1 files changed, 56 insertions, 0 deletions
diff --git a/src/Alpha_complex/example/Alpha_complex_3d_from_points.cpp b/src/Alpha_complex/example/Alpha_complex_3d_from_points.cpp
new file mode 100644
index 00000000..0e359a27
--- /dev/null
+++ b/src/Alpha_complex/example/Alpha_complex_3d_from_points.cpp
@@ -0,0 +1,56 @@
+#include <gudhi/Alpha_complex_3d.h>
+// to construct a simplex_tree from alpha complex
+#include <gudhi/Simplex_tree.h>
+
+#include <iostream>
+#include <string>
+#include <vector>
+#include <limits>  // for numeric limits
+
+using Alpha_complex_3d = Gudhi::alpha_complex::Alpha_complex_3d<Gudhi::alpha_complex::complexity::SAFE, false, false>;
+using Point = Alpha_complex_3d::Point_3;
+using Vector_of_points = std::vector<Point>;
+
+int main(int argc, char **argv) {
+  if (argc != 1) {
+    std::cerr << "Error: Number of arguments (" << argc << ") is not correct\n";
+    std::cerr << "Usage: " << (argv[0] - 1) << " \n";
+    exit(-1);  // ----- >>
+  }
+
+  // ----------------------------------------------------------------------------
+  // Init of a list of points from a small molecule
+  // ----------------------------------------------------------------------------
+  Vector_of_points points;
+  points.push_back(Point(1, -1, -1));
+  points.push_back(Point(-1, 1, -1));
+  points.push_back(Point(-1, -1, 1));
+  points.push_back(Point(1, 1, 1));
+  points.push_back(Point(2, 2, 2));
+
+  // ----------------------------------------------------------------------------
+  // Init of an alpha complex from the list of points
+  // ----------------------------------------------------------------------------
+  Alpha_complex_3d alpha_complex_from_points(points);
+
+  Gudhi::Simplex_tree<> simplex;
+  if (alpha_complex_from_points.create_complex(simplex)) {
+    // ----------------------------------------------------------------------------
+    // 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;
+}