message: fixed Marc's comments
diff: @@ -1471,7 +1471,7 @@ class Simplex_tree {
  * @param[in] dgm Persistence diagram obtained after calling this->extend_filtration and this->get_persistence.
  * @return A vector of four persistence diagrams. The first one is Ordinary, the second one is Relative, the third one is Extended+ and the fourth one is Extended-.
  */
  - std::vector<std::vector<std::pair<int, std::pair<double, double>>>> convert(const std::vector<std::pair<int, std::pair<double, double>>>& dgm){
  + std::vector<std::vector<std::pair<int, std::pair<double, double>>>> compute_extended_persistence_subdiagrams(const std::vector<std::pair<int, std::pair<double, double>>>& dgm){
  std::vector<std::vector<std::pair<int, std::pair<double, double>>>> new_dgm(4); double x, y;
  for(unsigned int i = 0; i < dgm.size(); i++){ int h = dgm[i].first; double px = dgm[i].second.first; double py = dgm[i].second.second;
  if(std::isinf(py)) continue;
  @@ -1487,7 +1487,7 @@ class Simplex_tree {
  return new_dgm;
  }
  - /** \brief Extend filtration for computing extended persistence.
  + /** \brief Extend filtration for computing extended persistence. This function only uses the filtration values at the 0-dimensional simplices, and computes the extended persistence diagram induced by the lower-star filtration computed with these values. Note that after calling this function, the filtration values are actually modified. The function compute_extended_persistence_subdiagrams retrieves the original values and separates the extended persistence diagram points w.r.t. their types (Ord, Rel, Ext+, Ext-) and should always be called after computing the persistent homology of the extended simplicial complex.
  */
  void extend_filtration() {
  