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Diffstat (limited to 'GudhUI/utils/K_nearest_builder.h')
-rw-r--r-- | GudhUI/utils/K_nearest_builder.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/GudhUI/utils/K_nearest_builder.h b/GudhUI/utils/K_nearest_builder.h new file mode 100644 index 00000000..7be0a4f4 --- /dev/null +++ b/GudhUI/utils/K_nearest_builder.h @@ -0,0 +1,90 @@ +/* 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): David Salinas + * + * Copyright (C) 2014 INRIA Sophia Antipolis-Mediterranee (France) + * + * 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 UTILS_K_NEAREST_BUILDER_H_ +#define UTILS_K_NEAREST_BUILDER_H_ + +#include <CGAL/Euclidean_distance.h> +#include <CGAL/Orthogonal_k_neighbor_search.h> +#include <CGAL/Search_traits_d.h> +#include <CGAL/Search_traits_adapter.h> +#include <CGAL/property_map.h> + +#include <unordered_map> +#include <list> +#include <utility> + +#include "utils/UI_utils.h" +#include "model/Complex_typedefs.h" + +template<typename SkBlComplex> class K_nearest_builder { + private: + typedef Geometry_trait Kernel; + typedef Point Point_d; + typedef std::pair<Point_d, unsigned> Point_d_with_id; + typedef CGAL::Search_traits_d<Kernel> Traits_base; + typedef CGAL::Search_traits_adapter<Point_d_with_id, CGAL::First_of_pair_property_map<Point_d_with_id>, + Traits_base> Traits; + typedef CGAL::Orthogonal_k_neighbor_search<Traits> Neighbor_search; + typedef Neighbor_search::Tree Tree; + typedef Neighbor_search::Distance Distance; + + SkBlComplex& complex_; + + public: + /** + * @brief Modify complex to be the expansion of the k-nearest neighbor + * symetric graph. + */ + K_nearest_builder(SkBlComplex& complex, unsigned k) : complex_(complex) { + complex.keep_only_vertices(); + compute_edges(k); + } + + private: + double squared_eucl_distance(const Point& p1, const Point& p2) const { + return Geometry_trait::Squared_distance_d()(p1, p2); + } + + void compute_edges(unsigned k) { + std::list<Point_d_with_id> points_with_id; + for (auto v : complex_.vertex_range()) { + Point_d_with_id point_v(complex_.point(v), v.vertex); + points_with_id.push_back(point_v); + } + + Tree tree(points_with_id.begin(), points_with_id.end()); + + typedef typename SkBlComplex::Vertex_handle Vertex_handle; + for (auto p : complex_.vertex_range()) { + Neighbor_search search(tree, complex_.point(p), k + 1); + for (auto it = ++search.begin(); it != search.end(); ++it) { + Vertex_handle q(std::get<1>(it->first)); + if (p != q && complex_.contains_vertex(p) && complex_.contains_vertex(q)) + complex_.add_edge(p, q); + } + } + } +}; + +#endif // UTILS_K_NEAREST_BUILDER_H_ |