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Diffstat (limited to 'trunk/src/Witness_complex/example/example_witness_complex_sphere.cpp')
-rw-r--r-- | trunk/src/Witness_complex/example/example_witness_complex_sphere.cpp | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/trunk/src/Witness_complex/example/example_witness_complex_sphere.cpp b/trunk/src/Witness_complex/example/example_witness_complex_sphere.cpp new file mode 100644 index 00000000..124fd99b --- /dev/null +++ b/trunk/src/Witness_complex/example/example_witness_complex_sphere.cpp @@ -0,0 +1,92 @@ +/* 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): Siargey Kachanovich + * + * Copyright (C) 2016 INRIA (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/>. + */ + +#define BOOST_PARAMETER_MAX_ARITY 12 + +#include <gudhi/Simplex_tree.h> +#include <gudhi/Euclidean_witness_complex.h> +#include <gudhi/pick_n_random_points.h> +#include <gudhi/reader_utils.h> + +#include <CGAL/Epick_d.h> + +#include <iostream> +#include <fstream> +#include <ctime> +#include <utility> +#include <string> +#include <vector> + +#include "generators.h" + +/** Write a gnuplot readable file. + * Data range is a random access range of pairs (arg, value) + */ +template < typename Data_range > +void write_data(Data_range & data, std::string filename) { + std::ofstream ofs(filename, std::ofstream::out); + for (auto entry : data) + ofs << entry.first << ", " << entry.second << "\n"; + ofs.close(); +} + +int main(int argc, char * const argv[]) { + using Kernel = CGAL::Epick_d<CGAL::Dynamic_dimension_tag>; + using Witness_complex = Gudhi::witness_complex::Euclidean_witness_complex<Kernel>; + + if (argc != 2) { + std::cerr << "Usage: " << argv[0] + << " number_of_landmarks \n"; + return 0; + } + + int number_of_landmarks = atoi(argv[1]); + + std::vector< std::pair<int, double> > l_time; + + // Generate points + for (int nbP = 500; nbP < 10000; nbP += 500) { + clock_t start, end; + // Construct the Simplex Tree + Gudhi::Simplex_tree<> simplex_tree; + Point_Vector point_vector, landmarks; + generate_points_sphere(point_vector, nbP, 4); + std::cout << "Successfully generated " << point_vector.size() << " points.\n"; + std::cout << "Ambient dimension is " << point_vector[0].size() << ".\n"; + + // Choose landmarks + start = clock(); + Gudhi::subsampling::pick_n_random_points(point_vector, number_of_landmarks, std::back_inserter(landmarks)); + + // Compute witness complex + Witness_complex witness_complex(landmarks, + point_vector); + witness_complex.create_complex(simplex_tree, 0); + end = clock(); + double time = static_cast<double>(end - start) / CLOCKS_PER_SEC; + std::cout << "Witness complex for " << number_of_landmarks << " landmarks took " + << time << " s. \n"; + std::cout << "Number of simplices is: " << simplex_tree.num_simplices() << "\n"; + l_time.push_back(std::make_pair(nbP, time)); + } + write_data(l_time, "w_time.dat"); +} |