Add random points generator on sphere in python, with an example

1 files changed, 68 insertions, 0 deletions

diff --git a/src/python/gudhi/random_point_generators.cc b/src/python/gudhi/random_point_generators.cc
new file mode 100644
index 00000000..39b09a6d
--- /dev/null
+++ b/src/python/gudhi/random_point_generators.cc
@@ -0,0 +1,68 @@
+/*    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):       Hind Montassif
+ *
+ *    Copyright (C) 2021 Inria
+ *
+ *    Modification(s):
+ *      - YYYY/MM Author: Description of the modification
+ */
+
+#include <pybind11/pybind11.h>
+#include <pybind11/numpy.h>
+
+#include <gudhi/random_point_generators.h>
+
+#include <CGAL/Epick_d.h>
+
+namespace py = pybind11;
+
+
+typedef CGAL::Epick_d< CGAL::Dynamic_dimension_tag > Kern;
+
+template <typename Kernel>
+py::array_t<double> generate_points_on_sphere(py::object num_points, py::object dim, py::object radius) {
+    int npoints = num_points.cast<int>();
+    int d = dim.cast<int>();
+    double rad  = radius.cast<double>();
+    
+    py::gil_scoped_release release;
+
+    auto points_generated = Gudhi::generate_points_on_sphere_d<Kernel>(npoints, d, rad);
+    
+    py::gil_scoped_acquire acquire;
+    
+    py::array_t<double> points({npoints, d});
+ 
+    py::buffer_info buf = points.request();
+
+    double *ptr = static_cast<double *>(buf.ptr);
+
+    assert(npoints == buf.shape[0]);
+    assert(d == buf.shape[1]);
+    
+
+    for (size_t i = 0; i < (size_t)npoints; i++)
+        for (size_t j = 0; j < (size_t)d; j++)
+            ptr[i*d+j] = points_generated.at(i).at(j);
+
+    return points;
+}
+
+PYBIND11_MODULE(random_point_generators, m) {
+      m.attr("__license__") = "LGPL v3";
+      m.def("generate_points_on_sphere_d", &generate_points_on_sphere<Kern>,
+          py::arg("num_points"), py::arg("dim"), py::arg("radius"),
+          R"pbdoc(
+    Generate points on a sphere
+
+    :param num_points: The number of points to be generated.
+    :type num_points: integer
+    :param dim: The sphere dimension.
+    :type dim: integer
+    :param radius: The sphere radius.
+    :type radius: float
+    :rtype: numpy array of points
+    :returns: the generated points on a sphere.
+    )pbdoc");
+}