diff options
| -rw-r--r-- | src/Simplex_tree/include/gudhi/Simplex_tree.h | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree.h b/src/Simplex_tree/include/gudhi/Simplex_tree.h index 6e51d107..4c6a95e8 100644 --- a/src/Simplex_tree/include/gudhi/Simplex_tree.h +++ b/src/Simplex_tree/include/gudhi/Simplex_tree.h @@ -771,12 +771,6 @@ class Simplex_tree { * assigned a Simplex_key corresponding to its order in the filtration (from 0 to m-1 for a * simplicial complex with m simplices). * - * The use of a depth-first traversal of the simplex tree, provided by - * complex_simplex_range(), combined with - * a stable sort is meant to optimize the order of simplices with same - * filtration value. The heuristic consists in inserting the cofaces of a - * simplex as soon as possible. - * * Will be automatically called when calling filtration_simplex_range() * if the filtration has never been initialized yet. */ void initialize_filtration() { @@ -785,7 +779,15 @@ class Simplex_tree { for (Simplex_handle sh : complex_simplex_range()) filtration_vect_.push_back(sh); - // the stable sort ensures the ordering heuristic + /* We use stable_sort here because with libstdc++ it is faster than sort. + * is_before_in_filtration is now a total order, but we used to call + * stable_sort for the following heuristic: + * The use of a depth-first traversal of the simplex tree, provided by + * complex_simplex_range(), combined with a stable sort is meant to + * optimize the order of simplices with same filtration value. The + * heuristic consists in inserting the cofaces of a simplex as soon as + * possible. + */ std::stable_sort(filtration_vect_.begin(), filtration_vect_.end(), is_before_in_filtration(this)); } |