Add Cech complex. Do not compile yet.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/cechcomplex_vincent@3250 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: bef87ed8038444685b964175ea65860300917380

1 files changed, 85 insertions, 0 deletions

diff --git a/src/Cech_complex/include/gudhi/Cech_complex_blocker.h b/src/Cech_complex/include/gudhi/Cech_complex_blocker.h
new file mode 100644
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+++ b/src/Cech_complex/include/gudhi/Cech_complex_blocker.h
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+/*    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/>.
+ */
+
+#ifndef CECH_COMPLEX_BLOCKER_H_
+#define CECH_COMPLEX_BLOCKER_H_
+
+#include <gudhi/graph_simplicial_complex.h>
+#include <gudhi/Cech_complex.h>
+
+#include <Miniball/Miniball.hpp>
+
+#include <iostream>
+#include <vector>
+#include <cmath>  // for std::sqrt
+
+namespace Gudhi {
+
+namespace cech_complex {
+
+// Just declaring Cech_complex class because used and not yet defined.
+template<typename SimplicialComplexForCechComplex, typename ForwardPointRange>
+class Cech_complex;
+
+template <typename SimplicialComplexForCech, typename ForwardPointRange>
+class Cech_blocker {
+ private:
+  using Point = std::vector<double>;
+  using Point_cloud = std::vector<Point>;
+  using Point_iterator = Point_cloud::const_iterator;
+  using Coordinate_iterator = Point::const_iterator;
+  using Min_sphere = Miniball::Miniball<Miniball::CoordAccessor<Point_iterator, Coordinate_iterator>>;
+  using Simplex_handle = typename SimplicialComplexForCech::Simplex_handle;
+  using Filtration_value = typename SimplicialComplexForCech::Filtration_value;
+  using Cech_complex = Gudhi::cech_complex::Cech_complex<SimplicialComplexForCech, ForwardPointRange>;
+
+ public:
+  bool operator()(Simplex_handle sh) {
+    Point_cloud points;
+    for (auto vertex : simplicial_complex_.simplex_vertex_range(sh)) {
+      points.push_back(cc_ptr_->point(vertex));
+#ifdef DEBUG_TRACES
+      std::cout << "#(" << vertex << ")#";
+#endif  // DEBUG_TRACES
+    }
+    Min_sphere ms(cc_ptr_->dimension(), points.begin(),points.end());
+    Filtration_value radius = std::sqrt(ms.squared_radius());
+#ifdef DEBUG_TRACES
+    std::cout << "radius = " << radius << " - " << (radius > cc_ptr_->threshold()) << std::endl;
+#endif  // DEBUG_TRACES
+    simplicial_complex_.assign_filtration(sh, radius);
+    return (radius > cc_ptr_->threshold());
+  }
+  Cech_blocker(SimplicialComplexForCech& simplicial_complex, Cech_complex* cc_ptr)
+    : simplicial_complex_(simplicial_complex),
+      cc_ptr_(cc_ptr) {
+  }
+ private:
+  SimplicialComplexForCech simplicial_complex_;
+  Cech_complex* cc_ptr_;
+};
+
+}  // namespace cech_complex
+
+}  // namespace Gudhi
+
+#endif  // CECH_COMPLEX_BLOCKER_H_