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Diffstat (limited to 'src/python/include/Persistent_cohomology_interface.h')
-rw-r--r-- | src/python/include/Persistent_cohomology_interface.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/src/python/include/Persistent_cohomology_interface.h b/src/python/include/Persistent_cohomology_interface.h new file mode 100644 index 00000000..64e2ddc8 --- /dev/null +++ b/src/python/include/Persistent_cohomology_interface.h @@ -0,0 +1,111 @@ +/* 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): Vincent Rouvreau + * + * Copyright (C) 2016 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#ifndef INCLUDE_PERSISTENT_COHOMOLOGY_INTERFACE_H_ +#define INCLUDE_PERSISTENT_COHOMOLOGY_INTERFACE_H_ + +#include <gudhi/Persistent_cohomology.h> + +#include <vector> +#include <utility> // for std::pair +#include <algorithm> // for sort + +namespace Gudhi { + +template<class FilteredComplex> +class Persistent_cohomology_interface : public +persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomology::Field_Zp> { + private: + /* + * Compare two intervals by dimension, then by length. + */ + struct cmp_intervals_by_dim_then_length { + explicit cmp_intervals_by_dim_then_length(FilteredComplex * sc) + : sc_(sc) { } + + template<typename Persistent_interval> + bool operator()(const Persistent_interval & p1, const Persistent_interval & p2) { + if (sc_->dimension(get < 0 > (p1)) == sc_->dimension(get < 0 > (p2))) + return (sc_->filtration(get < 1 > (p1)) - sc_->filtration(get < 0 > (p1)) + > sc_->filtration(get < 1 > (p2)) - sc_->filtration(get < 0 > (p2))); + else + return (sc_->dimension(get < 0 > (p1)) > sc_->dimension(get < 0 > (p2))); + } + FilteredComplex* sc_; + }; + + public: + Persistent_cohomology_interface(FilteredComplex* stptr) + : persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomology::Field_Zp>(*stptr), + stptr_(stptr) { } + + Persistent_cohomology_interface(FilteredComplex* stptr, bool persistence_dim_max) + : persistent_cohomology::Persistent_cohomology<FilteredComplex, + persistent_cohomology::Field_Zp>(*stptr, persistence_dim_max), + stptr_(stptr) { } + + std::vector<std::pair<int, std::pair<double, double>>> get_persistence(int homology_coeff_field, + double min_persistence) { + persistent_cohomology::Persistent_cohomology<FilteredComplex, + persistent_cohomology::Field_Zp>::init_coefficients(homology_coeff_field); + persistent_cohomology::Persistent_cohomology<FilteredComplex, + persistent_cohomology::Field_Zp>::compute_persistent_cohomology(min_persistence); + + // Custom sort and output persistence + cmp_intervals_by_dim_then_length cmp(stptr_); + auto persistent_pairs = persistent_cohomology::Persistent_cohomology<FilteredComplex, + persistent_cohomology::Field_Zp>::get_persistent_pairs(); + std::sort(std::begin(persistent_pairs), std::end(persistent_pairs), cmp); + + std::vector<std::pair<int, std::pair<double, double>>> persistence; + for (auto pair : persistent_pairs) { + persistence.push_back(std::make_pair(stptr_->dimension(get<0>(pair)), + std::make_pair(stptr_->filtration(get<0>(pair)), + stptr_->filtration(get<1>(pair))))); + } + return persistence; + } + + std::vector<std::pair<std::vector<int>, std::vector<int>>> persistence_pairs() { + auto pairs = persistent_cohomology::Persistent_cohomology<FilteredComplex, + persistent_cohomology::Field_Zp>::get_persistent_pairs(); + + std::vector<std::pair<std::vector<int>, std::vector<int>>> persistence_pairs; + persistence_pairs.reserve(pairs.size()); + for (auto pair : pairs) { + std::vector<int> birth; + if (get<0>(pair) != stptr_->null_simplex()) { + for (auto vertex : stptr_->simplex_vertex_range(get<0>(pair))) { + birth.push_back(vertex); + } + } + + std::vector<int> death; + if (get<1>(pair) != stptr_->null_simplex()) { + for (auto vertex : stptr_->simplex_vertex_range(get<1>(pair))) { + death.push_back(vertex); + } + } + + persistence_pairs.push_back(std::make_pair(birth, death)); + } + return persistence_pairs; + } + + private: + // A copy + FilteredComplex* stptr_; +}; + +} // namespace Gudhi + +#endif // INCLUDE_PERSISTENT_COHOMOLOGY_INTERFACE_H_ |