diff options
Diffstat (limited to 'src/python/gudhi/simplex_tree.pyx')
| -rw-r--r-- | src/python/gudhi/simplex_tree.pyx | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/src/python/gudhi/simplex_tree.pyx b/src/python/gudhi/simplex_tree.pyx index 9479118a..b23885b4 100644 --- a/src/python/gudhi/simplex_tree.pyx +++ b/src/python/gudhi/simplex_tree.pyx @@ -9,6 +9,7 @@ from cython.operator import dereference, preincrement from libc.stdint cimport intptr_t +import numpy from numpy import array as np_array cimport simplex_tree @@ -100,6 +101,8 @@ cdef class SimplexTree: .. deprecated:: 3.2.0 """ + import warnings + warnings.warn("Since Gudhi 3.2, calling SimplexTree.initialize_filtration is unnecessary.", DeprecationWarning) self.get_ptr().initialize_filtration() def num_vertices(self): @@ -415,7 +418,7 @@ cdef class SimplexTree: :param min_persistence: The minimum persistence value to take into account (strictly greater than min_persistence). Default value is 0.0. - Sets min_persistence to -1.0 to see all values. + Set min_persistence to -1.0 to see all values. :type min_persistence: float. :param persistence_dim_max: If true, the persistent homology for the maximal dimension in the complex is computed. If false, it is @@ -527,3 +530,49 @@ cdef class SimplexTree: """ assert self.pcohptr != NULL, "compute_persistence() must be called before write_persistence_diagram()" self.pcohptr.write_output_diagram(persistence_file.encode('utf-8')) + + def lower_star_persistence_generators(self): + """Assuming this is a lower-star filtration, this function returns the persistence pairs, + where each simplex is replaced with the vertex that gave it its filtration value. + + :returns: First the regular persistence pairs, grouped by dimension, with one vertex per extremity, + and second the essential features, grouped by dimension, with one vertex each + :rtype: Tuple[List[numpy.array[int] of shape (n,2)], List[numpy.array[int] of shape (m,)]] + + :note: lower_star_persistence_generators requires that `persistence()` be called first. + """ + assert self.pcohptr != NULL, "lower_star_persistence_generators() requires that persistence() be called first." + gen = self.pcohptr.lower_star_generators() + normal = [np_array(d).reshape(-1,2) for d in gen.first] + infinite = [np_array(d) for d in gen.second] + return (normal, infinite) + + def flag_persistence_generators(self): + """Assuming this is a flag complex, this function returns the persistence pairs, + where each simplex is replaced with the vertices of the edges that gave it its filtration value. + + :returns: First the regular persistence pairs of dimension 0, with one vertex for birth and two for death; + then the other regular persistence pairs, grouped by dimension, with 2 vertices per extremity; + then the connected components, with one vertex each; + finally the other essential features, grouped by dimension, with 2 vertices for birth. + :rtype: Tuple[numpy.array[int] of shape (n,3), List[numpy.array[int] of shape (m,4)], numpy.array[int] of shape (l,), List[numpy.array[int] of shape (k,2)]] + + :note: flag_persistence_generators requires that `persistence()` be called first. + """ + assert self.pcohptr != NULL, "flag_persistence_generators() requires that persistence() be called first." + gen = self.pcohptr.flag_generators() + if len(gen.first) == 0: + normal0 = numpy.empty((0,3)) + normals = [] + else: + l = iter(gen.first) + normal0 = np_array(next(l)).reshape(-1,3) + normals = [np_array(d).reshape(-1,4) for d in l] + if len(gen.second) == 0: + infinite0 = numpy.empty(0) + infinites = [] + else: + l = iter(gen.second) + infinite0 = np_array(next(l)) + infinites = [np_array(d).reshape(-1,2) for d in l] + return (normal0, normals, infinite0, infinites) |