Store grid mapping on metpy_crs coord rather than DataArray attrs

Unidata · Aug 30, 2021 · 260e541 · 260e541
1 parent e6786f8
commit 260e541
Show file tree

Hide file tree

Showing 2 changed files with 28 additions and 2 deletions.
diff --git a/src/metpy/io/gempak.py b/src/metpy/io/gempak.py
@@ -25,6 +25,7 @@
                     specific_humidity_from_dewpoint, thickness_hydrostatic,
                     virtual_temperature)
 from ..package_tools import Exporter
+from ..plots.mapping import CFProjection
 from ..units import units
 
 exporter = Exporter(globals())
@@ -1270,12 +1271,12 @@ def gdxarray(self, parameter=None, date_time=None, coordinate=None,
                             gvcord: [col_head.GLV1],
                             'x': self.x,
                             'y': self.y,
+                            'metpy_crs': CFProjection(self.crs.to_cf())
                         },
                         dims=['time', gvcord, 'y', 'x'],
                         name=var,
                         attrs={
-                            **self.crs.to_cf(),
-                            'grid_type': ftype,
+                            'gempak_grid_type': ftype,
                         }
                     )
                     grids.append(xrda)

diff --git a/tests/io/test_gempak.py b/tests/io/test_gempak.py
@@ -225,3 +225,28 @@ def test_coordinates_creation(proj_type):
 
     assert_allclose(decode_lat, true_lat, rtol=1e-6, atol=1e-2)
     assert_allclose(decode_lon, true_lon, rtol=1e-6, atol=1e-2)
+
+
+@pytest.mark.parametrize('proj_type, proj_attrs', [
+    ('conical', {
+        'grid_mapping_name': 'lambert_conformal_conic',
+        'standard_parallel': (25.0, 25.0),
+        'latitude_of_projection_origin': 0.0,
+        'longitude_of_central_meridian': -95.0,
+        'semi_major_axis': 6371200.,
+        'semi_minor_axis': 6371200.,
+    }),
+    ('azimuthal', {
+        'grid_mapping_name': 'polar_stereographic',
+        'latitude_of_projection_origin': 90.0,
+        'straight_vertical_longitude_from_pole': -105.0,
+        'scale_factor_at_projection_origin': 1.0,
+        'semi_major_axis': 6371200.,
+        'semi_minor_axis': 6371200.,
+    })
+])
+def test_metpy_crs_creation(proj_type, proj_attrs):
+    grid = GempakGrid(get_test_data(f'gem_{proj_type}.grd'))
+    metpy_crs = grid.gdxarray()[0].metpy.crs
+    for k, v in proj_attrs.items():
+        assert metpy_crs[k] == v