Merge pull request #215 from MathieuCarriere/extended_persistence

Extended persistence

1 files changed, 40 insertions, 0 deletions

diff --git a/src/python/include/Simplex_tree_interface.h b/src/python/include/Simplex_tree_interface.h
index 4a7062d6..1a18aed6 100644
--- a/src/python/include/Simplex_tree_interface.h
+++ b/src/python/include/Simplex_tree_interface.h
@@ -37,8 +37,12 @@ class Simplex_tree_interface : public Simplex_tree<SimplexTreeOptions> {
   using Filtered_simplices = std::vector<Simplex_and_filtration>;
   using Skeleton_simplex_iterator = typename Base::Skeleton_simplex_iterator;
   using Complex_simplex_iterator = typename Base::Complex_simplex_iterator;
+  using Extended_filtration_data = typename Base::Extended_filtration_data;
 
  public:
+
+  Extended_filtration_data efd;
+  
   bool find_simplex(const Simplex& vh) {
     return (Base::find(vh) != Base::null_simplex());
   }
@@ -117,6 +121,42 @@ class Simplex_tree_interface : public Simplex_tree<SimplexTreeOptions> {
     return cofaces;
   }
 
+  void compute_extended_filtration() {
+    this->efd = this->extend_filtration();
+    this->initialize_filtration();
+    return;
+  }
+
+  std::vector<std::vector<std::pair<int, std::pair<Filtration_value, Filtration_value>>>> compute_extended_persistence_subdiagrams(const std::vector<std::pair<int, std::pair<Filtration_value, Filtration_value>>>& dgm, Filtration_value min_persistence){
+    std::vector<std::vector<std::pair<int, std::pair<Filtration_value, Filtration_value>>>> new_dgm(4);
+    for (unsigned int i = 0; i < dgm.size(); i++){
+      std::pair<Filtration_value, Extended_simplex_type> px = this->decode_extended_filtration(dgm[i].second.first, this->efd);
+      std::pair<Filtration_value, Extended_simplex_type> py = this->decode_extended_filtration(dgm[i].second.second, this->efd);
+      std::pair<int, std::pair<Filtration_value, Filtration_value>> pd_point = std::make_pair(dgm[i].first, std::make_pair(px.first, py.first));
+      if(std::abs(px.first - py.first) > min_persistence){
+        //Ordinary
+        if (px.second == Extended_simplex_type::UP && py.second == Extended_simplex_type::UP){
+          new_dgm[0].push_back(pd_point);
+        }
+        // Relative
+        else if (px.second == Extended_simplex_type::DOWN && py.second == Extended_simplex_type::DOWN){
+          new_dgm[1].push_back(pd_point);
+        }
+        else{
+          // Extended+
+          if (px.first < py.first){
+            new_dgm[2].push_back(pd_point);
+          }
+          //Extended-
+          else{
+            new_dgm[3].push_back(pd_point);
+          }
+        }
+      }
+    }
+    return new_dgm;
+  }
+
   void create_persistence(Gudhi::Persistent_cohomology_interface<Base>* pcoh) {
     Base::initialize_filtration();
     pcoh = new Gudhi::Persistent_cohomology_interface<Base>(*this);