coord_on_land: fix buffer for global grids (#542)

climada/util/coordinates.py

@@ -684,12 +684,10 @@ def coord_on_land(lat, lon, land_geom=None):
         lon_mid = 0.5 * (bounds[0] + bounds[1])
         # normalize lon
         lon_normalize(lons, center=lon_mid)
+        bounds = latlon_bounds(lat, lons, buffer=delta_deg)
         # load land geometry with appropriate same extent
         land_geom = get_land_geometry(
-            extent=(bounds[0] - delta_deg,
-                    bounds[1] + delta_deg,
-                    np.min(lat) - delta_deg,
-                    np.max(lat) + delta_deg),
+            extent=(bounds[0], bounds[2], bounds[1], bounds[3]),
             resolution=10)
     elif not land_geom.is_empty:
         # ensure lon values are within extent of provided land_geom

climada/util/test/test_coordinates.py

@@ -899,13 +899,13 @@ def test_get_land_geometry_all_pass(self):
 
     def test_on_land_pass(self):
         """check point on land with 1:50.000.000 resolution."""
-        lat = np.array([28.203216, 28.555994, 28.860875])
-        lon = np.array([-16.567489, -18.554130, -9.532476])
+        rows, cols, trans = u_coord.pts_to_raster_meta((-179.5, -60, 179.5, 60), (1, -1))
+        xgrid, ygrid = u_coord.raster_to_meshgrid(trans, cols, rows)
+        lat = np.concatenate([[28.203216, 28.555994, 28.860875], ygrid.ravel()])
+        lon = np.concatenate([[-16.567489, -18.554130, -9.532476], xgrid.ravel()])
         res = u_coord.coord_on_land(lat, lon)
-        self.assertEqual(res.size, 3)
-        self.assertTrue(res[0])
-        self.assertFalse(res[1])
-        self.assertTrue(res[2])
+        self.assertEqual(res.size, lat.size)
+        np.testing.assert_array_equal(res[:3], [True, False, True])
 
     def test_dist_to_coast(self):
         """Test point in coast and point not in coast"""