diff options
Diffstat (limited to 'example/Cech_complex')
-rw-r--r-- | example/Cech_complex/CMakeLists.txt | 16 | ||||
-rw-r--r-- | example/Cech_complex/cech_complex_example_from_points.cpp | 54 | ||||
-rw-r--r-- | example/Cech_complex/cech_complex_example_from_points_for_doc.txt | 31 | ||||
-rw-r--r-- | example/Cech_complex/cech_complex_step_by_step.cpp | 166 |
4 files changed, 267 insertions, 0 deletions
diff --git a/example/Cech_complex/CMakeLists.txt b/example/Cech_complex/CMakeLists.txt new file mode 100644 index 00000000..ab391215 --- /dev/null +++ b/example/Cech_complex/CMakeLists.txt @@ -0,0 +1,16 @@ +cmake_minimum_required(VERSION 2.6) +project(Cech_complex_examples) + +add_executable ( Cech_complex_example_step_by_step cech_complex_step_by_step.cpp ) +target_link_libraries(Cech_complex_example_step_by_step ${Boost_PROGRAM_OPTIONS_LIBRARY}) +if (TBB_FOUND) + target_link_libraries(Cech_complex_example_step_by_step ${TBB_LIBRARIES}) +endif() +add_test(NAME Cech_complex_utility_from_rips_on_tore_3D COMMAND $<TARGET_FILE:Cech_complex_example_step_by_step> + "${CMAKE_SOURCE_DIR}/data/points/tore3D_300.off" "-r" "0.25" "-d" "3") + +add_executable ( Cech_complex_example_from_points cech_complex_example_from_points.cpp) +if (TBB_FOUND) + target_link_libraries(Cech_complex_example_from_points ${TBB_LIBRARIES}) +endif() +add_test(NAME Cech_complex_example_from_points COMMAND $<TARGET_FILE:Cech_complex_example_from_points>) diff --git a/example/Cech_complex/cech_complex_example_from_points.cpp b/example/Cech_complex/cech_complex_example_from_points.cpp new file mode 100644 index 00000000..3cc5a4df --- /dev/null +++ b/example/Cech_complex/cech_complex_example_from_points.cpp @@ -0,0 +1,54 @@ +#include <gudhi/Cech_complex.h> +#include <gudhi/Simplex_tree.h> + +#include <iostream> +#include <string> +#include <vector> +#include <array> + +int main() { + // Type definitions + using Point_cloud = std::vector<std::array<double, 2>>; + using Simplex_tree = Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_fast_persistence>; + using Filtration_value = Simplex_tree::Filtration_value; + using Cech_complex = Gudhi::cech_complex::Cech_complex<Simplex_tree, Point_cloud>; + + Point_cloud points; + points.push_back({1., 0.}); // 0 + points.push_back({0., 1.}); // 1 + points.push_back({2., 1.}); // 2 + points.push_back({3., 2.}); // 3 + points.push_back({0., 3.}); // 4 + points.push_back({3. + std::sqrt(3.), 3.}); // 5 + points.push_back({1., 4.}); // 6 + points.push_back({3., 4.}); // 7 + points.push_back({2., 4. + std::sqrt(3.)}); // 8 + points.push_back({0., 4.}); // 9 + points.push_back({-0.5, 2.}); // 10 + + // ---------------------------------------------------------------------------- + // Init of a Cech complex from points + // ---------------------------------------------------------------------------- + Filtration_value max_radius = 1.; + Cech_complex cech_complex_from_points(points, max_radius); + + Simplex_tree stree; + cech_complex_from_points.create_complex(stree, 2); + // ---------------------------------------------------------------------------- + // Display information about the one skeleton Cech complex + // ---------------------------------------------------------------------------- + std::cout << "Cech complex is of dimension " << stree.dimension() << " - " << stree.num_simplices() << " simplices - " + << stree.num_vertices() << " vertices." << std::endl; + + std::cout << "Iterator on Cech complex simplices in the filtration order, with [filtration value]:" << std::endl; + for (auto f_simplex : stree.filtration_simplex_range()) { + std::cout << " ( "; + for (auto vertex : stree.simplex_vertex_range(f_simplex)) { + std::cout << vertex << " "; + } + std::cout << ") -> " + << "[" << stree.filtration(f_simplex) << "] "; + std::cout << std::endl; + } + return 0; +} diff --git a/example/Cech_complex/cech_complex_example_from_points_for_doc.txt b/example/Cech_complex/cech_complex_example_from_points_for_doc.txt new file mode 100644 index 00000000..be0afc76 --- /dev/null +++ b/example/Cech_complex/cech_complex_example_from_points_for_doc.txt @@ -0,0 +1,31 @@ +Iterator on Cech complex simplices in the filtration order, with [filtration value]: + ( 0 ) -> [0] + ( 1 ) -> [0] + ( 2 ) -> [0] + ( 3 ) -> [0] + ( 4 ) -> [0] + ( 5 ) -> [0] + ( 6 ) -> [0] + ( 7 ) -> [0] + ( 8 ) -> [0] + ( 9 ) -> [0] + ( 10 ) -> [0] + ( 9 4 ) -> [0.5] + ( 9 6 ) -> [0.5] + ( 10 1 ) -> [0.559017] + ( 10 4 ) -> [0.559017] + ( 1 0 ) -> [0.707107] + ( 2 0 ) -> [0.707107] + ( 3 2 ) -> [0.707107] + ( 6 4 ) -> [0.707107] + ( 9 6 4 ) -> [0.707107] + ( 2 1 ) -> [1] + ( 2 1 0 ) -> [1] + ( 4 1 ) -> [1] + ( 5 3 ) -> [1] + ( 7 3 ) -> [1] + ( 7 5 ) -> [1] + ( 7 6 ) -> [1] + ( 8 6 ) -> [1] + ( 8 7 ) -> [1] + ( 10 4 1 ) -> [1] diff --git a/example/Cech_complex/cech_complex_step_by_step.cpp b/example/Cech_complex/cech_complex_step_by_step.cpp new file mode 100644 index 00000000..d2dc8b65 --- /dev/null +++ b/example/Cech_complex/cech_complex_step_by_step.cpp @@ -0,0 +1,166 @@ +/* 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): Vincent Rouvreau + * + * Copyright (C) 2018 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 <http://www.gnu.org/licenses/>. + */ + +#include <gudhi/graph_simplicial_complex.h> +#include <gudhi/distance_functions.h> +#include <gudhi/Simplex_tree.h> +#include <gudhi/Points_off_io.h> + +#include <gudhi/Miniball.hpp> + +#include <boost/program_options.hpp> + +#include <string> +#include <vector> +#include <limits> // infinity +#include <utility> // for pair +#include <map> + +// ---------------------------------------------------------------------------- +// rips_persistence_step_by_step is an example of each step that is required to +// build a Rips over a Simplex_tree. Please refer to rips_persistence to see +// how to do the same thing with the Rips_complex wrapper for less detailed +// steps. +// ---------------------------------------------------------------------------- + +// Types definition +using Simplex_tree = Gudhi::Simplex_tree<>; +using Simplex_handle = Simplex_tree::Simplex_handle; +using Filtration_value = Simplex_tree::Filtration_value; +using Point = std::vector<double>; +using Points_off_reader = Gudhi::Points_off_reader<Point>; +using Proximity_graph = Gudhi::Proximity_graph<Simplex_tree>; + +class Cech_blocker { + private: + using Point_cloud = std::vector<Point>; + using Point_iterator = Point_cloud::const_iterator; + using Coordinate_iterator = Point::const_iterator; + using Min_sphere = Gudhi::Miniball::Miniball<Gudhi::Miniball::CoordAccessor<Point_iterator, Coordinate_iterator>>; + + public: + bool operator()(Simplex_handle sh) { + std::vector<Point> points; + for (auto vertex : simplex_tree_.simplex_vertex_range(sh)) { + points.push_back(point_cloud_[vertex]); +#ifdef DEBUG_TRACES + std::cout << "#(" << vertex << ")#"; +#endif // DEBUG_TRACES + } + Filtration_value radius = Gudhi::Minimal_enclosing_ball_radius()(points); +#ifdef DEBUG_TRACES + std::cout << "radius = " << radius << " - " << (radius > max_radius_) << std::endl; +#endif // DEBUG_TRACES + simplex_tree_.assign_filtration(sh, radius); + return (radius > max_radius_); + } + Cech_blocker(Simplex_tree& simplex_tree, Filtration_value max_radius, const std::vector<Point>& point_cloud) + : simplex_tree_(simplex_tree), max_radius_(max_radius), point_cloud_(point_cloud) { + dimension_ = point_cloud_[0].size(); + } + + private: + Simplex_tree simplex_tree_; + Filtration_value max_radius_; + std::vector<Point> point_cloud_; + int dimension_; +}; + +void program_options(int argc, char* argv[], std::string& off_file_points, Filtration_value& max_radius, int& dim_max); + +int main(int argc, char* argv[]) { + std::string off_file_points; + Filtration_value max_radius; + int dim_max; + + program_options(argc, argv, off_file_points, max_radius, dim_max); + + // Extract the points from the file filepoints + Points_off_reader off_reader(off_file_points); + + // Compute the proximity graph of the points + Proximity_graph prox_graph = Gudhi::compute_proximity_graph<Simplex_tree>(off_reader.get_point_cloud(), max_radius, + Gudhi::Minimal_enclosing_ball_radius()); + + // Construct the Rips complex in a Simplex Tree + Simplex_tree st; + // insert the proximity graph in the simplex tree + st.insert_graph(prox_graph); + // expand the graph until dimension dim_max + st.expansion_with_blockers(dim_max, Cech_blocker(st, max_radius, off_reader.get_point_cloud())); + + std::cout << "The complex contains " << st.num_simplices() << " simplices \n"; + std::cout << " and has dimension " << st.dimension() << " \n"; + + // Sort the simplices in the order of the filtration + st.initialize_filtration(); + +#if DEBUG_TRACES + std::cout << "********************************************************************\n"; + std::cout << "* The complex contains " << st.num_simplices() << " simplices - dimension=" << st.dimension() << "\n"; + std::cout << "* Iterator on Simplices in the filtration, with [filtration value]:\n"; + for (auto f_simplex : st.filtration_simplex_range()) { + std::cout << " " + << "[" << st.filtration(f_simplex) << "] "; + for (auto vertex : st.simplex_vertex_range(f_simplex)) { + std::cout << static_cast<int>(vertex) << " "; + } + std::cout << std::endl; + } +#endif // DEBUG_TRACES + + return 0; +} + +void program_options(int argc, char* argv[], std::string& off_file_points, Filtration_value& max_radius, int& dim_max) { + namespace po = boost::program_options; + po::options_description hidden("Hidden options"); + hidden.add_options()("input-file", po::value<std::string>(&off_file_points), + "Name of an OFF file containing a point set.\n"); + + po::options_description visible("Allowed options", 100); + visible.add_options()("help,h", "produce help message")( + "max-radius,r", + po::value<Filtration_value>(&max_radius)->default_value(std::numeric_limits<Filtration_value>::infinity()), + "Maximal length of an edge for the Rips complex construction.")( + "cpx-dimension,d", po::value<int>(&dim_max)->default_value(1), + "Maximal dimension of the Rips complex we want to compute."); + + po::positional_options_description pos; + pos.add("input-file", 1); + + po::options_description all; + all.add(visible).add(hidden); + + po::variables_map vm; + po::store(po::command_line_parser(argc, argv).options(all).positional(pos).run(), vm); + po::notify(vm); + + if (vm.count("help") || !vm.count("input-file")) { + std::cout << std::endl; + std::cout << "Construct a Cech complex defined on a set of input points.\n \n"; + + std::cout << "Usage: " << argv[0] << " [options] input-file" << std::endl << std::endl; + std::cout << visible << std::endl; + std::abort(); + } +} |