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Diffstat (limited to 'src/python/gudhi/hera.cc')
-rw-r--r-- | src/python/gudhi/hera.cc | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/src/python/gudhi/hera.cc b/src/python/gudhi/hera.cc new file mode 100644 index 00000000..61f0da10 --- /dev/null +++ b/src/python/gudhi/hera.cc @@ -0,0 +1,62 @@ +#include <pybind11/pybind11.h> +#include <pybind11/numpy.h> + +#include <boost/range/iterator_range.hpp> + +#include <wasserstein.h> + +#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"), + // Should we name those q, p and d instead? + 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"); +} |