Alpha_kernel_d, its tests and Alpha complex to use it

1 files changed, 54 insertions, 0 deletions

diff --git a/src/Alpha_complex/example/Weighted_alpha_complex_from_points.cpp b/src/Alpha_complex/example/Weighted_alpha_complex_from_points.cpp
new file mode 100644
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+++ b/src/Alpha_complex/example/Weighted_alpha_complex_from_points.cpp
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+#include <gudhi/Alpha_complex.h>
+// to construct a simplex_tree from alpha complex
+#include <gudhi/Simplex_tree.h>
+
+#include <CGAL/Epeck_d.h>
+
+#include <iostream>
+#include <vector>
+
+// Explicit dimension 2 Epeck_d kernel
+using Kernel = CGAL::Epeck_d< CGAL::Dimension_tag<2> >;
+using Bare_point = Kernel::Point_d;
+using Weighted_point = Kernel::Weighted_point_d;
+using Vector_of_points = std::vector<Weighted_point>;
+
+int main() {
+  // ----------------------------------------------------------------------------
+  // Init of a list of points
+  // ----------------------------------------------------------------------------
+  Vector_of_points points;
+  points.push_back(Weighted_point(Bare_point(1.0, 1.0) , 1.));
+  points.push_back(Weighted_point(Bare_point(7.0, 0.0) , 1.));
+  points.push_back(Weighted_point(Bare_point(4.0, 6.0) , 1.));
+  points.push_back(Weighted_point(Bare_point(9.0, 6.0) , 1.));
+  points.push_back(Weighted_point(Bare_point(0.0, 14.0), 1.));
+  points.push_back(Weighted_point(Bare_point(2.0, 19.0), 1.));
+  points.push_back(Weighted_point(Bare_point(9.0, 17.0), 1.));
+
+  // ----------------------------------------------------------------------------
+  // Init of an alpha complex from the list of points
+  // ----------------------------------------------------------------------------
+  Gudhi::alpha_complex::Alpha_complex<Kernel, true> alpha_complex_from_weighted_points(points);
+
+  Gudhi::Simplex_tree<> simplex;
+  if (alpha_complex_from_weighted_points.create_complex(simplex)) {
+    // ----------------------------------------------------------------------------
+    // Display information about the alpha complex
+    // ----------------------------------------------------------------------------
+    std::clog << "Weighted alpha complex is of dimension " << simplex.dimension() <<
+        " - " << simplex.num_simplices() << " simplices - " <<
+        simplex.num_vertices() << " vertices." << std::endl;
+
+    std::clog << "Iterator on weighted alpha complex simplices in the filtration order, with [filtration value]:" << std::endl;
+    for (auto f_simplex : simplex.filtration_simplex_range()) {
+      std::clog << "   ( ";
+      for (auto vertex : simplex.simplex_vertex_range(f_simplex)) {
+        std::clog << vertex << " ";
+      }
+      std::clog << ") -> " << "[" << simplex.filtration(f_simplex) << "] ";
+      std::clog << std::endl;
+    }
+  }
+  return 0;
+}