Added example stuff

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/witness@968 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: a769b41f7d2d784a2740c149da08dac8124e3df9

1 files changed, 134 insertions, 0 deletions

diff --git a/src/Witness_complex/example/generators.h b/src/Witness_complex/example/generators.h
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+++ b/src/Witness_complex/example/generators.h
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+#ifndef GENERATORS_H
+#define GENERATORS_H
+
+#include <fstream>
+
+#include <CGAL/Epick_d.h>
+#include <CGAL/point_generators_d.h>
+
+typedef CGAL::Epick_d<CGAL::Dynamic_dimension_tag> K;
+typedef K::FT FT;
+typedef K::Point_d Point_d;
+typedef std::vector<Point_d> Point_Vector;
+typedef CGAL::Random_points_in_cube_d<Point_d> Random_cube_iterator;
+typedef CGAL::Random_points_in_ball_d<Point_d> Random_point_iterator;
+
+/**
+ * \brief Rock age method of reading off file
+ *
+ */
+inline void
+off_reader_cust ( std::string file_name , std::vector<Point_d> & 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;
+  // Line OFF. No need in it
+  if (!getline(in_file, line))
+    {
+      std::cerr << "No line OFF\n";
+      return;
+    }
+  // Line with 3 numbers. No need
+  if (!getline(in_file, line))
+    {
+      std::cerr << "No line with 3 numbers\n";
+      return;
+    }
+  // Reading points
+  while( getline ( in_file , line ) )
+    {
+      std::vector< double > point;
+      std::istringstream iss( line );
+      while(iss >> x) { point.push_back(x); }
+      points.push_back(Point_d(point));
+    }
+  in_file.close();
+}
+
+/**
+ * \brief Customized version of read_points
+ * which takes into account a possible nbP first line
+ *
+ */
+inline void
+read_points_cust ( std::string file_name , Point_Vector & 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); }
+      Point_d p(point.begin(), point.end());
+      if (point.size() != 1)
+        points.push_back(p);
+    }
+  in_file.close();
+}
+
+/** \brief Generate points on a grid in a cube of side 2
+ * having {+-1}^D as vertices and insert them in W.
+ * The grid has "width" points on each side. 
+ * If torus is true then it is supposed that the cube represents
+ * a flat torus, hence the opposite borders are associated.
+ * The points on border in this case are not placed twice.
+ */
+void generate_points_grid(Point_Vector& W, int width, int D, bool torus)
+{
+  int nb_points = 1;
+  for (int i = 0; i < D; ++i)
+    nb_points *= width;
+  for (int i = 0; i < nb_points; ++i)
+    {
+      std::vector<double> point;
+      int cell_i = i;
+      for (int l = 0; l < D; ++l)
+        {
+          if (torus)
+            point.push_back(-1+(2.0/(width-1))*(cell_i%width));
+          else
+            point.push_back(-1+(2.0/width)*(cell_i%width));
+          //attention: the bottom and the right are covered too!
+          cell_i /= width;
+        }
+      W.push_back(point);
+    }
+}
+
+/** \brief Generate nbP points uniformly in a cube of side 2
+ * having {+-1}^dim as its vertices and insert them in W.
+ */
+void generate_points_random_box(Point_Vector& W, int nbP, int dim)
+{
+  Random_cube_iterator rp(dim, 1.0);
+  for (int i = 0; i < nbP; i++)
+    {
+      W.push_back(*rp++);
+    }
+}
+
+/** \brief Generate nbP points uniformly on a (dim-1)-sphere
+ *  and insert them in W.
+ */
+void generate_points_sphere(Point_Vector& W, int nbP, int dim)
+{
+  CGAL::Random_points_on_sphere_d<Point_d> rp(dim,1);
+  for (int i = 0; i < nbP; i++)
+    W.push_back(*rp++);
+}
+
+
+#endif