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Diffstat (limited to 'include/gudhi/writing_persistence_to_file.h')
-rw-r--r-- | include/gudhi/writing_persistence_to_file.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/include/gudhi/writing_persistence_to_file.h b/include/gudhi/writing_persistence_to_file.h new file mode 100644 index 00000000..34448576 --- /dev/null +++ b/include/gudhi/writing_persistence_to_file.h @@ -0,0 +1,117 @@ +/* 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): Pawel Dlotko + * + * Copyright (C) 2017 Swansea University, UK + * + * 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 WRITING_PERSISTENCE_TO_FILE_H_ +#define WRITING_PERSISTENCE_TO_FILE_H_ + +#include <iostream> +#include <string> +#include <limits> + +namespace Gudhi { + +/** +* This is a class to store persistence intervals. Its main purpose is to +* exchange data in between different packages and provide unified way +* of writing a collection of persistence intervals to file. +**/ +template <typename Filtration_type, typename Coefficient_field> +class Persistence_interval_common { + public: + /** + * Constructor taking as an input birth and death of the pair. + **/ + Persistence_interval_common(Filtration_type birth, Filtration_type death) + : birth_(birth), + death_(death), + dimension_(std::numeric_limits<unsigned>::max()), + arith_element_(std::numeric_limits<Coefficient_field>::max()) {} + + /** + * Constructor taking as an input birth, death and dimension of the pair. + **/ + Persistence_interval_common(Filtration_type birth, Filtration_type death, unsigned dim) + : birth_(birth), death_(death), dimension_(dim), arith_element_(std::numeric_limits<Coefficient_field>::max()) {} + + /** +* Constructor taking as an input birth, death, dimension of the pair as well +* as the number p such that this interval is present over Z_p field. +**/ + Persistence_interval_common(Filtration_type birth, Filtration_type death, unsigned dim, Coefficient_field field) + : birth_(birth), death_(death), dimension_(dim), arith_element_(field) {} + + /** + * Operator to compare two persistence pairs. During the comparision all the + * fields: birth, death, dimensiona and arith_element_ are taken into account + * and they all have to be equal for two pairs to be equal. + **/ + bool operator==(const Persistence_interval_common& i2) const { + return ((this->birth_ == i2.birth_) && (this->death_ == i2.death_) && (this->dimension_ == i2.dimension_) && + (this->arith_element_ == i2.arith_element_)); + } + + /** + * Check if two persistence paris are not equal. + **/ + bool operator!=(const Persistence_interval_common& i2) const { return (!((*this) == i2)); } + + /** + * Operator to compare objects of a type Persistence_interval_common. + * One intervals is smaller than the other if it has lower persistence. + * Note that this operator do not take Arith_element into account when doing comparisions. + **/ + bool operator<(const Persistence_interval_common& i2) const { + return fabs(this->death_ - this->birth_) < fabs(i2.death_ - i2.birth_); + } + + friend std::ostream& operator<<(std::ostream& out, const Persistence_interval_common& it) { + if (it.arith_element_ != std::numeric_limits<Coefficient_field>::max()) { + out << it.arith_element_ << " "; + } + if (it.dimension_ != std::numeric_limits<unsigned>::max()) { + out << it.dimension_ << " "; + } + out << it.birth_ << " " << it.death_ << " "; + return out; + } + + private: + Filtration_type birth_; + Filtration_type death_; + unsigned dimension_; + Coefficient_field arith_element_; +}; + +/** + * This function write a vector<Persistence_interval_common> to a stream +**/ +template <typename Persistence_interval_range> +void write_persistence_intervals_to_stream(const Persistence_interval_range& intervals, + std::ostream& out = std::cout) { + for (auto interval : intervals) { + out << interval << "\n"; + } +} + +} // namespace Gudhi + +#endif // WRITING_PERSISTENCE_TO_FILE_H_ |