diff options
Diffstat (limited to 'src/python/gudhi')
| -rw-r--r-- | src/python/gudhi/hera.cc | 71 | ||||
| -rw-r--r-- | src/python/gudhi/wasserstein.py | 6 |
2 files changed, 74 insertions, 3 deletions
diff --git a/src/python/gudhi/hera.cc b/src/python/gudhi/hera.cc new file mode 100644 index 00000000..0d562b4c --- /dev/null +++ b/src/python/gudhi/hera.cc @@ -0,0 +1,71 @@ +/* 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(s): Marc Glisse + * + * Copyright (C) 2020 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#include <pybind11/pybind11.h> +#include <pybind11/numpy.h> + +#include <boost/range/iterator_range.hpp> + +#include <wasserstein.h> // Hera + +#include <array> + +namespace py = pybind11; +typedef py::array_t<double, py::array::c_style | py::array::forcecast> Dgm; + +double wasserstein_distance( + Dgm d1, Dgm d2, + double wasserstein_power, double internal_p, + double delta) +{ + py::buffer_info buf1 = d1.request(); + py::buffer_info buf2 = d2.request(); + // shape (n,2) or (0) for empty + if((buf1.ndim!=2 || buf1.shape[1]!=2) && (buf1.ndim!=1 || buf1.shape[0]!=0)) + throw std::runtime_error("Diagram 1 must be an array of size n x 2"); + if((buf2.ndim!=2 || buf2.shape[1]!=2) && (buf2.ndim!=1 || buf2.shape[0]!=0)) + throw std::runtime_error("Diagram 2 must be an array of size n x 2"); + typedef std::array<double, 2> Point; + auto p1 = (Point*)buf1.ptr; + auto p2 = (Point*)buf2.ptr; + auto diag1 = boost::make_iterator_range(p1, p1+buf1.shape[0]); + auto diag2 = boost::make_iterator_range(p2, p2+buf2.shape[0]); + + hera::AuctionParams<double> params; + params.wasserstein_power = wasserstein_power; + // hera encodes infinity as -1... + if(std::isinf(internal_p)) internal_p = hera::get_infinity<double>(); + params.internal_p = internal_p; + params.delta = delta; + // The extra parameters are purposedly not exposed for now. + return hera::wasserstein_dist(diag1, diag2, params); +} + +PYBIND11_MODULE(hera, m) { + m.def("wasserstein_distance", &wasserstein_distance, + py::arg("X"), py::arg("Y"), + py::arg("order") = 1, + py::arg("internal_p") = std::numeric_limits<double>::infinity(), + py::arg("delta") = .01, + R"pbdoc( + Compute the Wasserstein distance between two diagrams. + Points at infinity are supported. + + Parameters: + X (n x 2 numpy array): First diagram + Y (n x 2 numpy array): Second diagram + order (float): Wasserstein exponent W_q + internal_p (float): Internal Minkowski norm L^p in R^2 + delta (float): Relative error 1+delta + + Returns: + float: Approximate Wasserstein distance W_q(X,Y) + )pbdoc"); +} diff --git a/src/python/gudhi/wasserstein.py b/src/python/gudhi/wasserstein.py index db5ddff2..13102094 100644 --- a/src/python/gudhi/wasserstein.py +++ b/src/python/gudhi/wasserstein.py @@ -27,8 +27,8 @@ def _build_dist_matrix(X, Y, order=2., internal_p=2.): ''' :param X: (n x 2) numpy.array encoding the (points of the) first diagram. :param Y: (m x 2) numpy.array encoding the second diagram. - :param internal_p: Ground metric (i.e. norm l_p). :param order: exponent for the Wasserstein metric. + :param internal_p: Ground metric (i.e. norm L^p). :returns: (n+1) x (m+1) np.array encoding the cost matrix C. For 1 <= i <= n, 1 <= j <= m, C[i,j] encodes the distance between X[i] and Y[j], while C[i, m+1] (resp. C[n+1, j]) encodes the distance (to the p) between X[i] (resp Y[j]) and its orthogonal proj onto the diagonal. note also that C[n+1, m+1] = 0 (it costs nothing to move from the diagonal to the diagonal). @@ -54,8 +54,8 @@ def _build_dist_matrix(X, Y, order=2., internal_p=2.): def _perstot(X, order, internal_p): ''' :param X: (n x 2) numpy.array (points of a given diagram). - :param internal_p: Ground metric on the (upper-half) plane (i.e. norm l_p in R^2); Default value is 2 (Euclidean norm). :param order: exponent for Wasserstein. Default value is 2. + :param internal_p: Ground metric on the (upper-half) plane (i.e. norm L^p in R^2); Default value is 2 (Euclidean norm). :returns: float, the total persistence of the diagram (that is, its distance to the empty diagram). ''' Xdiag = _proj_on_diag(X) @@ -66,8 +66,8 @@ def wasserstein_distance(X, Y, order=2., internal_p=2.): ''' :param X: (n x 2) numpy.array encoding the (finite points of the) first diagram. Must not contain essential points (i.e. with infinite coordinate). :param Y: (m x 2) numpy.array encoding the second diagram. - :param internal_p: Ground metric on the (upper-half) plane (i.e. norm l_p in R^2); Default value is 2 (euclidean norm). :param order: exponent for Wasserstein; Default value is 2. + :param internal_p: Ground metric on the (upper-half) plane (i.e. norm L^p in R^2); Default value is 2 (Euclidean norm). :returns: the Wasserstein distance of order q (1 <= q < infinity) between persistence diagrams with respect to the internal_p-norm as ground metric. :rtype: float ''' |