Add doc, example renamed

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/cechcomplex_vincent@3254 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: 666bacd07c711b89167c87155c21fe88688e2e68

1 files changed, 75 insertions, 0 deletions

diff --git a/src/Cech_complex/example/cech_complex_example_from_points.cpp b/src/Cech_complex/example/cech_complex_example_from_points.cpp
new file mode 100644
index 00000000..882849c3
--- /dev/null
+++ b/src/Cech_complex/example/cech_complex_example_from_points.cpp
@@ -0,0 +1,75 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       Vincent Rouvreau
+ *
+ *    Copyright (C) 2018 Inria
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <gudhi/Cech_complex.h>
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/distance_functions.h>
+
+#include <iostream>
+#include <string>
+#include <vector>
+#include <array>
+
+int main() {
+  // Type definitions
+  using Point_cloud = std::vector<std::array<double, 2>>;
+  using Simplex_tree = Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_fast_persistence>;
+  using Filtration_value = Simplex_tree::Filtration_value;
+  using Cech_complex = Gudhi::cech_complex::Cech_complex<Simplex_tree, Point_cloud>;
+
+  Point_cloud points;
+  points.push_back({1.0, 1.0});
+  points.push_back({7.0, 0.0});
+  points.push_back({4.0, 6.0});
+  points.push_back({9.0, 6.0});
+  points.push_back({0.0, 14.0});
+  points.push_back({2.0, 19.0});
+  points.push_back({9.0, 17.0});
+
+  // ----------------------------------------------------------------------------
+  // Init of a Cech complex from points
+  // ----------------------------------------------------------------------------
+  // 7.1 is a magic number to force one blocker, and one non-blocker
+  Filtration_value threshold = 7.1;
+  Cech_complex cech_complex_from_points(points, threshold, Gudhi::Euclidean_distance());
+
+  Simplex_tree stree;
+  cech_complex_from_points.create_complex(stree, 2);
+  // ----------------------------------------------------------------------------
+  // Display information about the one skeleton Cech complex
+  // ----------------------------------------------------------------------------
+  std::cout << "Cech complex is of dimension " << stree.dimension() <<
+               " - " << stree.num_simplices() << " simplices - " <<
+               stree.num_vertices() << " vertices." << std::endl;
+
+  std::cout << "Iterator on Cech complex simplices in the filtration order, with [filtration value]:" <<
+               std::endl;
+  for (auto f_simplex : stree.filtration_simplex_range()) {
+    std::cout << "   ( ";
+    for (auto vertex : stree.simplex_vertex_range(f_simplex)) {
+      std::cout << vertex << " ";
+    }
+    std::cout << ") -> " << "[" << stree.filtration(f_simplex) << "] ";
+    std::cout << std::endl;
+  }
+  return 0;
+}