Add pybinding for writing strahlkorper points

src/NumericalAlgorithms/SphericalHarmonics/Python/Strahlkorper.cpp

@@ -12,8 +12,10 @@
 #include "DataStructures/DataVector.hpp"
 #include "DataStructures/ModalVector.hpp"
 #include "DataStructures/Tensor/Tensor.hpp"
+#include "NumericalAlgorithms/SphericalHarmonics/AngularOrdering.hpp"
 #include "NumericalAlgorithms/SphericalHarmonics/IO/FillYlmLegendAndData.hpp"
 #include "NumericalAlgorithms/SphericalHarmonics/IO/ReadSurfaceYlm.hpp"
+#include "NumericalAlgorithms/SphericalHarmonics/IO/StrahlkorperCoordsToTextFile.hpp"
 #include "NumericalAlgorithms/SphericalHarmonics/Strahlkorper.hpp"
 
 namespace py = pybind11;
@@ -79,5 +81,20 @@ void bind_strahlkorper(pybind11::module& m) {  // NOLINT
         &ylm::read_surface_ylm_single_time<Frame::Inertial>,
         py::arg("file_name"), py::arg("surface_subfile_name"), py::arg("time"),
         py::arg("relative_epsilon"), py::arg("check_frame"));
+  py::enum_<ylm::AngularOrdering>(m, "AngularOrdering")
+      .value("Strahlkorper", ylm::AngularOrdering::Strahlkorper)
+      .value("Cce", ylm::AngularOrdering::Cce);
+  m.def(
+      "write_sphere_of_points_to_text_file",
+      [](const double radius, const size_t l_max,
+         const std::array<double, 3>& center,
+         const std::string& output_file_name,
+         const ylm::AngularOrdering ordering, const bool overwrite_file) {
+        ylm::write_strahlkorper_coords_to_text_file(
+            radius, l_max, center, output_file_name, ordering, overwrite_file);
+      },
+      py::arg("radius"), py::arg("l_max"), py::arg("center"),
+      py::arg("output_file_name"), py::arg("ordering"),
+      py::arg("overwrite_file") = false);
 }
 }  // namespace ylm::py_bindings

tests/Unit/NumericalAlgorithms/SphericalHarmonics/Python/Test_Strahlkorper.py

@@ -11,10 +11,12 @@
 import spectre.Informer as spectre_informer
 import spectre.IO.H5 as spectre_h5
 from spectre.SphericalHarmonics import (
+    AngularOrdering,
     Strahlkorper,
     cartesian_coords,
     read_surface_ylm,
     read_surface_ylm_single_time,
+    write_sphere_of_points_to_text_file,
     ylm_legend_and_data,
 )
 
@@ -26,6 +28,9 @@ def setUp(self):
             "NumericalAlgorithms/Strahlkorper/Python",
         )
         self.filename = os.path.join(self.test_dir, "Strahlkorper.h5")
+        self.text_filename = os.path.join(
+            self.test_dir, "PyStrahlkorperCoords.txt"
+        )
         shutil.rmtree(self.test_dir, ignore_errors=True)
         os.makedirs(self.test_dir, exist_ok=True)
 
@@ -80,6 +85,44 @@ def test_strahlkorper(self):
             strahlkorper,
         )
 
+        l_max = 4
+        print("hello")
+        # First write with wrong l_max
+        write_sphere_of_points_to_text_file(
+            radius=1.2,
+            l_max=l_max - 1,
+            center=[-0.1, -0.2, -0.3],
+            output_file_name=self.text_filename,
+            ordering=AngularOrdering.Cce,
+        )
+        # Test that if overwrite_file = False (the default) an exception is
+        # raised
+        self.assertRaises(
+            RuntimeError,
+            write_sphere_of_points_to_text_file,
+            radius=1.2,
+            l_max=l_max - 1,
+            center=[-0.1, -0.2, -0.3],
+            output_file_name=self.text_filename,
+            ordering=AngularOrdering.Cce,
+        )
+        # Finally write the correct l_max so we can check that overwrite_file
+        # works
+        write_sphere_of_points_to_text_file(
+            radius=1.2,
+            l_max=l_max,
+            center=[-0.1, -0.2, -0.3],
+            output_file_name=self.text_filename,
+            ordering=AngularOrdering.Cce,
+            overwrite_file=True,
+        )
+
+        with open(self.text_filename, "r") as text_file:
+            # Physical size of ylm::Spherepack
+            num_points = (l_max + 1) * (2 * l_max + 1)
+            all_lines = text_file.readlines()
+            self.assertEqual(num_points, len(all_lines))
+
 
 if __name__ == "__main__":
     unittest.main(verbosity=2)