diff options
Diffstat (limited to 'src/Rips_complex/example/example_one_skeleton_rips_from_distance_matrix.cpp')
-rw-r--r-- | src/Rips_complex/example/example_one_skeleton_rips_from_distance_matrix.cpp | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/src/Rips_complex/example/example_one_skeleton_rips_from_distance_matrix.cpp b/src/Rips_complex/example/example_one_skeleton_rips_from_distance_matrix.cpp new file mode 100644 index 00000000..54fa3aa1 --- /dev/null +++ b/src/Rips_complex/example/example_one_skeleton_rips_from_distance_matrix.cpp @@ -0,0 +1,68 @@ +#include <gudhi/Rips_complex.h> +// to construct a simplex_tree from rips complex +#include <gudhi/Simplex_tree.h> +#include <gudhi/distance_functions.h> + +#include <iostream> +#include <string> +#include <limits> // for std::numeric_limits + +void usage(int nbArgs, char * const progName) { + std::cerr << "Error: Number of arguments (" << nbArgs << ") is not correct\n"; + std::cerr << "Usage: " << progName << " threshold\n"; + std::cerr << " i.e.: " << progName << " 12.0\n"; + exit(-1); // ----- >> +} + +int main(int argc, char **argv) { + if (argc != 2) usage(argc, argv[0]); + + double threshold = atof(argv[1]); + + // Type definitions + using Simplex_tree = Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_fast_persistence>; + using Filtration_value = Simplex_tree::Filtration_value; + using Rips_complex = Gudhi::rips_complex::Rips_complex<Filtration_value>; + using Distance_matrix = std::vector<std::vector<Filtration_value>>; + + // User defined distance matrix is: + // | 0 0.94 0.77 0.99 0.11 | + // | 0.94 0 0.26 0.99 0.39 | + // | 0.77 0.26 0 0.28 0.97 | + // | 0.99 0.99 0.28 0 0.30 | + // | 0.11 0.39 0.97 0.30 0 | + + Distance_matrix distances; + distances.push_back({}); + distances.push_back({0.94}); + distances.push_back({0.77, 0.26}); + distances.push_back({0.99, 0.99, 0.28}); + distances.push_back({0.11, 0.39, 0.97, 0.30}); + + // ---------------------------------------------------------------------------- + // Init of a rips complex from points + // ---------------------------------------------------------------------------- + Rips_complex rips_complex_from_points(distances, threshold); + + Simplex_tree simplex; + if (rips_complex_from_points.create_complex(simplex, 1)) { + // ---------------------------------------------------------------------------- + // Display information about the one skeleton rips complex + // ---------------------------------------------------------------------------- + std::cout << "Rips complex is of dimension " << simplex.dimension() << + " - " << simplex.num_simplices() << " simplices - " << + simplex.num_vertices() << " vertices." << std::endl; + + std::cout << "Iterator on rips 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; +} |