finder::pull_near(int u_point_index, int vlayer) { + if (static_cast<int> (neighbors_finder.size()) <= vlayer) + return null_point_index(); + return neighbors_finder.at(vlayer)->pull_near(u_point_index); +} + +inline int Layered_neighbors_finder::vlayers_number() const { + return static_cast<int>(neighbors_finder.size()); +} + +} // namespace Bottleneck_distance + +} // namespace Gudhi + +#endif // SRC_BOTTLENECK_INCLUDE_GUDHI_NEIGHBORS_FINDER_H_ |