Using cf_xarray to infer attributes

cmip6_preprocessing/preprocessing.py

@@ -68,6 +68,10 @@ def _invert_dict(rdict):
  return exploded_dict
 
 
+def _parse_cf(dataset):
+ dataset = dataset.cf.guess_coord_axis()
+ return dataset
+
 def rename_cmip6(ds, rename_dict=None):
  """Homogenizes cmip6 dataasets to common naming"""
  ds = ds.copy()
@@ -109,6 +113,8 @@ def _maybe_rename(obj, rdict):
  # restore attributes
  ds.attrs = attrs
 
+ # use cf conventions where they can be inferred by cf_xarray
+ ds = _parse_cf(ds)
  return ds
 
 

tests/test_preprocessing.py

@@ -66,6 +66,12 @@ def test_rename_cmip6(xname, yname, zname, missing_dim):
  assert ylen == len(ds_renamed.y)
  if not missing_dim == "z":
  assert zlen == len(ds_renamed.lev)
+
+ # check if cf conventions were inferred
+ for dim, axis in [('x', 'X'), ('y', 'Y'), ('lev','Z'), ('time', 'T')]:
+ if dim in ds_renamed.dims:
+ #check that the axis is in the cf object
+ assert axis in ds_renamed.cf.axes.keys()
 
 
 @pytest.mark.parametrize("xname", ["i", "x"])

tests/test_preprocessing_cloud.py

@@ -236,6 +236,12 @@ def test_check_dim_coord_values_wo_intake(
  if unit:
  assert unit == expected_unit
 
+ # check if cf conventions were inferred
+ for dim, axis in [('x', 'X'), ('y', 'Y'), ('lev','Z'), ('time', 'T')]:
+ if dim in ds.dims:
+ #check that the axis is in the cf object
+ assert axis in ds.cf.axes.keys()
+
 
 # this fixture has to be redifined every time to account for different fail cases for each test
 @pytest.fixture