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Diffstat (limited to 'src/Persistence_representations/include/gudhi/Persistence_landscape_on_grid_exact.h')
-rw-r--r-- | src/Persistence_representations/include/gudhi/Persistence_landscape_on_grid_exact.h | 108 |
1 files changed, 0 insertions, 108 deletions
diff --git a/src/Persistence_representations/include/gudhi/Persistence_landscape_on_grid_exact.h b/src/Persistence_representations/include/gudhi/Persistence_landscape_on_grid_exact.h deleted file mode 100644 index 52f24195..00000000 --- a/src/Persistence_representations/include/gudhi/Persistence_landscape_on_grid_exact.h +++ /dev/null @@ -1,108 +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): Mathieu Carriere - * - * Copyright (C) 2018 INRIA (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 LANDSCAPE_H_ -#define LANDSCAPE_H_ - -// gudhi include -#include <gudhi/read_persistence_from_file.h> -#include <gudhi/common_persistence_representations.h> -#include <gudhi/Debug_utils.h> - -// standard include -#include <cmath> -#include <iostream> -#include <vector> -#include <limits> -#include <fstream> -#include <sstream> -#include <algorithm> -#include <string> -#include <utility> -#include <functional> - -namespace Gudhi { -namespace Persistence_representations { - -/** - * \class Persistence_landscape_on_grid_exact gudhi/Persistence_landscape_on_grid_exact.h - * \brief A class implementing exact persistence landscapes by approximating them on a collection of grid points - * - * \ingroup Persistence_representations - * - * \details - * In this class, we propose a way to approximate landscapes by sampling the x-axis of the persistence diagram and evaluating the (exact) landscape functions on the sample projections onto the diagonal. Note that this is a different approximation scheme - * from the one proposed in Persistence_landscape_on_grid, which puts a grid on the diagonal, maps the persistence intervals on this grid and computes the (approximate) landscape functions on the samples. - * Hence, the difference is that we do not modify the diagram in this implementation, but the code can be slower to run. -**/ - -class Persistence_landscape_on_grid_exact { - - protected: - Persistence_diagram diagram; - int res_x, nb_ls; - double min_x, max_x; - - public: - - /** \brief Persistence_landscape_on_grid_exact constructor. - * \ingroup Persistence_landscape_on_grid_exact - * - * @param[in] _diagram persistence diagram. - * @param[in] _nb_ls number of landscape functions. - * @param[in] _min_x minimum value of samples. - * @param[in] _max_x maximum value of samples. - * @param[in] _res_x number of samples. - * - */ - Persistence_landscape_on_grid_exact(const Persistence_diagram & _diagram, int _nb_ls = 5, double _min_x = 0.0, double _max_x = 1.0, int _res_x = 10){diagram = _diagram; nb_ls = _nb_ls; min_x = _min_x; max_x = _max_x; res_x = _res_x;} - - /** \brief Computes the landscape approximation of a diagram. - * \ingroup Persistence_landscape_on_grid_exact - * - */ - std::vector<std::vector<double> > vectorize() const { - std::vector<std::vector<double> > ls; for(int i = 0; i < nb_ls; i++) ls.emplace_back(); - int num_pts = diagram.size(); double step = (max_x - min_x)/(res_x - 1); - - std::vector<std::vector<double> > ls_t; for(int i = 0; i < res_x; i++) ls_t.emplace_back(); - for(int j = 0; j < num_pts; j++){ - double px = diagram[j].first; double py = diagram[j].second; double mid = (px+py)/2; - int first = std::ceil((px-min_x)/step); int middle = std::ceil((mid-min_x)/step); int last = std::ceil((py-min_x)/step); double x = min_x + first*step; - for(int i = first; i < middle; i++){ double value = std::sqrt(2)*(x-px); ls_t[i].push_back(value); x += step; } - for(int i = middle; i < last; i++){ double value = std::sqrt(2)*(py-x); ls_t[i].push_back(value); x += step; } - } - - for(int i = 0; i < res_x; i++){ - std::sort(ls_t[i].begin(), ls_t[i].end(), [](const double & a, const double & b){return a > b;}); - int nb_events_i = ls_t[i].size(); - for (int j = 0; j < nb_ls; j++){ if(j < nb_events_i) ls[j].push_back(ls_t[i][j]); else ls[j].push_back(0); } - } - - return ls; - } - -}; // class Persistence_landscape_on_grid_exact -} // namespace Persistence_representations -} // namespace Gudhi - -#endif // LANDSCAPE_H_ |