pyicon_calc_xr.py: Fixed a bug where input grid dataset ds_tg was modified by convert_tgrid_data.

pyicon/pyicon_calc_xr.py

@@ -5,13 +5,13 @@ from itertools import product
 
 
 def convert_tgrid_data(
-    ds_tg, check_previous_conversion=True, set_dim_order=None, old_dim_behaviour=None
+    ds_tg_in, check_previous_conversion=True, set_dim_order=None, old_dim_behaviour=None
 ):
     """Convert xarray grid file to grid file compatible with pyicon function.
 
     Parameters
     ----------
-    ds_tg : xr.Dataset
+    ds_tg_in : xr.Dataset
         raw, unprocessed tgrid
 
     check_previous_conversion : bool
@@ -44,6 +44,10 @@ def convert_tgrid_data(
     Then convert by:
     ds_IcD = pyic.convert_tgrid_data(ds_tg)
     """
+
+    # make deep copy of ds_tg_in to avoid glaobal modifications if during this function call
+    ds_tg = ds_tg_in.copy(deep=True)
+
     if old_dim_behaviour is None:
         warnings.warn(
             "The default behaviour for convert_tgrid has recently \
@@ -195,6 +199,7 @@ def convert_tgrid_data(
         ds_IcD[variable] = ds_IcD[variable].rename(dim_name_remappings[variable])
 
     ds_IcD.attrs["converted_tgrid"] = True
+    ds_tg.attrs["converted_tgrid"] = True
 
     if set_dim_order is None:
         standard_order = ["cell", "vertex", "edge", "nc", "nv", "ne", "cart", ...]
@@ -400,8 +405,6 @@ def xr_calc_2dlocal_from_3d(ds_IcD, p_vn_c):
     uo = u2 * cosLon - u1 * sinLon
     vo = -(u1 * cosLon + u2 * sinLon) * sinLat + u3 * cosLat
 
-    uo = u2 * cosLon - u1 * sinLon
-    vo = -(u1 * cosLon + u2 * sinLon) * sinLat + u3 * cosLat
     return uo, vo