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Diffstat (limited to 'include/gudhi/Landmark_choice_by_random_point.h')
| -rw-r--r-- | include/gudhi/Landmark_choice_by_random_point.h | 96 |
1 files changed, 0 insertions, 96 deletions
diff --git a/include/gudhi/Landmark_choice_by_random_point.h b/include/gudhi/Landmark_choice_by_random_point.h deleted file mode 100644 index ebf6aad1..00000000 --- a/include/gudhi/Landmark_choice_by_random_point.h +++ /dev/null @@ -1,96 +0,0 @@ -/* 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): Siargey Kachanovich - * - * Copyright (C) 2015 INRIA Sophia Antipolis-Méditerranée (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 LANDMARK_CHOICE_BY_RANDOM_POINT_H_ -#define LANDMARK_CHOICE_BY_RANDOM_POINT_H_ - -#include <boost/range/size.hpp> - -#include <queue> // for priority_queue<> -#include <utility> // for pair<> -#include <iterator> -#include <vector> -#include <set> - -namespace Gudhi { - -namespace witness_complex { - - /** - * \ingroup witness_complex - * \brief Landmark choice strategy by taking random vertices for landmarks. - * \details It chooses nbL distinct landmarks from a random access range `points` - * and outputs a matrix {witness}*{closest landmarks} in knn. - * - * The type KNearestNeighbors can be seen as - * Witness_range<Closest_landmark_range<Vertex_handle>>, where - * Witness_range and Closest_landmark_range are random access ranges and - * Vertex_handle is the label type of a vertex in a simplicial complex. - * Closest_landmark_range needs to have push_back operation. - */ - - template <typename KNearestNeighbours, - typename Point_random_access_range> - void landmark_choice_by_random_point(Point_random_access_range const &points, - int nbL, - KNearestNeighbours &knn) { - int nbP = boost::size(points); - assert(nbP >= nbL); - std::set<int> landmarks; - int current_number_of_landmarks = 0; // counter for landmarks - - // TODO(SK) Consider using rand_r(...) instead of rand(...) for improved thread safety - int chosen_landmark = rand() % nbP; - for (current_number_of_landmarks = 0; current_number_of_landmarks != nbL; current_number_of_landmarks++) { - while (landmarks.find(chosen_landmark) != landmarks.end()) - chosen_landmark = rand() % nbP; - landmarks.insert(chosen_landmark); - } - - int dim = boost::size(*std::begin(points)); - typedef std::pair<double, int> dist_i; - typedef bool (*comp)(dist_i, dist_i); - knn = KNearestNeighbours(nbP); - for (int points_i = 0; points_i < nbP; points_i++) { - std::priority_queue<dist_i, std::vector<dist_i>, comp> l_heap([](dist_i j1, dist_i j2) { - return j1.first > j2.first; - }); - std::set<int>::iterator landmarks_it; - int landmarks_i = 0; - for (landmarks_it = landmarks.begin(), landmarks_i = 0; landmarks_it != landmarks.end(); - ++landmarks_it, landmarks_i++) { - dist_i dist = std::make_pair(euclidean_distance(points[points_i], points[*landmarks_it]), landmarks_i); - l_heap.push(dist); - } - for (int i = 0; i < dim + 1; i++) { - dist_i dist = l_heap.top(); - knn[points_i].push_back(dist.second); - l_heap.pop(); - } - } - } - -} // namespace witness_complex - -} // namespace Gudhi - -#endif // LANDMARK_CHOICE_BY_RANDOM_POINT_H_ |