1 files changed, 57 insertions, 0 deletions
diff --git a/src/Witness_complex/example/example_strong_witness_complex_off.cpp b/src/Witness_complex/example/example_strong_witness_complex_off.cpp
new file mode 100644
index 00000000..19f73836
--- /dev/null
+++ b/src/Witness_complex/example/example_strong_witness_complex_off.cpp
@@ -0,0 +1,57 @@
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Euclidean_strong_witness_complex.h>
+#include <gudhi/pick_n_random_points.h>
+#include <gudhi/choose_n_farthest_points.h>
+#include <gudhi/Points_off_io.h>
+
+#include <CGAL/Epick_d.h>
+
+#include <iostream>
+#include <fstream>
+#include <ctime>
+#include <string>
+#include <vector>
+
+using K = CGAL::Epick_d<CGAL::Dynamic_dimension_tag>;
+using Point_d = typename K::Point_d;
+using Witness_complex = Gudhi::witness_complex::Euclidean_strong_witness_complex<K>;
+using Point_vector = std::vector<Point_d>;
+
+int main(int argc, char* const argv[]) {
+  if (argc != 5) {
+    std::cerr << "Usage: " << argv[0] << " path_to_point_file number_of_landmarks max_squared_alpha limit_dimension\n";
+    return 0;
+  }
+
+  std::string file_name = argv[1];
+  int nbL = atoi(argv[2]), lim_dim = atoi(argv[4]);
+  double alpha2 = atof(argv[3]);
+  clock_t start, end;
+  Gudhi::Simplex_tree<> simplex_tree;
+
+  // Read the point file
+  Point_vector point_vector, landmarks;
+  Gudhi::Points_off_reader<Point_d> off_reader(file_name);
+  if (!off_reader.is_valid()) {
+    std::cerr << "Strong witness complex - Unable to read file " << file_name << "\n";
+    exit(-1);  // ----- >>
+  }
+  point_vector = Point_vector(off_reader.get_point_cloud());
+
+  std::cout << "Successfully read " << point_vector.size() << " points.\n";
+  std::cout << "Ambient dimension is " << point_vector[0].dimension() << ".\n";
+
+  // Choose landmarks (decomment one of the following two lines)
+  // Gudhi::subsampling::pick_n_random_points(point_vector, nbL, std::back_inserter(landmarks));
+  Gudhi::subsampling::choose_n_farthest_points(K(), point_vector, nbL, Gudhi::subsampling::random_starting_point,
+                                               std::back_inserter(landmarks));
+
+  // Compute witness complex
+  start = clock();
+  Witness_complex witness_complex(landmarks, point_vector);
+
+  witness_complex.create_complex(simplex_tree, alpha2, lim_dim);
+  end = clock();
+  std::cout << "Strong witness complex took " << static_cast<double>(end - start) / CLOCKS_PER_SEC << " s. \n";
+  std::cout << "Number of simplices is: " << simplex_tree.num_simplices() << "\n";
+}