From 55c7181126aa7defce38c9b82872d14223d4c1dd Mon Sep 17 00:00:00 2001
From: Gard Spreemann <gspreemann@gmail.com>
Date: Tue, 7 Feb 2017 17:33:01 +0100
Subject: Initial import of upstream's 1.3.1.

---
 .../Witness_complex/witness_complex_from_file.cpp  | 100 +++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 example/Witness_complex/witness_complex_from_file.cpp

(limited to 'example/Witness_complex/witness_complex_from_file.cpp')

diff --git a/example/Witness_complex/witness_complex_from_file.cpp b/example/Witness_complex/witness_complex_from_file.cpp
new file mode 100644
index 00000000..53207ad2
--- /dev/null
+++ b/example/Witness_complex/witness_complex_from_file.cpp
@@ -0,0 +1,100 @@
+/*    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";
+}
-- 
cgit v1.2.3