diff options
Diffstat (limited to 'src/Persistent_cohomology/include/gudhi/Persistent_cohomology.h')
-rw-r--r-- | src/Persistent_cohomology/include/gudhi/Persistent_cohomology.h | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/src/Persistent_cohomology/include/gudhi/Persistent_cohomology.h b/src/Persistent_cohomology/include/gudhi/Persistent_cohomology.h index f6773bac..3e761473 100644 --- a/src/Persistent_cohomology/include/gudhi/Persistent_cohomology.h +++ b/src/Persistent_cohomology/include/gudhi/Persistent_cohomology.h @@ -431,9 +431,12 @@ class Persistent_cohomology { std::map<Simplex_key, Arith_element> & map_a_ds, Simplex_handle sigma, int dim_sigma) { // traverses the boundary of sigma, keeps track of the annotation vectors, - // with multiplicity, in a map. - std::map<Column *, int> annotations_in_boundary; - std::pair<typename std::map<Column *, int>::iterator, bool> result_insert_bound; + // with multiplicity. We used to sum the coefficients directly in + // annotations_in_boundary by using a map, we now do it later. + typedef std::pair<Column *, int> annotation_t; + // Danger: not thread-safe! + static std::vector<annotation_t> annotations_in_boundary; + annotations_in_boundary.clear(); int sign = 1 - 2 * (dim_sigma % 2); // \in {-1,1} provides the sign in the // alternate sum in the boundary. Simplex_key key; @@ -445,22 +448,29 @@ class Persistent_cohomology { // Find its annotation vector curr_col = ds_repr_[dsets_.find_set(key)]; if (curr_col != NULL) { // and insert it in annotations_in_boundary with multyiplicative factor "sign". - result_insert_bound = annotations_in_boundary.insert(std::pair<Column *, int>(curr_col, sign)); - if (!(result_insert_bound.second)) { - result_insert_bound.first->second += sign; - } + annotations_in_boundary.emplace_back(curr_col, sign); } } sign = -sign; } + // Place identical annotations consecutively so we can easily sum their multiplicities. + std::sort(annotations_in_boundary.begin(), annotations_in_boundary.end(), + [](annotation_t const& a, annotation_t const& b) { return a.first < b.first; }); + // Sum the annotations with multiplicity, using a map<key,coeff> // to represent a sparse vector. std::pair<typename std::map<Simplex_key, Arith_element>::iterator, bool> result_insert_a_ds; - for (auto ann_ref : annotations_in_boundary) { - if (ann_ref.second != coeff_field_.additive_identity()) { // For all columns in the boundary, - for (auto cell_ref : ann_ref.first->col_) { // insert every cell in map_a_ds with multiplicity - Arith_element w_y = coeff_field_.times(cell_ref.coefficient_, ann_ref.second); // coefficient * multiplicity + for (auto ann_it = annotations_in_boundary.begin(); ann_it != annotations_in_boundary.end(); /**/) { + Column* col = ann_it->first; + int mult = ann_it->second; + while (++ann_it != annotations_in_boundary.end() && ann_it->first == col) { + mult += ann_it->second; + } + // The following test is just a heuristic, it is not required, and it is fine that is misses p == 0. + if (mult != coeff_field_.additive_identity()) { // For all columns in the boundary, + for (auto cell_ref : col->col_) { // insert every cell in map_a_ds with multiplicity + Arith_element w_y = coeff_field_.times(cell_ref.coefficient_, mult); // coefficient * multiplicity if (w_y != coeff_field_.additive_identity()) { // if != 0 result_insert_a_ds = map_a_ds.insert(std::pair<Simplex_key, Arith_element>(cell_ref.key_, w_y)); |