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/* 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 Sophia Antipolis-Méditerranée (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/>.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <gudhi/Simplex_tree.h>
#include <gudhi/Witness_complex.h>
#include <gudhi/Landmark_choice_by_random_point.h>
#include <gudhi/reader_utils.h>
#include <iostream>
#include <fstream>
#include <ctime>
#include <string>
#include <vector>
typedef std::vector< Vertex_handle > typeVectorVertex;
typedef std::vector< std::vector <double> > Point_Vector;
/**
* \brief Customized version of read_points
* which takes into account a possible nbP first line
*
*/
inline void
read_points_cust(std::string file_name, std::vector< std::vector< double > > & points) {
std::ifstream in_file(file_name.c_str(), std::ios::in);
if (!in_file.is_open()) {
std::cerr << "Unable to open file " << file_name << std::endl;
return;
}
std::string line;
double x;
while (getline(in_file, line)) {
std::vector< double > point;
std::istringstream iss(line);
while (iss >> x) {
point.push_back(x);
}
if (point.size() != 1)
points.push_back(point);
}
in_file.close();
}
int main(int argc, char * const argv[]) {
if (argc != 3) {
std::cerr << "Usage: " << argv[0]
<< " path_to_point_file nbL \n";
return 0;
}
std::string file_name = argv[1];
int nbL = atoi(argv[2]);
clock_t start, end;
// Construct the Simplex Tree
Gudhi::Simplex_tree<> simplex_tree;
// Read the point file
Point_Vector point_vector;
read_points_cust(file_name, point_vector);
std::cout << "Successfully read " << point_vector.size() << " points.\n";
std::cout << "Ambient dimension is " << point_vector[0].size() << ".\n";
// Choose landmarks
start = clock();
std::vector<std::vector< int > > knn;
Gudhi::witness_complex::landmark_choice_by_random_point(point_vector, nbL, knn);
end = clock();
std::cout << "Landmark choice for " << nbL << " landmarks took "
<< static_cast<double>(end - start) / CLOCKS_PER_SEC << " s. \n";
// Compute witness complex
start = clock();
Gudhi::witness_complex::witness_complex(knn, nbL, point_vector[0].size(), simplex_tree);
end = clock();
std::cout << "Witness complex took "
<< static_cast<double>(end - start) / CLOCKS_PER_SEC << " s. \n";
}
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