From 8d7329f3e5ad843e553c3c5503cecc28ef2eead6 Mon Sep 17 00:00:00 2001 From: Gard Spreemann Date: Thu, 20 Apr 2017 11:10:45 +0200 Subject: GUDHI 2.0.0 as released by upstream in a tarball. --- include/gudhi/Persistence_graph.h | 188 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 188 insertions(+) create mode 100644 include/gudhi/Persistence_graph.h (limited to 'include/gudhi/Persistence_graph.h') diff --git a/include/gudhi/Persistence_graph.h b/include/gudhi/Persistence_graph.h new file mode 100644 index 00000000..44f4b827 --- /dev/null +++ b/include/gudhi/Persistence_graph.h @@ -0,0 +1,188 @@ +/* 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: Francois Godi + * + * Copyright (C) 2015 INRIA + * + * 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 . + */ + +#ifndef PERSISTENCE_GRAPH_H_ +#define PERSISTENCE_GRAPH_H_ + +#include + +#ifdef GUDHI_USE_TBB +#include +#endif + +#include +#include +#include // for numeric_limits + +namespace Gudhi { + +namespace persistence_diagram { + +/** \internal \brief Structure representing an euclidean bipartite graph containing + * the points from the two persistence diagrams (including the projections). + * + * \ingroup bottleneck_distance + */ +class Persistence_graph { + public: + /** \internal \brief Constructor taking 2 PersistenceDiagrams (concept) as parameters. */ + template + Persistence_graph(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 ? */ + bool on_the_u_diagonal(int u_point_index) const; + /** \internal \brief Is the given point from V the projection of a point in U ? */ + bool on_the_v_diagonal(int v_point_index) const; + /** \internal \brief Given a point from V, returns the corresponding (projection or projector) point in U. */ + int corresponding_point_in_u(int v_point_index) const; + /** \internal \brief Given a point from U, returns the corresponding (projection or projector) point in V. */ + int corresponding_point_in_v(int u_point_index) const; + /** \internal \brief Given a point from U and a point from V, returns the distance between those points. */ + double distance(int u_point_index, int v_point_index) const; + /** \internal \brief Returns size = |U| = |V|. */ + int size() const; + /** \internal \brief Is there as many infinite points (alive components) in both diagrams ? */ + double bottleneck_alive() const; + /** \internal \brief Returns the O(n^2) sorted distances between the points. */ + std::vector sorted_distances() const; + /** \internal \brief Returns an upper bound for the diameter of the convex hull of all non infinite points */ + double diameter_bound() const; + /** \internal \brief Returns the corresponding internal point */ + Internal_point get_u_point(int u_point_index) const; + /** \internal \brief Returns the corresponding internal point */ + Internal_point get_v_point(int v_point_index) const; + + private: + std::vector u; + std::vector v; + double b_alive; +}; + +template +Persistence_graph::Persistence_graph(const Persistence_diagram1 &diag1, + const Persistence_diagram2 &diag2, double e) + : u(), v(), b_alive(0.) { + std::vector u_alive; + std::vector v_alive; + for (auto it = std::begin(diag1); it != std::end(diag1); ++it) { + if (std::get<1>(*it) == std::numeric_limits::infinity()) + u_alive.push_back(std::get<0>(*it)); + else if (std::get<1>(*it) - std::get<0>(*it) > e) + u.push_back(Internal_point(std::get<0>(*it), std::get<1>(*it), u.size())); + } + for (auto it = std::begin(diag2); it != std::end(diag2); ++it) { + if (std::get<1>(*it) == std::numeric_limits::infinity()) + v_alive.push_back(std::get<0>(*it)); + else if (std::get<1>(*it) - std::get<0>(*it) > e) + v.push_back(Internal_point(std::get<0>(*it), std::get<1>(*it), v.size())); + } + if (u.size() < v.size()) + swap(u, v); + std::sort(u_alive.begin(), u_alive.end()); + std::sort(v_alive.begin(), v_alive.end()); + if (u_alive.size() != v_alive.size()) { + b_alive = std::numeric_limits::infinity(); + } else { + for (auto it_u = u_alive.cbegin(), it_v = v_alive.cbegin(); it_u != u_alive.cend(); ++it_u, ++it_v) + b_alive = std::max(b_alive, std::fabs(*it_u - *it_v)); + } +} + +inline bool Persistence_graph::on_the_u_diagonal(int u_point_index) const { + return u_point_index >= static_cast (u.size()); +} + +inline bool Persistence_graph::on_the_v_diagonal(int v_point_index) const { + return v_point_index >= static_cast (v.size()); +} + +inline int Persistence_graph::corresponding_point_in_u(int v_point_index) const { + return on_the_v_diagonal(v_point_index) ? + v_point_index - static_cast (v.size()) : v_point_index + static_cast (u.size()); +} + +inline int Persistence_graph::corresponding_point_in_v(int u_point_index) const { + return on_the_u_diagonal(u_point_index) ? + u_point_index - static_cast (u.size()) : u_point_index + static_cast (v.size()); +} + +inline double Persistence_graph::distance(int u_point_index, int v_point_index) const { + 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 Persistence_graph::size() const { + return static_cast (u.size() + v.size()); +} + +inline double Persistence_graph::bottleneck_alive() const { + return b_alive; +} + +inline std::vector Persistence_graph::sorted_distances() const { + std::vector distances; + distances.push_back(0.); // for empty diagrams + for (int u_point_index = 0; u_point_index < size(); ++u_point_index) { + distances.push_back(distance(u_point_index, corresponding_point_in_v(u_point_index))); + for (int v_point_index = 0; v_point_index < size(); ++v_point_index) + distances.push_back(distance(u_point_index, v_point_index)); + } +#ifdef GUDHI_USE_TBB + tbb::parallel_sort(distances.begin(), distances.end()); +#else + std::sort(distances.begin(), distances.end()); +#endif + return distances; +} + +inline Internal_point Persistence_graph::get_u_point(int u_point_index) const { + 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 Persistence_graph::get_v_point(int v_point_index) const { + 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 Persistence_graph::diameter_bound() const { + 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 persistence_diagram + +} // namespace Gudhi + +#endif // PERSISTENCE_GRAPH_H_ -- cgit v1.2.3