I am relatively new to python and programming and have been trying to make some initial plots of precipitation data for the Indian subcontinent specifically for the indian summer monsoon through the period of June,July,August and September. I have managed to understand some of the code in a tutorial to obtain plot for JJA shown below but failing to modify it suitably to show me season as JJAS instead of JJA. Simply substituting JJAS in place of JJA ofcourse yielded the error
KeyError: 'JJAS'
I have seen one solution to this on the same forum but I am unable to adapt it to my code. I would be extremely grateful if I could receive any advice on this. Thank you !
Below is the code
import xarray as xr
import cartopy.crs as ccrs
import matplotlib.pyplot as plt
import numpy as np
import cmocean
accesscm2_pr_file = r'C:\Users\uSER\Desktop\DissTrack1\ESGF data files\pr_Amon_CAMS-CSM1-0_historical_r1i1p1f1_gn_185001-201412.nc'
dset = xr.open_dataset(accesscm2_pr_file)
clim = dset['pr'].groupby('time.season').mean('time', keep_attrs=True)
clim.data = clim.data * 86400
clim.attrs['units'] = 'mm/day'
fig = plt.figure(figsize=[12,5])
ax = fig.add_subplot(111, projection=ccrs.PlateCarree(central_longitude=180))
clim.sel(season='JJAS').plot.contourf(ax=ax,
levels=np.arange(0, 13.5, 1.5),
extend='max',
transform=ccrs.PlateCarree(),
cbar_kwargs={'label': clim.units},
cmap=cmocean.cm.haline_r)
ax.coastlines()
plt.show()
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
3360 try:
-> 3361 return self._engine.get_loc(casted_key)
3362 except KeyError as err:
~\anaconda3\lib\site-packages\pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()
~\anaconda3\lib\site-packages\pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()
pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
KeyError: 'JJAS'
The above exception was the direct cause of the following exception:
KeyError Traceback (most recent call last)
~\AppData\Local\Temp/ipykernel_16124/3658430410.py in <module>
15 fig = plt.figure(figsize=[12,5])
16 ax = fig.add_subplot(111, projection=ccrs.PlateCarree(central_longitude=180))
---> 17 clim.sel(season='JJAS').plot.contourf(ax=ax,
18 levels=np.arange(0, 13.5, 1.5),
19 extend='max',
~\anaconda3\lib\site-packages\xarray\core\dataarray.py in sel(self, indexers, method, tolerance, drop, **indexers_kwargs)
1269 Dimensions without coordinates: points
1270 """
-> 1271 ds = self._to_temp_dataset().sel(
1272 indexers=indexers,
1273 drop=drop,
~\anaconda3\lib\site-packages\xarray\core\dataset.py in sel(self, indexers, method, tolerance, drop, **indexers_kwargs)
2363 """
2364 indexers = either_dict_or_kwargs(indexers, indexers_kwargs, "sel")
-> 2365 pos_indexers, new_indexes = remap_label_indexers(
2366 self, indexers=indexers, method=method, tolerance=tolerance
2367 )
~\anaconda3\lib\site-packages\xarray\core\coordinates.py in remap_label_indexers(obj, indexers, method, tolerance, **indexers_kwargs)
419 }
420
--> 421 pos_indexers, new_indexes = indexing.remap_label_indexers(
422 obj, v_indexers, method=method, tolerance=tolerance
423 )
~\anaconda3\lib\site-packages\xarray\core\indexing.py in remap_label_indexers(data_obj, indexers, method, tolerance)
272 coords_dtype = data_obj.coords[dim].dtype
273 label = maybe_cast_to_coords_dtype(label, coords_dtype)
--> 274 idxr, new_idx = convert_label_indexer(index, label, dim, method, tolerance)
275 pos_indexers[dim] = idxr
276 if new_idx is not None:
~\anaconda3\lib\site-packages\xarray\core\indexing.py in convert_label_indexer(index, label, index_name, method, tolerance)
189 indexer = index.get_loc(label_value)
190 else:
--> 191 indexer = index.get_loc(label_value, method=method, tolerance=tolerance)
192 elif label.dtype.kind == "b":
193 indexer = label
~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
3361 return self._engine.get_loc(casted_key)
3362 except KeyError as err:
-> 3363 raise KeyError(key) from err
3364
3365 if is_scalar(key) and isna(key) and not self.hasnans:
KeyError: 'JJAS'
Indeed, grouping by "time.season" will only split your data into "DJF", "MAM", "JJA", and "SON". For other combinations of months you will need to define your own mask(s) to apply when taking a mean. For "JJAS" I often use something like this:
jjas = dset.time.dt.month.isin(range(6, 10))
clim = dset.sel(time=jjas).mean("time")