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Diffstat (limited to 'trunk/src/Alpha_complex/example/Alpha_complex_from_points.cpp')
-rw-r--r-- | trunk/src/Alpha_complex/example/Alpha_complex_from_points.cpp | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/trunk/src/Alpha_complex/example/Alpha_complex_from_points.cpp b/trunk/src/Alpha_complex/example/Alpha_complex_from_points.cpp new file mode 100644 index 00000000..c19f7cc8 --- /dev/null +++ b/trunk/src/Alpha_complex/example/Alpha_complex_from_points.cpp @@ -0,0 +1,68 @@ +#include <gudhi/Alpha_complex.h> +// to construct a simplex_tree from alpha complex +#include <gudhi/Simplex_tree.h> + +#include <CGAL/Epick_d.h> + +#include <iostream> +#include <string> +#include <vector> +#include <limits> // for numeric limits + +using Kernel = CGAL::Epick_d< CGAL::Dimension_tag<2> >; +using Point = Kernel::Point_d; +using Vector_of_points = std::vector<Point>; + +void usage(int nbArgs, char * const progName) { + std::cerr << "Error: Number of arguments (" << nbArgs << ") is not correct\n"; + std::cerr << "Usage: " << progName << " [alpha_square_max_value]\n"; + std::cerr << " i.e.: " << progName << " 60.0\n"; + exit(-1); // ----- >> +} + +int main(int argc, char **argv) { + if ((argc != 1) && (argc != 2)) usage(argc, (argv[0] - 1)); + + // Delaunay complex if alpha_square_max_value is not given by the user. + double alpha_square_max_value {std::numeric_limits<double>::infinity()}; + if (argc == 2) + alpha_square_max_value = atof(argv[1]); + + // ---------------------------------------------------------------------------- + // Init of a list of points + // ---------------------------------------------------------------------------- + Vector_of_points points; + points.push_back(Point(1.0, 1.0)); + points.push_back(Point(7.0, 0.0)); + points.push_back(Point(4.0, 6.0)); + points.push_back(Point(9.0, 6.0)); + points.push_back(Point(0.0, 14.0)); + points.push_back(Point(2.0, 19.0)); + points.push_back(Point(9.0, 17.0)); + + // ---------------------------------------------------------------------------- + // Init of an alpha complex from the list of points + // ---------------------------------------------------------------------------- + Gudhi::alpha_complex::Alpha_complex<Kernel> alpha_complex_from_points(points); + + Gudhi::Simplex_tree<> simplex; + if (alpha_complex_from_points.create_complex(simplex, alpha_square_max_value)) { + // ---------------------------------------------------------------------------- + // Display information about the alpha complex + // ---------------------------------------------------------------------------- + std::cout << "Alpha complex is of dimension " << simplex.dimension() << + " - " << simplex.num_simplices() << " simplices - " << + simplex.num_vertices() << " vertices." << std::endl; + + std::cout << "Iterator on alpha complex simplices in the filtration order, with [filtration value]:" << std::endl; + for (auto f_simplex : simplex.filtration_simplex_range()) { + std::cout << " ( "; + for (auto vertex : simplex.simplex_vertex_range(f_simplex)) { + std::cout << vertex << " "; + } + std::cout << ") -> " << "[" << simplex.filtration(f_simplex) << "] "; + std::cout << std::endl; + } + } + return 0; +} |