Loading...
Searching...
No Matches
Persistence_graph.h
/* This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
* See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
* Author: Francois Godi
*
* Copyright (C) 2015 Inria
*
* Modification(s):
* - YYYY/MM Author: Description of the modification
*/
#ifndef PERSISTENCE_GRAPH_H_
#define PERSISTENCE_GRAPH_H_
#include <gudhi/Internal_point.h>
#ifdef GUDHI_USE_TBB
#include <tbb/parallel_sort.h>
#endif
#include <vector>
#include <algorithm>
#include <limits> // for numeric_limits
#include <cmath>
namespace Gudhi {
namespace persistence_diagram {
class Persistence_graph {
public:
template<typename Persistence_diagram1, typename Persistence_diagram2>
Persistence_graph(const Persistence_diagram1& diag1, const Persistence_diagram2& diag2, double e);
bool on_the_u_diagonal(int u_point_index) const;
bool on_the_v_diagonal(int v_point_index) const;
int corresponding_point_in_u(int v_point_index) const;
int corresponding_point_in_v(int u_point_index) const;
double distance(int u_point_index, int v_point_index) const;
int size() const;
double bottleneck_alive() const;
std::vector<double> sorted_distances() const;
double max_dist_to_diagonal() const;
Internal_point get_u_point(int u_point_index) const;
Internal_point get_v_point(int v_point_index) const;
private:
std::vector<Internal_point> u;
std::vector<Internal_point> v;
double b_alive;
};
template<typename Persistence_diagram1, typename Persistence_diagram2>
Persistence_graph::Persistence_graph(const Persistence_diagram1 &diag1,
const Persistence_diagram2 &diag2, double e)
: u(), v(), b_alive(0.) {
std::vector<double> u_alive;
std::vector<double> v_alive;
std::vector<double> u_nalive;
std::vector<double> v_nalive;
int u_inf = 0;
int v_inf = 0;
double inf = std::numeric_limits<double>::infinity();
double neginf = -inf;
for (auto it = std::begin(diag1); it != std::end(diag1); ++it) {
if (std::get<0>(*it) != inf && std::get<1>(*it) != neginf){
if (std::get<0>(*it) == neginf && std::get<1>(*it) == inf)
u_inf++;
else if (std::get<0>(*it) == neginf)
u_nalive.push_back(std::get<1>(*it));
else if (std::get<1>(*it) == inf)
u_alive.push_back(std::get<0>(*it));
else if (std::get<1>(*it) - std::get<0>(*it) > e)
u.push_back(Internal_point(std::get<0>(*it), std::get<1>(*it), u.size()));
}
}
for (auto it = std::begin(diag2); it != std::end(diag2); ++it) {
if (std::get<0>(*it) != inf && std::get<1>(*it) != neginf){
if (std::get<0>(*it) == neginf && std::get<1>(*it) == inf)
v_inf++;
else if (std::get<0>(*it) == neginf)
v_nalive.push_back(std::get<1>(*it));
else if (std::get<1>(*it) == inf)
v_alive.push_back(std::get<0>(*it));
else if (std::get<1>(*it) - std::get<0>(*it) > e)
v.push_back(Internal_point(std::get<0>(*it), std::get<1>(*it), v.size()));
}
}
if (u.size() < v.size())
swap(u, v);
if (u_alive.size() != v_alive.size() || u_nalive.size() != v_nalive.size() || u_inf != v_inf) {
b_alive = std::numeric_limits<double>::infinity();
} else {
std::sort(u_alive.begin(), u_alive.end());
std::sort(v_alive.begin(), v_alive.end());
std::sort(u_nalive.begin(), u_nalive.end());
std::sort(v_nalive.begin(), v_nalive.end());
for (auto it_u = u_alive.cbegin(), it_v = v_alive.cbegin(); it_u != u_alive.cend(); ++it_u, ++it_v)
b_alive = (std::max)(b_alive, std::fabs(*it_u - *it_v));
for (auto it_u = u_nalive.cbegin(), it_v = v_nalive.cbegin(); it_u != u_nalive.cend(); ++it_u, ++it_v)
b_alive = (std::max)(b_alive, std::fabs(*it_u - *it_v));
}
}
inline bool Persistence_graph::on_the_u_diagonal(int u_point_index) const {
return u_point_index >= static_cast<int> (u.size());
}
inline bool Persistence_graph::on_the_v_diagonal(int v_point_index) const {
return v_point_index >= static_cast<int> (v.size());
}
inline int Persistence_graph::corresponding_point_in_u(int v_point_index) const {
return on_the_v_diagonal(v_point_index) ?
v_point_index - static_cast<int> (v.size()) : v_point_index + static_cast<int> (u.size());
}
inline int Persistence_graph::corresponding_point_in_v(int u_point_index) const {
return on_the_u_diagonal(u_point_index) ?
u_point_index - static_cast<int> (u.size()) : u_point_index + static_cast<int> (v.size());
}
inline double Persistence_graph::distance(int u_point_index, int v_point_index) const {
if (on_the_u_diagonal(u_point_index) && on_the_v_diagonal(v_point_index))
return 0.;
Internal_point p_u = get_u_point(u_point_index);
Internal_point p_v = get_v_point(v_point_index);
return (std::max)(std::fabs(p_u.x() - p_v.x()), std::fabs(p_u.y() - p_v.y()));
}
inline int Persistence_graph::size() const {
return static_cast<int> (u.size() + v.size());
}
inline double Persistence_graph::bottleneck_alive() const {
return b_alive;
}
inline std::vector<double> Persistence_graph::sorted_distances() const {
std::vector<double> distances;
distances.push_back(0.); // for empty diagrams
for (int u_point_index = 0; u_point_index < size(); ++u_point_index) {
distances.push_back(distance(u_point_index, corresponding_point_in_v(u_point_index)));
for (int v_point_index = 0; v_point_index < size(); ++v_point_index)
distances.push_back(distance(u_point_index, v_point_index));
}
#ifdef GUDHI_USE_TBB
tbb::parallel_sort(distances.begin(), distances.end());
#else
std::sort(distances.begin(), distances.end());
#endif
return distances;
}
inline Internal_point Persistence_graph::get_u_point(int u_point_index) const {
if (!on_the_u_diagonal(u_point_index))
return u.at(u_point_index);
Internal_point projector = v.at(corresponding_point_in_v(u_point_index));
double m = (projector.x() + projector.y()) / 2.;
return Internal_point(m, m, u_point_index);
}
inline Internal_point Persistence_graph::get_v_point(int v_point_index) const {
if (!on_the_v_diagonal(v_point_index))
return v.at(v_point_index);
Internal_point projector = u.at(corresponding_point_in_u(v_point_index));
double m = (projector.x() + projector.y()) / 2.;
return Internal_point(m, m, v_point_index);
}
inline double Persistence_graph::max_dist_to_diagonal() const {
double max = 0.;
for (auto& p : u)
max = (std::max)(max, p.y() - p.x());
for (auto& p : v)
max = (std::max)(max, p.y() - p.x());
return max / 2;
}
} // namespace persistence_diagram
} // namespace Gudhi
#endif // PERSISTENCE_GRAPH_H_
std::get
constexpr auto & get(Gudhi::persistence_matrix::Persistence_interval< Dimension, Event_value > &i) noexcept
Partial specialization of get for Gudhi::persistence_matrix::Persistence_interval.
Definition persistence_interval.h:199
Gudhi
Gudhi namespace.
Definition SimplicialComplexForAlpha.h:14