1 files changed, 48 insertions, 0 deletions
diff --git a/src/Alpha_complex/example/Alpha_complex_from_off.cpp b/src/Alpha_complex/example/Alpha_complex_from_off.cpp
new file mode 100644
index 00000000..e140fe3d
--- /dev/null
+++ b/src/Alpha_complex/example/Alpha_complex_from_off.cpp
@@ -0,0 +1,48 @@
+#include <iostream>
+#include <string>
+
+// to construct a Delaunay_triangulation from a OFF file
+#include <gudhi/Delaunay_triangulation_off_io.h>
+#include <gudhi/Alpha_complex.h>
+
+void usage(char * const progName) {
+  std::cerr << "Usage: " << progName << " filename.off alpha_square_max_value" << std::endl;
+  std::cerr << "       i.e.: " << progName << " ../../data/points/alphacomplexdoc.off 60.0" << std::endl;
+  exit(-1); // ----- >>
+}
+
+int main(int argc, char **argv) {
+  if (argc != 3) {
+    std::cerr << "Error: Number of arguments (" << argc << ") is not correct" << std::endl;
+    usage(argv[0]);
+  }
+
+  std::string off_file_name(argv[1]);
+  double alpha_square_max_value = atof(argv[2]);
+
+  // ----------------------------------------------------------------------------
+  // Init of an alpha complex from an OFF file
+  // ----------------------------------------------------------------------------
+  typedef CGAL::Epick_d< CGAL::Dynamic_dimension_tag > Kernel;
+  Gudhi::alphacomplex::Alpha_complex<Kernel> alpha_complex_from_file(off_file_name, alpha_square_max_value);
+
+  // ----------------------------------------------------------------------------
+  // Display information about the alpha complex
+  // ----------------------------------------------------------------------------
+  std::cout << "Alpha complex is of dimension " << alpha_complex_from_file.dimension() <<
+      " - " << alpha_complex_from_file.num_simplices() << " simplices - " <<
+      alpha_complex_from_file.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 : alpha_complex_from_file.filtration_simplex_range()) {
+    if (alpha_complex_from_file.filtration(f_simplex) <= alpha_complex_from_file.filtration()) {
+      std::cout << "   ( ";
+      for (auto vertex : alpha_complex_from_file.simplex_vertex_range(f_simplex)) {
+        std::cout << vertex << " ";
+      }
+      std::cout << ") -> " << "[" << alpha_complex_from_file.filtration(f_simplex) << "] ";
+      std::cout << std::endl;
+    }
+  }
+  return 0;
+}