1 files changed, 16 insertions, 8 deletions

diff --git a/src/cython/include/Subsampling_interface.h b/src/cython/include/Subsampling_interface.h
index fb047441..5fc16767 100644
--- a/src/cython/include/Subsampling_interface.h
+++ b/src/cython/include/Subsampling_interface.h
@@ -42,7 +42,8 @@ using Subsampling_point_d = Subsampling_dynamic_kernel::Point_d;
 using Subsampling_ft = Subsampling_dynamic_kernel::FT;
 
 // ------ choose_n_farthest_points ------
-std::vector<std::vector<double>> subsampling_n_farthest_points(std::vector<std::vector<double>>& points, unsigned nb_points) {
+std::vector<std::vector<double>> subsampling_n_farthest_points(const std::vector<std::vector<double>>& points,
+                                                               unsigned nb_points) {
   std::vector<std::vector<double>> landmarks;
   Subsampling_dynamic_kernel k;
   choose_n_farthest_points(k, points, nb_points, std::back_inserter(landmarks));
@@ -50,7 +51,8 @@ std::vector<std::vector<double>> subsampling_n_farthest_points(std::vector<std::
   return landmarks;
 }
 
-std::vector<std::vector<double>> subsampling_n_farthest_points(std::vector<std::vector<double>>& points, unsigned nb_points, unsigned starting_point) {
+std::vector<std::vector<double>> subsampling_n_farthest_points(const std::vector<std::vector<double>>& points,
+                                                               unsigned nb_points, unsigned starting_point) {
   std::vector<std::vector<double>> landmarks;
   Subsampling_dynamic_kernel k;
   choose_n_farthest_points(k, points, nb_points, starting_point, std::back_inserter(landmarks));
@@ -58,34 +60,39 @@ std::vector<std::vector<double>> subsampling_n_farthest_points(std::vector<std::
   return landmarks;
 }
 
-std::vector<std::vector<double>> subsampling_n_farthest_points_from_file(std::string& off_file, unsigned nb_points) {
+std::vector<std::vector<double>> subsampling_n_farthest_points_from_file(const std::string& off_file,
+                                                                         unsigned nb_points) {
   Gudhi::Points_off_reader<std::vector<double>> off_reader(off_file);
   std::vector<std::vector<double>> points = off_reader.get_point_cloud();
   return subsampling_n_farthest_points(points, nb_points);
 }
 
-std::vector<std::vector<double>> subsampling_n_farthest_points_from_file(std::string& off_file, unsigned nb_points, unsigned starting_point) {
+std::vector<std::vector<double>> subsampling_n_farthest_points_from_file(const std::string& off_file,
+                                                                         unsigned nb_points, unsigned starting_point) {
     Gudhi::Points_off_reader<std::vector<double>> off_reader(off_file);
     std::vector<std::vector<double>> points = off_reader.get_point_cloud();
     return subsampling_n_farthest_points(points, nb_points, starting_point);
 }
 
 // ------ pick_n_random_points ------
-std::vector<std::vector<double>> subsampling_n_random_points(std::vector<std::vector<double>>& points, unsigned nb_points) {
+std::vector<std::vector<double>> subsampling_n_random_points(const std::vector<std::vector<double>>& points,
+                                                             unsigned nb_points) {
   std::vector<std::vector<double>> landmarks;
   pick_n_random_points(points, nb_points, std::back_inserter(landmarks));
 
   return landmarks;
 }
 
-std::vector<std::vector<double>> subsampling_n_random_points_from_file(std::string& off_file, unsigned nb_points) {
+std::vector<std::vector<double>> subsampling_n_random_points_from_file(const std::string& off_file,
+                                                                       unsigned nb_points) {
   Gudhi::Points_off_reader<std::vector<double>> off_reader(off_file);
   std::vector<std::vector<double>> points = off_reader.get_point_cloud();
   return subsampling_n_random_points(points, nb_points);
 }
 
 // ------ sparsify_point_set ------
-std::vector<std::vector<double>> subsampling_sparsify_points(std::vector<std::vector<double>>& points, double min_squared_dist) {
+std::vector<std::vector<double>> subsampling_sparsify_points(const std::vector<std::vector<double>>& points,
+                                                             double min_squared_dist) {
   std::vector<Subsampling_point_d> input, output;
   for (auto point : points)
       input.push_back(Subsampling_point_d(point.size(), point.begin(), point.end()));
@@ -98,7 +105,8 @@ std::vector<std::vector<double>> subsampling_sparsify_points(std::vector<std::ve
   return landmarks;
 }
 
-std::vector<std::vector<double>> subsampling_sparsify_points_from_file(std::string& off_file, double min_squared_dist) {
+std::vector<std::vector<double>> subsampling_sparsify_points_from_file(const std::string& off_file,
+                                                                       double min_squared_dist) {
   Gudhi::Points_off_reader<std::vector<double>> off_reader(off_file);
   std::vector<std::vector<double>> points = off_reader.get_point_cloud();
   return subsampling_sparsify_points(points, min_squared_dist);