From 85eec1ba750d56b66e3739dc486c6205f49fb31e Mon Sep 17 00:00:00 2001 From: ROUVREAU Vincent Date: Fri, 3 Jul 2020 16:04:45 +0200 Subject: A proposal for simplex_tree reset_filtration (python & C++) --- src/Simplex_tree/include/gudhi/Simplex_tree.h | 30 +++++++++++++++ src/Simplex_tree/test/simplex_tree_unit_test.cpp | 47 ++++++++++++++++++++++++ src/python/gudhi/simplex_tree.pxd | 1 + src/python/gudhi/simplex_tree.pyx | 10 +++++ src/python/test/test_simplex_tree.py | 22 +++++++++++ 5 files changed, 110 insertions(+) (limited to 'src') diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree.h b/src/Simplex_tree/include/gudhi/Simplex_tree.h index 889dbd00..adc8e801 100644 --- a/src/Simplex_tree/include/gudhi/Simplex_tree.h +++ b/src/Simplex_tree/include/gudhi/Simplex_tree.h @@ -1667,6 +1667,36 @@ class Simplex_tree { return sh; // None of its faces has the same filtration. } + public: + /** \brief This function resets filtration value until a given dimension. + * @param[in] filt_value The new filtration value. + * @param[in] max_dim The maximal dimension. + */ + void reset_filtration(Filtration_value filt_value, int max_dim) { + for (auto& simplex : root_.members()) { + simplex.second.assign_filtration(filt_value); + if (has_children(&simplex) && max_dim > 0) { + rec_reset_filtration(simplex.second.children(), filt_value, (max_dim - 1)); + } + } + clear_filtration(); // Drop the cache. + } + + private: + /** \brief Recursively resets filtration value until a given dimension. + * @param[in] sib Siblings to be parsed. + * @param[in] filt_value The new filtration value. + * @param[in] max_dim The maximal dimension. + */ + void rec_reset_filtration(Siblings * sib, Filtration_value filt_value, int max_dim) { + for (auto& simplex : sib->members()) { + simplex.second.assign_filtration(filt_value); + if (has_children(&simplex) && max_dim > 0) { + rec_reset_filtration(simplex.second.children(), filt_value, (max_dim - 1)); + } + } + } + private: Vertex_handle null_vertex_; /** \brief Total number of simplices in the complex, without the empty simplex.*/ diff --git a/src/Simplex_tree/test/simplex_tree_unit_test.cpp b/src/Simplex_tree/test/simplex_tree_unit_test.cpp index 9b5fa8fe..9780f5b0 100644 --- a/src/Simplex_tree/test/simplex_tree_unit_test.cpp +++ b/src/Simplex_tree/test/simplex_tree_unit_test.cpp @@ -940,3 +940,50 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(generators, typeST, list_of_tested_variants) { BOOST_CHECK(st.edge_with_same_filtration(st.find({1,5}))==st.find({1,5})); } } + +BOOST_AUTO_TEST_CASE_TEMPLATE(simplex_tree_reset_filtration, typeST, list_of_tested_variants) { + std::clog << "********************************************************************" << std::endl; + std::clog << "TEST RESET FILTRATION" << std::endl; + typeST st; + + st.insert_simplex_and_subfaces({2, 1, 0}, 3.); + st.insert_simplex_and_subfaces({3, 0}, 2.); + st.insert_simplex_and_subfaces({3, 4, 5}, 3.); + st.insert_simplex_and_subfaces({0, 1, 6, 7}, 4.); + + /* Inserted simplex: */ + /* 1 6 */ + /* o---o */ + /* /X\7/ */ + /* o---o---o---o */ + /* 2 0 3\X/4 */ + /* o */ + /* 5 */ + + for (auto f_simplex : st.skeleton_simplex_range(3)) { + std::clog << "vertex = ("; + for (auto vertex : st.simplex_vertex_range(f_simplex)) { + std::clog << vertex << ","; + } + std::clog << ") - filtration =" << st.filtration(f_simplex) << std::endl; + BOOST_CHECK(st.filtration(f_simplex) >= 2.); + } + + // dimension until 5 even if simplex tree is of dimension 3 to test the limits + for(int dimension = 0; dimension < 6; dimension ++) { + st.reset_filtration(0., dimension); + for (auto f_simplex : st.skeleton_simplex_range(3)) { + std::clog << "vertex = ("; + for (auto vertex : st.simplex_vertex_range(f_simplex)) { + std::clog << vertex << ","; + } + std::clog << ") - filtration =" << st.filtration(f_simplex) << std::endl; + if (st.dimension(f_simplex) > dimension) + BOOST_CHECK(st.filtration(f_simplex) >= 1.); + else + BOOST_CHECK(st.filtration(f_simplex) == 0.); + } + } + +} + diff --git a/src/python/gudhi/simplex_tree.pxd b/src/python/gudhi/simplex_tree.pxd index e748ac40..12c2065e 100644 --- a/src/python/gudhi/simplex_tree.pxd +++ b/src/python/gudhi/simplex_tree.pxd @@ -57,6 +57,7 @@ cdef extern from "Simplex_tree_interface.h" namespace "Gudhi": bool make_filtration_non_decreasing() nogil void compute_extended_filtration() nogil vector[vector[pair[int, pair[double, double]]]] compute_extended_persistence_subdiagrams(vector[pair[int, pair[double, double]]] dgm, double min_persistence) nogil + void reset_filtration(double filtration, int dimension) nogil # Iterators over Simplex tree pair[vector[int], double] get_simplex_and_filtration(Simplex_tree_simplex_handle f_simplex) nogil Simplex_tree_simplices_iterator get_simplices_iterator_begin() nogil diff --git a/src/python/gudhi/simplex_tree.pyx b/src/python/gudhi/simplex_tree.pyx index 20e66d9f..41b06116 100644 --- a/src/python/gudhi/simplex_tree.pyx +++ b/src/python/gudhi/simplex_tree.pyx @@ -358,6 +358,16 @@ cdef class SimplexTree: """ return self.get_ptr().make_filtration_non_decreasing() + def reset_filtration(self, filtration, max_dim): + """This function resets filtration value until a given dimension. + + :param filtration: New threshold value. + :type filtration: float. + :param max_dim: The maximal dimension. + :type max_dim: int. + """ + self.get_ptr().reset_filtration(filtration, max_dim) + 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 diff --git a/src/python/test/test_simplex_tree.py b/src/python/test/test_simplex_tree.py index 2137d822..1ca84c10 100755 --- a/src/python/test/test_simplex_tree.py +++ b/src/python/test/test_simplex_tree.py @@ -340,3 +340,25 @@ def test_simplices_iterator(): assert st.find(simplex[0]) == True print("filtration is: ", simplex[1]) assert st.filtration(simplex[0]) == simplex[1] + +def test_reset_filtration(): + st = SimplexTree() + + assert st.insert([0, 1, 2], 3.) == True + assert st.insert([0, 3], 2.) == True + assert st.insert([3, 4, 5], 3.) == True + assert st.insert([0, 1, 6, 7], 4.) == True + + for simplex in st.get_simplices(): + assert st.filtration(simplex[0]) >= 0. + + # dimension until 5 even if simplex tree is of dimension 3 to test the limits + for dimension in range(0, 6): + st.reset_filtration(0., dimension) + for simplex in st.get_skeleton(3): + print(simplex) + if len(simplex[0]) > (dimension + 1): + assert st.filtration(simplex[0]) >= 1. + else: + assert st.filtration(simplex[0]) == 0. + -- cgit v1.2.3