1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
/* 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
*
* 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/Points_off_io.h>
#include <gudhi/Simplex_tree.h>
#include <gudhi/Witness_complex.h>
#include <gudhi/Construct_closest_landmark_table.h>
#include <gudhi/pick_n_random_points.h>
#include <gudhi/reader_utils.h>
#include <iostream>
#include <fstream>
#include <ctime>
#include <string>
#include <vector>
typedef Gudhi::Simplex_tree<> Simplex_tree;
typedef std::vector< Simplex_tree::Vertex_handle > typeVectorVertex;
typedef std::vector< std::vector <double> > Point_Vector;
int main(int argc, char * const argv[]) {
if (argc != 3) {
std::cerr << "Usage: " << argv[0]
<< " path_to_point_file.off nbL \n";
return 0;
}
std::string off_file_name = argv[1];
int nbL = atoi(argv[2]);
clock_t start, end;
// Construct the Simplex Tree
Simplex_tree simplex_tree;
// Read the OFF file (input file name given as parameter) and triangulate points
Gudhi::Points_off_reader<std::vector <double>> off_reader(off_file_name);
// Check the read operation was correct
if (!off_reader.is_valid()) {
std::cerr << "Unable to read file " << off_file_name << std::endl;
}
// Read the point file
Point_Vector point_vector = off_reader.get_point_cloud();
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;
Point_Vector landmarks;
Gudhi::subsampling::pick_n_random_points(point_vector, 100, std::back_inserter(landmarks));
Gudhi::witness_complex::construct_closest_landmark_table<Simplex_tree::Filtration_value>(point_vector, landmarks, 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";
}
|
