diff options
Diffstat (limited to 'src/python')
| -rw-r--r-- | src/python/gudhi/simplex_tree.pxd | 2 | ||||
| -rw-r--r-- | src/python/gudhi/simplex_tree.pyx | 18 | ||||
| -rwxr-xr-x | src/python/test/test_simplex_tree.py | 82 |
3 files changed, 102 insertions, 0 deletions
diff --git a/src/python/gudhi/simplex_tree.pxd b/src/python/gudhi/simplex_tree.pxd index 82f155de..ae32eb82 100644 --- a/src/python/gudhi/simplex_tree.pxd +++ b/src/python/gudhi/simplex_tree.pxd @@ -57,6 +57,8 @@ 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]]]] compute_extended_persistence_subdiagrams(vector[pair[int, pair[double, double]]]) # Iterators over Simplex tree pair[vector[int], double] get_simplex_and_filtration(Simplex_tree_simplex_handle f_simplex) Simplex_tree_simplices_iterator get_simplices_iterator_begin() diff --git a/src/python/gudhi/simplex_tree.pyx b/src/python/gudhi/simplex_tree.pyx index c01cc905..733ecb97 100644 --- a/src/python/gudhi/simplex_tree.pyx +++ b/src/python/gudhi/simplex_tree.pyx @@ -396,6 +396,24 @@ cdef class SimplexTree: """ return self.get_ptr().make_filtration_non_decreasing() + def extend_filtration(self): + """ 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 :func:`compute_extended_persistence_subdiagrams()<gudhi.SimplexTree.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. + """ + return self.get_ptr().extend_filtration() + + def compute_extended_persistence_subdiagrams(self, dgm): + """This function retrieves good values for extended persistence, and separate the diagrams into the ordinary, relative, extended+ and extended- subdiagrams. + + :param dgm: Persistence diagram obtained after calling :func:`extend_filtration()<gudhi.SimplexTree.extend_filtration>` and :func:`persistence()<gudhi.SimplexTree.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-. + + .. note:: + + This function should be called only after calling :func:`extend_filtration()<gudhi.SimplexTree.extend_filtration>` and :func:`persistence()<gudhi.SimplexTree.persistence>`. + """ + return self.get_ptr().compute_extended_persistence_subdiagrams(dgm) + + def persistence(self, homology_coeff_field=11, min_persistence=0, persistence_dim_max = False): """This function returns the persistence of the simplicial complex. diff --git a/src/python/test/test_simplex_tree.py b/src/python/test/test_simplex_tree.py index f7848379..caefeb9c 100755 --- a/src/python/test/test_simplex_tree.py +++ b/src/python/test/test_simplex_tree.py @@ -245,6 +245,88 @@ def test_make_filtration_non_decreasing(): assert st.filtration([0, 1, 6]) == 1.0 assert st.filtration([0, 1]) == 1.0 assert st.filtration([0]) == 1.0 + +def test_extend_filtration(): + + # Inserted simplex: + # 5 4 + # o o + # / \ / + # o o + # /2\ /3 + # o o + # 1 0 + + st = SimplexTree() + st.insert([0,2]) + st.insert([1,2]) + st.insert([0,3]) + st.insert([2,5]) + st.insert([3,4]) + st.insert([3,5]) + st.assign_filtration([0], 1.) + st.assign_filtration([1], 2.) + st.assign_filtration([2], 3.) + st.assign_filtration([3], 4.) + st.assign_filtration([4], 5.) + st.assign_filtration([5], 6.) + + assert st.get_filtration() == [ + ([0, 2], 0.0), + ([1, 2], 0.0), + ([0, 3], 0.0), + ([3, 4], 0.0), + ([2, 5], 0.0), + ([3, 5], 0.0), + ([0], 1.0), + ([1], 2.0), + ([2], 3.0), + ([3], 4.0), + ([4], 5.0), + ([5], 6.0) + ] + + + st.extend_filtration() + + assert st.get_filtration() == [ + ([6], -3.0), + ([0], -2.0), + ([1], -1.8), + ([2], -1.6), + ([0, 2], -1.6), + ([1, 2], -1.6), + ([3], -1.4), + ([0, 3], -1.4), + ([4], -1.2), + ([3, 4], -1.2), + ([5], -1.0), + ([2, 5], -1.0), + ([3, 5], -1.0), + ([5, 6], 1.0), + ([4, 6], 1.2), + ([3, 6], 1.4), + ([3, 4, 6], 1.4), + ([3, 5, 6], 1.4), + ([2, 6], 1.6), + ([2, 5, 6], 1.6), + ([1, 6], 1.8), + ([1, 2, 6], 1.8), + ([0, 6], 2.0), + ([0, 2, 6], 2.0), + ([0, 3, 6], 2.0) + ] + + + dgm = st.persistence() + L = st.compute_extended_persistence_subdiagrams(dgm) + assert L == [ + [(0, (1.9999999999999998, 2.9999999999999996))], + [(1, (5.0, 4.0))], + [(0, (1.0, 6.0))], + [(1, (6.0, 1.0))] + ] + assert st.filtration([1]) == 1.0 assert st.filtration([3, 4, 5]) == 2.0 assert st.filtration([3, 4]) == 2.0 |