Remove traces from tangential

Tests the limits for choose_n_farthest_points and fix random


git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/trunk@1808 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: 53eec1efbc138080d1b202c2cdd4e7ff8cdde266

1 files changed, 15 insertions, 5 deletions

diff --git a/src/Subsampling/include/gudhi/choose_n_farthest_points.h b/src/Subsampling/include/gudhi/choose_n_farthest_points.h
index 40c7808d..9b45c640 100644
--- a/src/Subsampling/include/gudhi/choose_n_farthest_points.h
+++ b/src/Subsampling/include/gudhi/choose_n_farthest_points.h
@@ -60,10 +60,15 @@ void choose_n_farthest_points(Kernel const &k,
                               std::size_t final_size,
                               std::size_t starting_point,
                               OutputIterator output_it) {
-  typename Kernel::Squared_distance_d sqdist = k.squared_distance_d_object();
-
   std::size_t nb_points = boost::size(input_pts);
-  assert(nb_points >= final_size);
+  if (final_size > nb_points)
+    final_size = nb_points;
+
+  // Tests to the limit
+  if (final_size < 1)
+    return;
+
+  typename Kernel::Squared_distance_d sqdist = k.squared_distance_d_object();
 
   std::size_t current_number_of_landmarks = 0;  // counter for landmarks
   const double infty = std::numeric_limits<double>::infinity();  // infinity (see next entry)
@@ -107,11 +112,16 @@ void choose_n_farthest_points(Kernel const& k,
                               Point_container const &input_pts,
                               unsigned final_size,
                               OutputIterator output_it) {
+  // Tests to the limit
+  if ((final_size < 1) || (input_pts.size() == 0))
+    return;
+
   // Choose randomly the first landmark
   std::random_device rd;
   std::mt19937 gen(rd());
-  std::uniform_int_distribution<> dis(1, 6);
-  int starting_point = dis(gen);
+  std::uniform_int_distribution<> dis(0, (input_pts.size() - 1));
+  std::size_t starting_point = dis(gen);
+
   choose_n_farthest_points(k, input_pts, final_size, starting_point, output_it);
 }