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Diffstat (limited to 'src/Witness_complex/include/gudhi')
7 files changed, 773 insertions, 0 deletions
diff --git a/src/Witness_complex/include/gudhi/Active_witness/Active_witness.h b/src/Witness_complex/include/gudhi/Active_witness/Active_witness.h new file mode 100644 index 00000000..2ae1d6e0 --- /dev/null +++ b/src/Witness_complex/include/gudhi/Active_witness/Active_witness.h @@ -0,0 +1,55 @@ +/* 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): Siargey Kachanovich + * + * Copyright (C) 2016 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#ifndef ACTIVE_WITNESS_ACTIVE_WITNESS_H_ +#define ACTIVE_WITNESS_ACTIVE_WITNESS_H_ + +#include <gudhi/Active_witness/Active_witness_iterator.h> +#include <list> + +namespace Gudhi { + +namespace witness_complex { + + /* \class Active_witness + * \brief Class representing a list of nearest neighbors to a given witness. + * \details Every element is a pair of a landmark identifier and the squared distance to it. + */ +template< typename Id_distance_pair, + typename INS_range > +class Active_witness { + public: + typedef Active_witness<Id_distance_pair, INS_range> ActiveWitness; + typedef typename INS_range::iterator INS_iterator; + typedef Active_witness_iterator< ActiveWitness, Id_distance_pair, INS_iterator > iterator; + typedef typename std::list<Id_distance_pair> Table; + + Table nearest_landmark_table_; + INS_range search_range_; + INS_iterator iterator_next_; + INS_iterator iterator_end_; + + Active_witness(const INS_range& search_range) + : search_range_(search_range), iterator_next_(search_range_.begin()), iterator_end_(search_range_.end()) { + } + + iterator begin() { + return iterator(this, nearest_landmark_table_.begin()); + } + + iterator end() { + return iterator(this); + } +}; + +} // namespace witness_complex +} // namespace Gudhi + +#endif // ACTIVE_WITNESS_ACTIVE_WITNESS_H_ diff --git a/src/Witness_complex/include/gudhi/Active_witness/Active_witness_iterator.h b/src/Witness_complex/include/gudhi/Active_witness/Active_witness_iterator.h new file mode 100644 index 00000000..4f8fddba --- /dev/null +++ b/src/Witness_complex/include/gudhi/Active_witness/Active_witness_iterator.h @@ -0,0 +1,96 @@ +/* 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): Siargey Kachanovich + * + * Copyright (C) 2016 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#ifndef ACTIVE_WITNESS_ACTIVE_WITNESS_ITERATOR_H_ +#define ACTIVE_WITNESS_ACTIVE_WITNESS_ITERATOR_H_ + +#include <boost/iterator/iterator_facade.hpp> +#include <list> + +namespace Gudhi { + +namespace witness_complex { + +/* \brief Iterator in the nearest landmark list. + * \details After the iterator reaches the end of the list, + * the list is augmented by a (nearest landmark, distance) pair if possible. + * If all the landmarks are present in the list, iterator returns the specific end value + * of the corresponding 'Active_witness' object. + */ +template< typename Active_witness, + typename Id_distance_pair, + typename INS_iterator > +class Active_witness_iterator + : public boost::iterator_facade< Active_witness_iterator <Active_witness, Id_distance_pair, INS_iterator>, + Id_distance_pair const, + boost::forward_traversal_tag, + Id_distance_pair const> { + friend class boost::iterator_core_access; + + typedef typename std::list<Id_distance_pair>::iterator Pair_iterator; + typedef typename Gudhi::witness_complex::Active_witness_iterator<Active_witness, + Id_distance_pair, + INS_iterator> Iterator; + + Active_witness *aw_; + Pair_iterator lh_; // landmark handle + bool is_end_; // true only if the pointer is end and there are no more neighbors to add + + public: + Active_witness_iterator(Active_witness* aw) + : aw_(aw), lh_(aw_->nearest_landmark_table_.end()), is_end_(true) { + } + + Active_witness_iterator(Active_witness* aw, const Pair_iterator& lh) + : aw_(aw), lh_(lh) { + is_end_ = false; + if (lh_ == aw_->nearest_landmark_table_.end()) { + if (aw_->iterator_next_ == aw_->iterator_end_) { + is_end_ = true; + } else { + aw_->nearest_landmark_table_.push_back(*aw_->iterator_next_); + lh_ = --aw_->nearest_landmark_table_.end(); + ++(aw_->iterator_next_); + } + } + } + + private : + Id_distance_pair& dereference() const { + return *lh_; + } + + bool equal(const Iterator& other) const { + return (is_end_ == other.is_end_) || (lh_ == other.lh_); + } + + void increment() { + // the neighbor search can't be at the end iterator of a list + GUDHI_CHECK(!is_end_ && lh_ != aw_->nearest_landmark_table_.end(), + std::logic_error("Wrong active witness increment.")); + // if the id of the current landmark is the same as the last one + + lh_++; + if (lh_ == aw_->nearest_landmark_table_.end()) { + if (aw_->iterator_next_ == aw_->iterator_end_) { + is_end_ = true; + } else { + aw_->nearest_landmark_table_.push_back(*aw_->iterator_next_); + lh_ = std::prev(aw_->nearest_landmark_table_.end()); + ++(aw_->iterator_next_); + } + } + } +}; + +} // namespace witness_complex +} // namespace Gudhi + +#endif // ACTIVE_WITNESS_ACTIVE_WITNESS_ITERATOR_H_ diff --git a/src/Witness_complex/include/gudhi/Euclidean_strong_witness_complex.h b/src/Witness_complex/include/gudhi/Euclidean_strong_witness_complex.h new file mode 100644 index 00000000..7d3c2d6d --- /dev/null +++ b/src/Witness_complex/include/gudhi/Euclidean_strong_witness_complex.h @@ -0,0 +1,106 @@ +/* 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): Siargey Kachanovich + * + * Copyright (C) 2015 Inria + * + * Modification(s): + * - 2019/08 Vincent Rouvreau: Fix issue #10 for CGAL and Eigen3 + * - YYYY/MM Author: Description of the modification + */ + +#ifndef EUCLIDEAN_STRONG_WITNESS_COMPLEX_H_ +#define EUCLIDEAN_STRONG_WITNESS_COMPLEX_H_ + +#include <gudhi/Strong_witness_complex.h> +#include <gudhi/Active_witness/Active_witness.h> +#include <gudhi/Kd_tree_search.h> + +#include <CGAL/version.h> // for CGAL_VERSION_NR + +#include <Eigen/src/Core/util/Macros.h> // for EIGEN_VERSION_AT_LEAST + +#include <utility> +#include <vector> + +// Make compilation fail - required for external projects - https://github.com/GUDHI/gudhi-devel/issues/10 +#if CGAL_VERSION_NR < 1041101000 +# error Alpha_complex_3d is only available for CGAL >= 4.11 +#endif + +#if !EIGEN_VERSION_AT_LEAST(3,1,0) +# error Alpha_complex_3d is only available for Eigen3 >= 3.1.0 installed with CGAL +#endif + +namespace Gudhi { + +namespace witness_complex { + +/** + * \private + * \class Euclidean_strong_witness_complex + * \brief Constructs strong witness complex for given sets of witnesses and landmarks in Euclidean space. + * \ingroup witness_complex + * + * \tparam Kernel_ requires a <a target="_blank" + * href="http://doc.cgal.org/latest/Kernel_d/classCGAL_1_1Epick__d.html">CGAL::Epick_d</a> class. + */ +template< class Kernel_ > +class Euclidean_strong_witness_complex + : public Strong_witness_complex<std::vector<typename Gudhi::spatial_searching::Kd_tree_search<Kernel_, + std::vector<typename Kernel_::Point_d>>::INS_range>> { + private: + typedef Kernel_ K; + typedef typename K::Point_d Point_d; + typedef std::vector<Point_d> Point_range; + typedef Gudhi::spatial_searching::Kd_tree_search<Kernel_, Point_range> Kd_tree; + typedef typename Kd_tree::INS_range Nearest_landmark_range; + typedef typename std::vector<Nearest_landmark_range> Nearest_landmark_table; + + typedef typename Nearest_landmark_range::Point_with_transformed_distance Id_distance_pair; + typedef typename Id_distance_pair::first_type Landmark_id; + typedef Landmark_id Vertex_handle; + + private: + Point_range landmarks_; + Kd_tree landmark_tree_; + using Strong_witness_complex<Nearest_landmark_table>::nearest_landmark_table_; + + public: + ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + /* @name Constructor + */ + + //@{ + + /** + * \brief Initializes member variables before constructing simplicial complex. + * \details Records landmarks from the range 'landmarks' into a + * table internally, as well as witnesses from the range 'witnesses'. + * Both ranges should have value_type Kernel_::Point_d. + */ + template< typename LandmarkRange, + typename WitnessRange > + Euclidean_strong_witness_complex(const LandmarkRange & landmarks, + const WitnessRange & witnesses) + : landmarks_(std::begin(landmarks), std::end(landmarks)), landmark_tree_(landmarks_) { + nearest_landmark_table_.reserve(boost::size(witnesses)); + for (auto w : witnesses) + nearest_landmark_table_.push_back(landmark_tree_.incremental_nearest_neighbors(w)); + } + + /** \brief Returns the point corresponding to the given vertex. + */ + template <typename Vertex_handle> + Point_d get_point(Vertex_handle vertex) const { + return landmarks_[vertex]; + } + + //@} +}; + +} // namespace witness_complex + +} // namespace Gudhi + +#endif // EUCLIDEAN_STRONG_WITNESS_COMPLEX_H_ diff --git a/src/Witness_complex/include/gudhi/Euclidean_witness_complex.h b/src/Witness_complex/include/gudhi/Euclidean_witness_complex.h new file mode 100644 index 00000000..21682ec4 --- /dev/null +++ b/src/Witness_complex/include/gudhi/Euclidean_witness_complex.h @@ -0,0 +1,108 @@ +/* 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): Siargey Kachanovich + * + * Copyright (C) 2015 Inria + * + * Modification(s): + * - 2019/08 Vincent Rouvreau: Fix issue #10 for CGAL and Eigen3 + * - YYYY/MM Author: Description of the modification + */ + +#ifndef EUCLIDEAN_WITNESS_COMPLEX_H_ +#define EUCLIDEAN_WITNESS_COMPLEX_H_ + +#include <gudhi/Witness_complex.h> +#include <gudhi/Active_witness/Active_witness.h> +#include <gudhi/Kd_tree_search.h> + +#include <CGAL/version.h> // for CGAL_VERSION_NR + +#include <Eigen/src/Core/util/Macros.h> // for EIGEN_VERSION_AT_LEAST + +#include <utility> +#include <vector> +#include <list> +#include <limits> + +// Make compilation fail - required for external projects - https://github.com/GUDHI/gudhi-devel/issues/10 +#if CGAL_VERSION_NR < 1041101000 +# error Alpha_complex_3d is only available for CGAL >= 4.11 +#endif + +#if !EIGEN_VERSION_AT_LEAST(3,1,0) +# error Alpha_complex_3d is only available for Eigen3 >= 3.1.0 installed with CGAL +#endif + +namespace Gudhi { + +namespace witness_complex { + +/** + * \private + * \class Euclidean_witness_complex + * \brief Constructs (weak) witness complex for given sets of witnesses and landmarks in Euclidean space. + * \ingroup witness_complex + * + * \tparam Kernel_ requires a <a target="_blank" + * href="http://doc.cgal.org/latest/Kernel_d/classCGAL_1_1Epick__d.html">CGAL::Epick_d</a> class. + */ +template< class Kernel_ > +class Euclidean_witness_complex + : public Witness_complex<std::vector<typename Gudhi::spatial_searching::Kd_tree_search<Kernel_, + std::vector<typename Kernel_::Point_d>>::INS_range>> { + private: + typedef Kernel_ K; + typedef typename K::Point_d Point_d; + typedef std::vector<Point_d> Point_range; + typedef Gudhi::spatial_searching::Kd_tree_search<Kernel_, Point_range> Kd_tree; + typedef typename Kd_tree::INS_range Nearest_landmark_range; + typedef typename std::vector<Nearest_landmark_range> Nearest_landmark_table; + + typedef typename Nearest_landmark_range::Point_with_transformed_distance Id_distance_pair; + typedef typename Id_distance_pair::first_type Landmark_id; + typedef Landmark_id Vertex_handle; + + private: + Point_range landmarks_; + Kd_tree landmark_tree_; + using Witness_complex<Nearest_landmark_table>::nearest_landmark_table_; + + public: + ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + /* @name Constructor + */ + + //@{ + + /** + * \brief Initializes member variables before constructing simplicial complex. + * \details Records landmarks from the range 'landmarks' into a + * table internally, as well as witnesses from the range 'witnesses'. + * Both ranges should have value_type Kernel_::Point_d. + */ + template< typename LandmarkRange, + typename WitnessRange > + Euclidean_witness_complex(const LandmarkRange & landmarks, + const WitnessRange & witnesses) + : landmarks_(std::begin(landmarks), std::end(landmarks)), landmark_tree_(landmarks) { + nearest_landmark_table_.reserve(boost::size(witnesses)); + for (auto w : witnesses) + nearest_landmark_table_.push_back(landmark_tree_.incremental_nearest_neighbors(w)); + } + + /** \brief Returns the point corresponding to the given vertex. + * @param[in] vertex Vertex handle of the point to retrieve. + */ + Point_d get_point(Vertex_handle vertex) const { + return landmarks_[vertex]; + } + + //@} +}; + +} // namespace witness_complex + +} // namespace Gudhi + +#endif // EUCLIDEAN_WITNESS_COMPLEX_H_ diff --git a/src/Witness_complex/include/gudhi/Strong_witness_complex.h b/src/Witness_complex/include/gudhi/Strong_witness_complex.h new file mode 100644 index 00000000..b3699f77 --- /dev/null +++ b/src/Witness_complex/include/gudhi/Strong_witness_complex.h @@ -0,0 +1,173 @@ +/* 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): Siargey Kachanovich + * + * Copyright (C) 2015 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#ifndef STRONG_WITNESS_COMPLEX_H_ +#define STRONG_WITNESS_COMPLEX_H_ + +#include <gudhi/Active_witness/Active_witness.h> + +#include <utility> +#include <vector> +#include <list> +#include <limits> + +namespace Gudhi { + +namespace witness_complex { + + /** + * \private + * \class Strong_witness_complex + * \brief Constructs strong 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 (one entry per witness) + * of sorted ranges 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>' + * where the first element is the index of the landmark, and the second its + * (squared) distance to the witness. + */ +template< class Nearest_landmark_table_ > +class Strong_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 + */ + + //@{ + + Strong_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>'. + */ + Strong_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 strong 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, 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, + Landmark_id limit_dimension = std::numeric_limits<Landmark_id>::max()) const { + Landmark_id complex_dim = 0; + if (complex.num_vertices() > 0) { + std::cerr << "Strong witness complex cannot create complex - complex is not empty.\n"; + return false; + } + if (max_alpha_square < 0) { + std::cerr << "Strong witness complex cannot create complex - squared relaxation parameter must be " + << "non-negative.\n"; + return false; + } + for (auto w : nearest_landmark_table_) { + ActiveWitness aw(w); + typeVectorVertex simplex; + typename ActiveWitness::iterator aw_it = aw.begin(); + float lim_dist2 = aw.begin()->second + max_alpha_square; + while ((Landmark_id)simplex.size() <= limit_dimension && aw_it != aw.end() && aw_it->second < lim_dist2) { + simplex.push_back(aw_it->first); + complex.insert_simplex_and_subfaces(simplex, aw_it->second - aw.begin()->second); + aw_it++; + } + // continue inserting limD-faces of the following simplices + typeVectorVertex& vertices = simplex; // 'simplex' now will be called vertices + while (aw_it != aw.end() && aw_it->second < lim_dist2) { + typeVectorVertex facet = {}; + add_all_faces_of_dimension(limit_dimension, vertices, vertices.begin(), aw_it, + aw_it->second - aw.begin()->second, facet, complex); + vertices.push_back(aw_it->first); + aw_it++; + } + if ((Landmark_id)simplex.size() - 1 > complex_dim) + complex_dim = simplex.size() - 1; + } + return true; + } + + //@} + + private: + /* \brief Adds recursively all the faces of a certain dimension dim-1 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 landmark pointed by aw_it is added to all formed simplices. + */ + template < typename SimplicialComplexForWitness > + void add_all_faces_of_dimension(Landmark_id dim, + typeVectorVertex& vertices, + typename typeVectorVertex::iterator curr_it, + typename ActiveWitness::iterator aw_it, + double filtration_value, + typeVectorVertex& simplex, + SimplicialComplexForWitness& sc) const { + if (dim > 0) { + while (curr_it != vertices.end()) { + simplex.push_back(*curr_it); + ++curr_it; + add_all_faces_of_dimension(dim-1, + vertices, + curr_it, + aw_it, + filtration_value, + simplex, + sc); + simplex.pop_back(); + add_all_faces_of_dimension(dim, + vertices, + curr_it, + aw_it, + filtration_value, + simplex, + sc); + } + } else if (dim == 0) { + simplex.push_back(aw_it->first); + sc.insert_simplex_and_subfaces(simplex, filtration_value); + simplex.pop_back(); + } + } +}; + +} // namespace witness_complex + +} // namespace Gudhi + +#endif // STRONG_WITNESS_COMPLEX_H_ diff --git a/src/Witness_complex/include/gudhi/Witness_complex.h b/src/Witness_complex/include/gudhi/Witness_complex.h new file mode 100644 index 00000000..d655c7f6 --- /dev/null +++ b/src/Witness_complex/include/gudhi/Witness_complex.h @@ -0,0 +1,192 @@ +/* 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): Siargey Kachanovich + * + * Copyright (C) 2015 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#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 (one entry per witness) + * of sorted ranges 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>' + * where the first element is the index of the landmark, and the second its + * (squared) distance to the witness. + */ + + 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.emplace_back(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_ diff --git a/src/Witness_complex/include/gudhi/Witness_complex/all_faces_in.h b/src/Witness_complex/include/gudhi/Witness_complex/all_faces_in.h new file mode 100644 index 00000000..5845728a --- /dev/null +++ b/src/Witness_complex/include/gudhi/Witness_complex/all_faces_in.h @@ -0,0 +1,43 @@ +/* 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): Siargey Kachanovich + * + * Copyright (C) 2015 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#ifndef WITNESS_COMPLEX_ALL_FACES_IN_H_ +#define WITNESS_COMPLEX_ALL_FACES_IN_H_ + +/* \brief Check if the facets of the k-dimensional simplex witnessed + * by witness witness_id are already in the complex. + * inserted_vertex is the handle of the (k+1)-th vertex witnessed by witness_id + */ +template < typename SimplicialComplexForWitness, + typename Simplex > + bool all_faces_in(Simplex& simplex, + double* filtration_value, + SimplicialComplexForWitness& sc) { + typedef typename SimplicialComplexForWitness::Simplex_handle Simplex_handle; + + if (simplex.size() == 1) + return true; /* Add vertices unconditionally */ + + Simplex facet; + for (typename Simplex::iterator not_it = simplex.begin(); not_it != simplex.end(); ++not_it) { + facet.clear(); + for (typename Simplex::iterator it = simplex.begin(); it != simplex.end(); ++it) + if (it != not_it) + facet.push_back(*it); + Simplex_handle facet_sh = sc.find(facet); + if (facet_sh == sc.null_simplex()) + return false; + else if (sc.filtration(facet_sh) > *filtration_value) + *filtration_value = sc.filtration(facet_sh); + } + return true; + } + +#endif // WITNESS_COMPLEX_ALL_FACES_IN_H_ |