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Diffstat (limited to 'src/Bottleneck_distance/include/gudhi/Persistence_diagrams_graph.h')
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diff --git a/src/Bottleneck_distance/include/gudhi/Persistence_diagrams_graph.h b/src/Bottleneck_distance/include/gudhi/Persistence_diagrams_graph.h new file mode 100644 index 00000000..e31b2dae --- /dev/null +++ b/src/Bottleneck_distance/include/gudhi/Persistence_diagrams_graph.h @@ -0,0 +1,169 @@ +/* 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_PERSISTENCE_DIAGRAMS_GRAPH_H_ +#define SRC_BOTTLENECK_INCLUDE_GUDHI_PERSISTENCE_DIAGRAMS_GRAPH_H_ + +#include <vector> +#include <set> +#include <cmath> +#include <utility> +#include <algorithm> +#include <math.h> +#include <memory> +#include <gudhi/Internal_point.h> + +namespace Gudhi { + +namespace Bottleneck_distance { + + +/** \internal \brief Structure representing an euclidean bipartite graph containing + * the points from the two persistence diagrams (including the projections). + * + * \ingroup bottleneck_distance + */ +class Persistence_diagrams_graph { +public: + /** \internal \brief Initializer taking 2 Point (concept) ranges as parameters. */ + template<typename Persistence_diagram1, typename Persistence_diagram2> + static void initialize(const Persistence_diagram1& diag1, const Persistence_diagram2& diag2, double e); + /** \internal \brief Is the given point from U the projection of a point in V ? */ + static bool on_the_u_diagonal(int u_point_index); + /** \internal \brief Is the given point from V the projection of a point in U ? */ + static bool on_the_v_diagonal(int v_point_index); + /** \internal \brief Given a point from V, returns the corresponding (projection or projector) point in U. */ + static int corresponding_point_in_u(int v_point_index); + /** \internal \brief Given a point from U, returns the corresponding (projection or projector) point in V. */ + static int corresponding_point_in_v(int u_point_index); + /** \internal \brief Given a point from U and a point from V, returns the distance between those points. */ + static double distance(int u_point_index, int v_point_index); + /** \internal \brief Returns size = |U| = |V|. */ + static int size(); + /** \internal \brief Returns the O(n^2) sorted distances between the points. */ + static std::shared_ptr< std::vector<double> > sorted_distances(); + /** \internal \brief Returns an upper bound of the diameter of the convex hull */ + static double diameter(); + +private: + static std::vector<Internal_point> u; + static std::vector<Internal_point> v; + static Internal_point get_u_point(int u_point_index); + static Internal_point get_v_point(int v_point_index); + + friend class Naive_pnf; + friend class Cgal_pnf; +}; + +/** \internal \typedef \brief Shorter alias */ +typedef Persistence_diagrams_graph G; + +// static initialization +std::vector<Internal_point> G::u = [] {return std::vector<Internal_point>();}(); +std::vector<Internal_point> G::v = [] {return std::vector<Internal_point>();}(); + +template<typename Persistence_diagram1, typename Persistence_diagram2> +inline void G::initialize(const Persistence_diagram1 &diag1, + const Persistence_diagram2 &diag2, double e){ + u.clear(); + v.clear(); + for (auto it = diag1.cbegin(); it != diag1.cend(); ++it) + if (it->second - it->first > e) + u.push_back(Internal_point(it->first, it->second, u.size())); + for (auto it = diag2.cbegin(); it != diag2.cend(); ++it) + if (it->second - it->first > e) + v.push_back(Internal_point(it->first, it->second, v.size())); + if (u.size() < v.size()) + swap(u, v); +} + +inline bool G::on_the_u_diagonal(int u_point_index) { + return u_point_index >= static_cast<int> (u.size()); +} + +inline bool G::on_the_v_diagonal(int v_point_index) { + return v_point_index >= static_cast<int> (v.size()); +} + +inline int G::corresponding_point_in_u(int v_point_index) { + return on_the_v_diagonal(v_point_index) ? + v_point_index - static_cast<int> (v.size()) : v_point_index + static_cast<int> (u.size()); +} + +inline int G::corresponding_point_in_v(int u_point_index) { + return on_the_u_diagonal(u_point_index) ? + u_point_index - static_cast<int> (u.size()) : u_point_index + static_cast<int> (v.size()); +} + +inline double G::distance(int u_point_index, int v_point_index) { + if (on_the_u_diagonal(u_point_index) && on_the_v_diagonal(v_point_index)) + return 0; + Internal_point p_u = get_u_point(u_point_index); + Internal_point p_v = get_v_point(v_point_index); + return std::max(std::fabs(p_u.x() - p_v.x()), std::fabs(p_u.y() - p_v.y())); +} + +inline int G::size() { + return static_cast<int> (u.size() + v.size()); +} + +inline std::shared_ptr< std::vector<double> > G::sorted_distances() { + // could be optimized + std::set<double> sorted_distances; + sorted_distances.emplace(0.); + for (int u_point_index = 0; u_point_index < size(); ++u_point_index) + for (int v_point_index = 0; v_point_index < size(); ++v_point_index) + sorted_distances.emplace(distance(u_point_index, v_point_index)); + std::shared_ptr< std::vector<double> > sd_up(new std::vector<double>(sorted_distances.cbegin(), sorted_distances.cend())); + return sd_up; +} + +inline Internal_point G::get_u_point(int u_point_index) { + if (!on_the_u_diagonal(u_point_index)) + return u.at(u_point_index); + Internal_point projector = v.at(corresponding_point_in_v(u_point_index)); + double m = (projector.x() + projector.y()) / 2; + return Internal_point(m,m,u_point_index); +} + +inline Internal_point G::get_v_point(int v_point_index) { + if (!on_the_v_diagonal(v_point_index)) + return v.at(v_point_index); + Internal_point projector = u.at(corresponding_point_in_u(v_point_index)); + double m = (projector.x() + projector.y()) / 2; + return Internal_point(m,m,v_point_index); +} + +inline double G::diameter() { + double max = 0.; + for(auto it = u.cbegin(); it != u.cend(); it++) + max = std::max(max,it->y()); + for(auto it = v.cbegin(); it != v.cend(); it++) + max = std::max(max,it->y()); + return max; +} + +} // namespace Bottleneck_distance + +} // namespace Gudhi + +#endif // SRC_BOTTLENECK_INCLUDE_GUDHI_PERSISTENCE_DIAGRAMS_GRAPH_H_ |