diff options
Diffstat (limited to 'src/Bottleneck_distance/include/gudhi/Bottleneck.h')
| -rw-r--r-- | src/Bottleneck_distance/include/gudhi/Bottleneck.h | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/src/Bottleneck_distance/include/gudhi/Bottleneck.h b/src/Bottleneck_distance/include/gudhi/Bottleneck.h index 2b7e4767..b90a0ee0 100644 --- a/src/Bottleneck_distance/include/gudhi/Bottleneck.h +++ b/src/Bottleneck_distance/include/gudhi/Bottleneck.h @@ -24,6 +24,11 @@ #define BOTTLENECK_H_ #include <gudhi/Graph_matching.h> + +#include <vector> +#include <algorithm> // for max +#include <limits> // for numeric_limits + #include <cmath> namespace Gudhi { @@ -41,7 +46,7 @@ double bottleneck_distance_approx(Persistence_graph& g, double e) { if (step <= b_lower_bound || step >= b_upper_bound) // Avoid precision problem break; m.set_r(step); - while (m.multi_augment()); // compute a maximum matching (in the graph corresponding to the current r) + while (m.multi_augment()) {}; // compute a maximum matching (in the graph corresponding to the current r) if (m.perfect()) { m = biggest_unperfect; b_upper_bound = step; @@ -63,7 +68,7 @@ double bottleneck_distance_exact(Persistence_graph& g) { while (lower_bound_i != upper_bound_i) { long step = lower_bound_i + static_cast<long> ((upper_bound_i - lower_bound_i - 1) / alpha); m.set_r(sd.at(step)); - while (m.multi_augment()); // compute a maximum matching (in the graph corresponding to the current r) + while (m.multi_augment()) {}; // compute a maximum matching (in the graph corresponding to the current r) if (m.perfect()) { m = biggest_unperfect; upper_bound_i = step; @@ -75,11 +80,22 @@ double bottleneck_distance_exact(Persistence_graph& g) { return sd.at(lower_bound_i); } -/** \brief Function to use in order to compute the Bottleneck distance between two persistence diagrams (see concepts). - * If the last parameter e is not 0, you get an additive e-approximation, which is a lot faster to compute whatever is - * e. - * Thus, by default, e is a very small positive double, actually the smallest double possible such that the - * floating-point inaccuracies don't lead to a failure of the algorithm. +/** \brief Function to compute the Bottleneck distance between two persistence diagrams. + * + * \tparam Persistence_diagram1,Persistence_diagram2 + * models of the concept `PersistenceDiagram`. + * \param[in] e + * \parblock + * If `e` is 0, this uses an expensive algorithm to compute the exact distance. + * + * If `e` is not 0, it asks for an additive `e`-approximation, and currently + * also allows a small multiplicative error (the last 2 or 3 bits of the + * mantissa may be wrong). This version of the algorithm takes advantage of the + * limited precision of `double` and is usually a lot faster to compute, + * whatever the value of `e`. + * + * Thus, by default, `e` is the smallest positive double. + * \endparblock * * \ingroup bottleneck_distance */ |