diff options
Diffstat (limited to 'include/gudhi/Witness_complex.h')
| -rw-r--r-- | include/gudhi/Witness_complex.h | 201 |
1 files changed, 0 insertions, 201 deletions
diff --git a/include/gudhi/Witness_complex.h b/include/gudhi/Witness_complex.h deleted file mode 100644 index 67885258..00000000 --- a/include/gudhi/Witness_complex.h +++ /dev/null @@ -1,201 +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 - * - * 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 WITNESS_COMPLEX_H_ -#define WITNESS_COMPLEX_H_ - -#include <gudhi/Active_witness/Active_witness.h> -#include <gudhi/Witness_complex/all_faces_in.h> - -#include <utility> -#include <vector> -#include <list> -#include <limits> - -namespace Gudhi { - -namespace witness_complex { - -/** - * \private - * \class Witness_complex - * \brief Constructs (weak) witness complex for a given table of nearest landmarks with respect to witnesses. - * \ingroup witness_complex - * - * \tparam Nearest_landmark_table_ needs to be a range of a range of pairs of nearest landmarks and distances. - * The class Nearest_landmark_table_::value_type must be a copiable range. - * The range of pairs must admit a member type 'iterator'. The dereference type - * of the pair range iterator needs to be 'std::pair<std::size_t, double>'. -*/ -template< class Nearest_landmark_table_ > -class Witness_complex { - private: - typedef typename Nearest_landmark_table_::value_type Nearest_landmark_range; - typedef std::size_t Witness_id; - typedef std::size_t Landmark_id; - typedef std::pair<Landmark_id, double> Id_distance_pair; - typedef Active_witness<Id_distance_pair, Nearest_landmark_range> ActiveWitness; - typedef std::list< ActiveWitness > ActiveWitnessList; - typedef std::vector< Landmark_id > typeVectorVertex; - typedef std::vector<Nearest_landmark_range> Nearest_landmark_table_internal; - typedef Landmark_id Vertex_handle; - - protected: - Nearest_landmark_table_internal nearest_landmark_table_; - - public: - ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////// - /* @name Constructor - */ - - //@{ - - Witness_complex() { - } - - /** - * \brief Initializes member variables before constructing simplicial complex. - * \details Records nearest landmark table. - * @param[in] nearest_landmark_table needs to be a range of a range of pairs of nearest landmarks and distances. - * The class Nearest_landmark_table_::value_type must be a copiable range. - * The range of pairs must admit a member type 'iterator'. The dereference type - * of the pair range iterator needs to be 'std::pair<std::size_t, double>'. - */ - - Witness_complex(Nearest_landmark_table_ const & nearest_landmark_table) - : nearest_landmark_table_(std::begin(nearest_landmark_table), std::end(nearest_landmark_table)) { - } - - /** \brief Outputs the (weak) witness complex of relaxation 'max_alpha_square' - * in a simplicial complex data structure. - * \details The function returns true if the construction is successful and false otherwise. - * @param[out] complex Simplicial complex data structure compatible which is a model of - * SimplicialComplexForWitness concept. - * @param[in] max_alpha_square Maximal squared relaxation parameter. - * @param[in] limit_dimension Represents the maximal dimension of the simplicial complex - * (default value = no limit). - */ - template < typename SimplicialComplexForWitness > - bool create_complex(SimplicialComplexForWitness& complex, - double max_alpha_square, - std::size_t limit_dimension = std::numeric_limits<std::size_t>::max()) const { - if (complex.num_vertices() > 0) { - std::cerr << "Witness complex cannot create complex - complex is not empty.\n"; - return false; - } - if (max_alpha_square < 0) { - std::cerr << "Witness complex cannot create complex - squared relaxation parameter must be non-negative.\n"; - return false; - } - ActiveWitnessList active_witnesses; - Landmark_id k = 0; /* current dimension in iterative construction */ - for (auto w : nearest_landmark_table_) - active_witnesses.push_back(ActiveWitness(w)); - while (!active_witnesses.empty() && k <= limit_dimension) { - typename ActiveWitnessList::iterator aw_it = active_witnesses.begin(); - std::vector<Landmark_id> simplex; - simplex.reserve(k+1); - while (aw_it != active_witnesses.end()) { - bool ok = add_all_faces_of_dimension(k, - max_alpha_square, - std::numeric_limits<double>::infinity(), - aw_it->begin(), - simplex, - complex, - aw_it->end()); - assert(simplex.empty()); - if (!ok) - active_witnesses.erase(aw_it++); // First increase the iterator and then erase the previous element - else - aw_it++; - } - k++; - } - return true; - } - - //@} - - private: - /* \brief Adds recursively all the faces of a certain dimension dim witnessed by the same witness. - * Iterator is needed to know until how far we can take landmarks to form simplexes. - * simplex is the prefix of the simplexes to insert. - * The output value indicates if the witness rests active or not. - */ - template < typename SimplicialComplexForWitness > - bool add_all_faces_of_dimension(int dim, - double alpha2, - double norelax_dist2, - typename ActiveWitness::iterator curr_l, - std::vector<Landmark_id>& simplex, - SimplicialComplexForWitness& sc, - typename ActiveWitness::iterator end) const { - if (curr_l == end) - return false; - bool will_be_active = false; - typename ActiveWitness::iterator l_it = curr_l; - if (dim > 0) { - for (; l_it != end && l_it->second - alpha2 <= norelax_dist2; ++l_it) { - simplex.push_back(l_it->first); - if (sc.find(simplex) != sc.null_simplex()) { - typename ActiveWitness::iterator next_it = l_it; - will_be_active = add_all_faces_of_dimension(dim-1, - alpha2, - norelax_dist2, - ++next_it, - simplex, - sc, - end) || will_be_active; - } - assert(!simplex.empty()); - simplex.pop_back(); - // If norelax_dist is infinity, change to first omitted distance - if (l_it->second <= norelax_dist2) - norelax_dist2 = l_it->second; - } - } else if (dim == 0) { - for (; l_it != end && l_it->second - alpha2 <= norelax_dist2; ++l_it) { - simplex.push_back(l_it->first); - double filtration_value = 0; - // if norelax_dist is infinite, relaxation is 0. - if (l_it->second > norelax_dist2) - filtration_value = l_it->second - norelax_dist2; - if (all_faces_in(simplex, &filtration_value, sc)) { - will_be_active = true; - sc.insert_simplex(simplex, filtration_value); - } - assert(!simplex.empty()); - simplex.pop_back(); - // If norelax_dist is infinity, change to first omitted distance - if (l_it->second < norelax_dist2) - norelax_dist2 = l_it->second; - } - } - return will_be_active; - } -}; - -} // namespace witness_complex - -} // namespace Gudhi - -#endif // WITNESS_COMPLEX_H_ |