diff options
author | Marc Glisse <marc.glisse@inria.fr> | 2020-03-07 14:05:05 +0100 |
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committer | Marc Glisse <marc.glisse@inria.fr> | 2020-03-07 14:05:05 +0100 |
commit | 35e08b30836fb0c419c0377eaf51d2a3b16e7670 (patch) | |
tree | f6e659e8d0b0b37c8ee4576a075fd727bcddd313 /src | |
parent | 64199fd8037556f135f90102ba8270cccf9d3e60 (diff) |
min_persistence for generators
Diffstat (limited to 'src')
-rw-r--r-- | src/python/gudhi/simplex_tree.pxd | 4 | ||||
-rw-r--r-- | src/python/gudhi/simplex_tree.pyx | 36 | ||||
-rw-r--r-- | src/python/include/Persistent_cohomology_interface.h | 10 |
3 files changed, 30 insertions, 20 deletions
diff --git a/src/python/gudhi/simplex_tree.pxd b/src/python/gudhi/simplex_tree.pxd index 4e435c67..53e2bbc9 100644 --- a/src/python/gudhi/simplex_tree.pxd +++ b/src/python/gudhi/simplex_tree.pxd @@ -53,5 +53,5 @@ cdef extern from "Persistent_cohomology_interface.h" namespace "Gudhi": vector[pair[double,double]] intervals_in_dimension(int dimension) void write_output_diagram(string diagram_file_name) vector[pair[vector[int], vector[int]]] persistence_pairs() - pair[vector[vector[int]], vector[vector[int]]] lower_star_generators() - pair[vector[vector[int]], vector[vector[int]]] flag_generators() + pair[vector[vector[int]], vector[vector[int]]] lower_star_generators(double) + pair[vector[vector[int]], vector[vector[int]]] flag_generators(double) diff --git a/src/python/gudhi/simplex_tree.pyx b/src/python/gudhi/simplex_tree.pyx index 1c9b9cf1..3f582ac9 100644 --- a/src/python/gudhi/simplex_tree.pyx +++ b/src/python/gudhi/simplex_tree.pyx @@ -395,7 +395,7 @@ 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 @@ -515,42 +515,48 @@ cdef class SimplexTree: print("intervals_in_dim function requires persistence function" " to be launched first.") - def lower_star_persistence_generators(self): + def lower_star_persistence_generators(self, min_persistence=0.): """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, + :param min_persistence: The minimum persistence value to take into + account (strictly greater than min_persistence). Default value is + 0.0. + Set min_persistence to -1.0 to see all values. + :type min_persistence: float. + :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: intervals_in_dim function requires - :func:`persistence()<gudhi.SimplexTree.persistence>` - function to be launched first. + :note: lower_star_persistence_generators requires that `persistence()` be called first. """ if self.pcohptr != NULL: - gen = self.pcohptr.lower_star_generators() + gen = self.pcohptr.lower_star_generators(min_persistence) normal = [np_array(d).reshape(-1,2) for d in gen.first] infinite = [np_array(d) for d in gen.second] return (normal, infinite) else: print("lower_star_persistence_generators() requires that persistence() be called first.") - def flag_persistence_generators(self): + def flag_persistence_generators(self, min_persistence=0.): """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; + :param min_persistence: The minimum persistence value to take into + account (strictly greater than min_persistence). Default value is + 0.0. + Set min_persistence to -1.0 to see all values. + :type min_persistence: float. + :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[List[numpy.array[int] of shape (n,3)], List[numpy.array[int] of shape (m,4)], List[numpy.array[int] of shape (l,)], List[numpy.array[int] of shape (k,2)]] + :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: intervals_in_dim function requires - :func:`persistence()<gudhi.SimplexTree.persistence>` - function to be launched first. + :note: flag_persistence_generators requires that `persistence()` be called first. """ if self.pcohptr != NULL: - gen = self.pcohptr.flag_generators() + gen = self.pcohptr.flag_generators(min_persistence) if len(gen.first) == 0: normal0 = np_array([]) normals = np_array([]) @@ -568,4 +574,4 @@ cdef class SimplexTree: return (normal0, normals, infinite0, infinites) else: - print("lower_star_persistence_generators() requires that persistence() be called first.") + print("flag_persistence_generators() requires that persistence() be called first.") diff --git a/src/python/include/Persistent_cohomology_interface.h b/src/python/include/Persistent_cohomology_interface.h index 6e9aac52..8e721fc0 100644 --- a/src/python/include/Persistent_cohomology_interface.h +++ b/src/python/include/Persistent_cohomology_interface.h @@ -95,11 +95,10 @@ persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomol } // TODO: (possibly at the python level) - // - an option to ignore intervals of length 0? // - an option to return only some of those vectors? typedef std::pair<std::vector<std::vector<int>>, std::vector<std::vector<int>>> Generators; - Generators lower_star_generators() { + Generators lower_star_generators(double min_persistence) { Generators out; // diags[i] should be interpreted as vector<array<int,2>> auto& diags = out.first; @@ -108,6 +107,8 @@ persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomol for (auto pair : Base::get_persistent_pairs()) { auto s = std::get<0>(pair); auto t = std::get<1>(pair); + if(stptr_->filtration(t) - stptr_->filtration(s) <= min_persistence) + continue; int dim = stptr_->dimension(s); auto v = stptr_->vertex_with_same_filtration(s); if(t == stptr_->null_simplex()) { @@ -123,7 +124,8 @@ persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomol return out; } - Generators flag_generators() { + // An alternative, to avoid those different sizes, would be to "pad" vertex generator v as (v, v) or (v, -1). When using it as index, this corresponds to adding the vertex filtration values either on the diagonal of the distance matrix, or as an extra row or column. + Generators flag_generators(double min_persistence) { Generators out; // diags[0] should be interpreted as vector<array<int,3>> and other diags[i] as vector<array<int,4>> auto& diags = out.first; @@ -132,6 +134,8 @@ persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomol for (auto pair : Base::get_persistent_pairs()) { auto s = std::get<0>(pair); auto t = std::get<1>(pair); + if(stptr_->filtration(t) - stptr_->filtration(s) <= min_persistence) + continue; int dim = stptr_->dimension(s); bool infinite = t == stptr_->null_simplex(); if(infinite) { |