From c524232f734de875d69e2f190f01a6c976024368 Mon Sep 17 00:00:00 2001 From: Gard Spreemann Date: Thu, 14 Jun 2018 20:39:01 +0200 Subject: GUDHI 2.2.0 as released by upstream in a tarball. --- utilities/Cech_complex/cech_persistence.cpp | 136 ++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 utilities/Cech_complex/cech_persistence.cpp (limited to 'utilities/Cech_complex/cech_persistence.cpp') diff --git a/utilities/Cech_complex/cech_persistence.cpp b/utilities/Cech_complex/cech_persistence.cpp new file mode 100644 index 00000000..abd9dbcd --- /dev/null +++ b/utilities/Cech_complex/cech_persistence.cpp @@ -0,0 +1,136 @@ +/* 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 . + */ + +#include +#include +#include +#include +#include + +#include + +#include +#include +#include // infinity + +// Types definition +using Simplex_tree = Gudhi::Simplex_tree; +using Filtration_value = Simplex_tree::Filtration_value; +using Point = std::vector; +using Point_cloud = std::vector; +using Points_off_reader = Gudhi::Points_off_reader; +using Cech_complex = Gudhi::cech_complex::Cech_complex; +using Field_Zp = Gudhi::persistent_cohomology::Field_Zp; +using Persistent_cohomology = Gudhi::persistent_cohomology::Persistent_cohomology; + +void program_options(int argc, char* argv[], std::string& off_file_points, std::string& filediag, + Filtration_value& max_radius, int& dim_max, int& p, Filtration_value& min_persistence); + +int main(int argc, char* argv[]) { + std::string off_file_points; + std::string filediag; + Filtration_value max_radius; + int dim_max; + int p; + Filtration_value min_persistence; + + program_options(argc, argv, off_file_points, filediag, max_radius, dim_max, p, min_persistence); + + Points_off_reader off_reader(off_file_points); + Cech_complex cech_complex_from_file(off_reader.get_point_cloud(), max_radius); + + // Construct the Cech complex in a Simplex Tree + Simplex_tree simplex_tree; + + cech_complex_from_file.create_complex(simplex_tree, dim_max); + std::cout << "The complex contains " << simplex_tree.num_simplices() << " simplices \n"; + std::cout << " and has dimension " << simplex_tree.dimension() << " \n"; + + // Sort the simplices in the order of the filtration + simplex_tree.initialize_filtration(); + + // Compute the persistence diagram of the complex + Persistent_cohomology pcoh(simplex_tree); + // initializes the coefficient field for homology + pcoh.init_coefficients(p); + + pcoh.compute_persistent_cohomology(min_persistence); + + // Output the diagram in filediag + if (filediag.empty()) { + pcoh.output_diagram(); + } else { + std::ofstream out(filediag); + pcoh.output_diagram(out); + out.close(); + } + + return 0; +} + +void program_options(int argc, char* argv[], std::string& off_file_points, std::string& filediag, + Filtration_value& max_radius, int& dim_max, int& p, Filtration_value& min_persistence) { + namespace po = boost::program_options; + po::options_description hidden("Hidden options"); + hidden.add_options()("input-file", po::value(&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")( + "output-file,o", po::value(&filediag)->default_value(std::string()), + "Name of file in which the persistence diagram is written. Default print in std::cout")( + "max-radius,r", + po::value(&max_radius)->default_value(std::numeric_limits::infinity()), + "Maximal length of an edge for the Cech complex construction.")( + "cpx-dimension,d", po::value(&dim_max)->default_value(1), + "Maximal dimension of the Cech complex we want to compute.")( + "field-charac,p", po::value(&p)->default_value(11), + "Characteristic p of the coefficient field Z/pZ for computing homology.")( + "min-persistence,m", po::value(&min_persistence), + "Minimal lifetime of homology feature to be recorded. Default is 0. Enter a negative value to see zero length " + "intervals"); + + 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 << "Compute the persistent homology with coefficient field Z/pZ \n"; + std::cout << "of a Cech complex defined on a set of input points.\n \n"; + std::cout << "The output diagram contains one bar per line, written with the convention: \n"; + std::cout << " p dim b d \n"; + std::cout << "where dim is the dimension of the homological feature,\n"; + std::cout << "b and d are respectively the birth and death of the feature and \n"; + std::cout << "p is the characteristic of the field Z/pZ used for homology coefficients." << std::endl << std::endl; + + std::cout << "Usage: " << argv[0] << " [options] input-file" << std::endl << std::endl; + std::cout << visible << std::endl; + std::abort(); + } +} -- cgit v1.2.3