Improve fieldset error message on missing axis metadata

VeckoTheGecko · VeckoTheGecko · commit caab3f2a9f1c · 2025-10-23T16:17:35.000+02:00
diff --git a/src/parcels/_core/fieldset.py b/src/parcels/_core/fieldset.py
@@ -204,7 +204,7 @@ def from_copernicusmarine(ds: xr.Dataset):
         expected_axes = set("XYZT")  # TODO: Update after we have support for 2D spatial fields
         if missing_axes := (expected_axes - set(ds.cf.axes)):
             raise ValueError(
-                f"Dataset missing axes {missing_axes} to have coordinates for all {expected_axes} axes according to CF conventions."
+                f"Dataset missing metadata for axes {missing_axes} to have coordinates for all {expected_axes} axes according to CF conventions. HINT: Add metadata attribute axis - e.g., ds['lat'].attrs['axis'] = 'Y'"
             )
 
         ds = _rename_coords_copernicusmarine(ds)

Original file line number	Diff line number	Diff line change
`@@ -204,7 +204,7 @@ def from_copernicusmarine(ds: xr.Dataset):`
`204`	`204`	`expected_axes = set("XYZT") # TODO: Update after we have support for 2D spatial fields`
`205`	`205`	`if missing_axes := (expected_axes - set(ds.cf.axes)):`
`206`	`206`	`raise ValueError(`
`207`		`- f"Dataset missing axes {missing_axes} to have coordinates for all {expected_axes} axes according to CF conventions."`
	`207`	`+ f"Dataset missing metadata for axes {missing_axes} to have coordinates for all {expected_axes} axes according to CF conventions. HINT: Add metadata attribute axis - e.g., ds['lat'].attrs['axis'] = 'Y'"`
`208`	`208`	`)`
`209`	`209`
`210`	`210`	`ds = _rename_coords_copernicusmarine(ds)`