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Diffstat (limited to 'src/GudhUI/utils/K_nearest_builder.h')
-rw-r--r-- | src/GudhUI/utils/K_nearest_builder.h | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/src/GudhUI/utils/K_nearest_builder.h b/src/GudhUI/utils/K_nearest_builder.h new file mode 100644 index 00000000..34483e58 --- /dev/null +++ b/src/GudhUI/utils/K_nearest_builder.h @@ -0,0 +1,77 @@ +/* This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. + * See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. + * Author(s): David Salinas + * + * Copyright (C) 2014 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#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_without_blockers(p, q); + } + } + } +}; + +#endif // UTILS_K_NEAREST_BUILDER_H_ |