Compute Grid Centerpoint using Welzl's algorithm

test/test_centroids.py

@@ -4,7 +4,8 @@
 import numpy.testing as nt
 import uxarray as ux
 from pathlib import Path
-from uxarray.grid.coordinates import _populate_face_centroids, _populate_edge_centroids, _normalize_xyz
+from uxarray.grid.coordinates import _populate_face_centroids, _populate_edge_centroids, _populate_face_centerpoints
+from uxarray.grid.utils import _normalize_xyz
 
 current_path = Path(os.path.dirname(os.path.realpath(__file__)))
 
@@ -107,3 +108,18 @@ def test_edge_centroids_from_mpas(self):
 
         nt.assert_array_almost_equal(expected_edge_lon, computed_edge_lon)
         nt.assert_array_almost_equal(expected_edge_lat, computed_edge_lat)
+
+    def test_face_centerpoint(self):
+        """Use points from an actual spherical face and get the centerpoint."""
+
+        points = np.array([(-35.26438968, -45.0), (-36.61769496, -42.0), (-33.78769181, -42.0), (-32.48416571, -45.0)])
+        uxgrid = ux.open_grid(points, latlon=True)
+        _populate_face_centerpoints(uxgrid)
+
+        # the expected centerpoint should be close to centroid for this case
+        ctr_lon = uxgrid.face_lon.values[0]
+        ctr_lat = uxgrid.face_lat.values[0]
+
+        # Test the values of the calculated centerpoint, giving high tolerance of one decimal place
+        nt.assert_array_almost_equal(ctr_lon, uxgrid.face_lon_ctrpt.values[0], decimal=1)
+        nt.assert_array_almost_equal(ctr_lat, uxgrid.face_lat_ctrpt.values[0], decimal=1)

test/test_helpers.py

@@ -12,7 +12,7 @@
 from uxarray.grid.connectivity import _replace_fill_values
 from uxarray.constants import INT_DTYPE, INT_FILL_VALUE
 
-from uxarray.grid.coordinates import _lonlat_rad_to_xyz, _normalize_xyz, _xyz_to_lonlat_rad
+from uxarray.grid.utils import _lonlat_rad_to_xyz, _normalize_xyz, _xyz_to_lonlat_rad
 from uxarray.grid.arcs import point_within_gca, _angle_of_2_vectors, in_between
 from uxarray.grid.utils import _get_cartesian_face_edge_nodes, _get_lonlat_rad_face_edge_nodes
 from uxarray.grid.geometry import _pole_point_inside_polygon

uxarray/grid/arcs.py

@@ -2,7 +2,7 @@
 
 # from uxarray.grid.coordinates import node_xyz_to_lonlat_rad, normalize_in_place
 
-from uxarray.grid.coordinates import _xyz_to_lonlat_rad, _normalize_xyz
+from uxarray.grid.utils import _xyz_to_lonlat_rad, _normalize_xyz
 from uxarray.constants import ERROR_TOLERANCE
 
 

uxarray/grid/area.py

@@ -1,6 +1,6 @@
 import numpy as np
 
-from uxarray.grid.coordinates import _lonlat_rad_to_xyz
+from uxarray.grid.utils import _lonlat_rad_to_xyz
 
 from numba import njit, config
 from uxarray.constants import ENABLE_JIT_CACHE, ENABLE_JIT