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diff --git a/trunk/src/Witness_complex/example/generators.h b/trunk/src/Witness_complex/example/generators.h new file mode 100644 index 00000000..7df43db5 --- /dev/null +++ b/trunk/src/Witness_complex/example/generators.h @@ -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): Siargey Kachanovich + * + * Copyright (C) 2015 INRIA Sophia Antipolis-Méditerranée (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 EXAMPLE_WITNESS_COMPLEX_GENERATORS_H_ +#define EXAMPLE_WITNESS_COMPLEX_GENERATORS_H_ + +#include <CGAL/Epick_d.h> +#include <CGAL/point_generators_d.h> +#include <CGAL/Random.h> + +#include <fstream> +#include <string> +#include <vector> +#include <cmath> + +using K = CGAL::Epick_d<CGAL::Dynamic_dimension_tag>; +using FT = K::FT; +using Point_d = K::Point_d; +using Point_Vector = std::vector<Point_d>; +using Random_cube_iterator = CGAL::Random_points_in_cube_d<Point_d>; +using Random_point_iterator = CGAL::Random_points_in_ball_d<Point_d>; + +/** + * \brief Rock age method of reading off file + * + */ +inline void +off_reader_cust(std::string file_name, std::vector<Point_d> & points) { + std::ifstream in_file(file_name.c_str(), std::ios::in); + if (!in_file.is_open()) { + std::cerr << "Unable to open file " << file_name << std::endl; + return; + } + std::string line; + double x; + // Line OFF. No need in it + if (!getline(in_file, line)) { + std::cerr << "No line OFF\n"; + return; + } + // Line with 3 numbers. No need + if (!getline(in_file, line)) { + std::cerr << "No line with 3 numbers\n"; + return; + } + // Reading points + while (getline(in_file, line)) { + std::vector< double > point; + std::istringstream iss(line); + while (iss >> x) { + point.push_back(x); + } + points.push_back(Point_d(point)); + } + in_file.close(); +} + +/** + * \brief Customized version of read_points + * which takes into account a possible nbP first line + * + */ +inline void +read_points_cust(std::string file_name, Point_Vector & points) { + std::ifstream in_file(file_name.c_str(), std::ios::in); + if (!in_file.is_open()) { + std::cerr << "Unable to open file " << file_name << std::endl; + return; + } + std::string line; + double x; + while (getline(in_file, line)) { + std::vector< double > point; + std::istringstream iss(line); + while (iss >> x) { + point.push_back(x); + } + Point_d p(point.begin(), point.end()); + if (point.size() != 1) + points.push_back(p); + } + in_file.close(); +} + +/** \brief Generate points on a grid in a cube of side 2 + * having {+-1}^D as vertices and insert them in W. + * The grid has "width" points on each side. + * If torus is true then it is supposed that the cube represents + * a flat torus, hence the opposite borders are associated. + * The points on border in this case are not placed twice. + */ +void generate_points_grid(Point_Vector& W, int width, int D, bool torus) { + int nb_points = 1; + for (int i = 0; i < D; ++i) + nb_points *= width; + for (int i = 0; i < nb_points; ++i) { + std::vector<double> point; + int cell_i = i; + for (int l = 0; l < D; ++l) { + if (torus) + point.push_back(-1 + (2.0 / (width - 1))*(cell_i % width)); + else + point.push_back(-1 + (2.0 / width)*(cell_i % width)); + // attention: the bottom and the right are covered too! + cell_i /= width; + } + W.push_back(point); + } +} + +/** \brief Generate nbP points uniformly in a cube of side 2 + * having {+-1}^dim as its vertices and insert them in W. + */ +void generate_points_random_box(Point_Vector& W, int nbP, int dim) { + Random_cube_iterator rp(dim, 1.0); + for (int i = 0; i < nbP; i++) { + W.push_back(*rp++); + } +} + +/** \brief Generate nbP points uniformly on a (dim-1)-sphere + * and insert them in W. + */ +void generate_points_sphere(Point_Vector& W, int nbP, int dim) { + CGAL::Random_points_on_sphere_d<Point_d> rp(dim, 1); + for (int i = 0; i < nbP; i++) + W.push_back(*rp++); +} + +/** \brief Generate nbP points on a (flat) d-torus embedded in R^{2d} + * + */ +void generate_points_torus(Point_Vector& W, int nbP, int dim) { + CGAL::Random rand; + const double pi = std::acos(-1); + for (int i = 0; i < nbP; i++) { + std::vector<FT> point; + for (int j = 0; j < dim; j++) { + double alpha = rand.uniform_real(static_cast<double>(0), 2*pi); + point.push_back(sin(alpha)); + point.push_back(cos(alpha)); + } + W.push_back(Point_d(point)); + } +} + +#endif // EXAMPLE_WITNESS_COMPLEX_GENERATORS_H_ |