diff options
Diffstat (limited to 'src/Persistence_representations/include/gudhi/Persistence_image.h')
| -rw-r--r-- | src/Persistence_representations/include/gudhi/Persistence_image.h | 41 |
1 files changed, 25 insertions, 16 deletions
diff --git a/src/Persistence_representations/include/gudhi/Persistence_image.h b/src/Persistence_representations/include/gudhi/Persistence_image.h index 6c9f75b7..76b34d8d 100644 --- a/src/Persistence_representations/include/gudhi/Persistence_image.h +++ b/src/Persistence_representations/include/gudhi/Persistence_image.h @@ -26,8 +26,8 @@ // gudhi include #include <gudhi/read_persistence_from_file.h> #include <gudhi/common_persistence_representations.h> +#include <gudhi/Weight_functions.h> #include <gudhi/Debug_utils.h> -#include <gudhi/Persistence_weighted_gaussian.h> // standard include #include <cmath> @@ -41,39 +41,49 @@ #include <utility> #include <functional> -using PD = std::vector<std::pair<double,double> >; -using Weight = std::function<double (std::pair<double,double>) >; - namespace Gudhi { namespace Persistence_representations { /** * \class Persistence_image gudhi/Persistence_image.h - * \brief A class implementing the Persistence Images. + * \brief A class implementing the persistence images. * * \ingroup Persistence_representations * * \details * + * Persistence images are a way to build images from persistence diagrams. Roughly, the idea is to center Gaussians on each diagram point, with a weight that usually depends on + * the distance to the diagonal, so that the diagram is turned into a function, and then to discretize the plane into pixels, and integrate this function on each pixel. + * See \cite Persistence_Images_2017 for more details. + * **/ class Persistence_image { protected: - PD diagram; - int res_x, res_y; - double min_x, max_x, min_y, max_y; - Weight weight; - double sigma; + Persistence_diagram diagram; + int res_x, res_y; + double min_x, max_x, min_y, max_y; + Weight weight; + double sigma; public: /** \brief Persistence Image constructor. * \ingroup Persistence_image * + * @param[in] _diagram persistence diagram. + * @param[in] _min_x minimum value of pixel abscissa. + * @param[in] _max_x maximum value of pixel abscissa. + * @param[in] _res_x number of pixels for the x-direction. + * @param[in] _min_y minimum value of pixel ordinate. + * @param[in] _max_y maximum value of pixel ordinate. + * @param[in] _res_y number of pixels for the y-direction. + * @param[in] _weight weight function for the Gaussians. + * @param[in] _sigma bandwidth parameter for the Gaussians. + * */ - Persistence_image(PD _diagram, double _min_x = 0.0, double _max_x = 1.0, int _res_x = 10, double _min_y = 0.0, double _max_y = 1.0, int _res_y = 10, - Weight _weight = Gudhi::Persistence_representations::Persistence_weighted_gaussian::arctan_weight(1,1), double _sigma = 1.0){ + Persistence_image(const Persistence_diagram & _diagram, double _min_x = 0.0, double _max_x = 1.0, int _res_x = 10, double _min_y = 0.0, double _max_y = 1.0, int _res_y = 10, const Weight & _weight = arctan_weight(1,1), double _sigma = 1.0){ diagram = _diagram; min_x = _min_x; max_x = _max_x; res_x = _res_x; min_y = _min_y; max_y = _max_y; res_y = _res_y, weight = _weight; sigma = _sigma; } @@ -81,7 +91,7 @@ class Persistence_image { * \ingroup Persistence_image * */ - std::vector<std::vector<double> > vectorize() { + std::vector<std::vector<double> > vectorize() const { std::vector<std::vector<double> > im; for(int i = 0; i < res_y; i++) im.emplace_back(); double step_x = (max_x - min_x)/res_x; double step_y = (max_y - min_y)/res_y; @@ -109,9 +119,8 @@ class Persistence_image { -}; - -} // namespace Persistence_image +}; // class Persistence_image +} // namespace Persistence_representations } // namespace Gudhi #endif // PERSISTENCE_IMAGE_H_ |