added extended persistence function

2 files changed, 16 insertions, 0 deletions

diff --git a/src/python/gudhi/simplex_tree.pxd b/src/python/gudhi/simplex_tree.pxd
index 1066d44b..39f2a45f 100644
--- a/src/python/gudhi/simplex_tree.pxd
+++ b/src/python/gudhi/simplex_tree.pxd
@@ -43,6 +43,8 @@ cdef extern from "Simplex_tree_interface.h" namespace "Gudhi":
         void remove_maximal_simplex(vector[int] simplex)
         bool prune_above_filtration(double filtration)
         bool make_filtration_non_decreasing()
+        void extend_filtration()
+        vector[vector[pair[int, pair[double, double]]]] convert(vector[pair[int, pair[double, double]]])
 
 cdef extern from "Persistent_cohomology_interface.h" namespace "Gudhi":
     cdef cppclass Simplex_tree_persistence_interface "Gudhi::Persistent_cohomology_interface<Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_full_featured>>":
diff --git a/src/python/gudhi/simplex_tree.pyx b/src/python/gudhi/simplex_tree.pyx
index b18627c4..cfab14f4 100644
--- a/src/python/gudhi/simplex_tree.pyx
+++ b/src/python/gudhi/simplex_tree.pyx
@@ -386,6 +386,20 @@ cdef class SimplexTree:
         """
         return self.get_ptr().make_filtration_non_decreasing()
 
+    def extend_filtration(self):
+        """ This function extends filtration for computing extended persistence.
+        """
+        return self.get_ptr().extend_filtration()
+
+    def convert(self, dgm):
+        """This function retrieves good values for extended persistence, and separate the diagrams into the ordinary, relative, extended+ and extended- subdiagrams. Need extend_filtration to be called first!
+
+        :param dgm: Persistence diagram obtained after calling this->extend_filtration and this->get_persistence.
+        :returns: 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-.
+        """
+        return self.get_ptr().convert(dgm)
+
+
     def persistence(self, homology_coeff_field=11, min_persistence=0, persistence_dim_max = False):
         """This function returns the persistence of the simplicial complex.