Trouble with sortby()

[kingkong-cmd]

I'm getting an error when trying to reorder a grib file from NOAA to make it work with openlayers. Since the raw file comes with 0 to 360 lons, I just minus 180 from the lons above 180. This works fine, but I want to reorder so that the data now goes from -180 to 180.

However, when I try ds.sortby('logintude') I get AttributeError: 'GribberishBackendArray' object has no attribute 'oindex'. Same if i try to sort by latitude. Am I doing something wrong?

Python code to reproduce:

import xarray as xr
input_grib_filename = 'tmp/grib/2024082912/12/1p00/2024082912_1p00_f000.grb'
ds = xr.open_dataset(input_grib_filename, engine='gribberish')
ds.coords['longitude'] = (ds.coords['longitude'] + 180) % 360 - 180
ds.sortby('longitude')

Content of ds after -180 operation:

<xarray.Dataset> Size: 1MB
Dimensions:    (time: 1, latitude: 181, longitude: 360)
Coordinates:
  * time       (time) datetime64[ns] 8B 2024-08-29T12:00:00
  * latitude   (latitude) float64 1kB 90.0 89.0 88.0 87.0 ... -88.0 -89.0 -90.0
  * longitude  (longitude) float64 3kB 0.0 1.0 2.0 3.0 ... -4.0 -3.0 -2.0 -1.0
Data variables:
    ugrd       (time, latitude, longitude) float64 521kB ...
    vgrd       (time, latitude, longitude) float64 521kB ...
Attributes:
    meta:     Generated with gribberishpy

Error trace

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/venv/lib/python3.10/site-packages/xarray/core/dataset.py", line 8023, in sortby
    return aligned_self.isel(indices)
  File "/venv/lib/python3.10/site-packages/xarray/core/dataset.py", line 2963, in isel
    var = var.isel(var_indexers)
  File "/venv/lib/python3.10/site-packages/xarray/core/variable.py", line 1018, in isel
    return self[key]
  File "/venv/lib/python3.10/site-packages/xarray/core/variable.py", line 785, in __getitem__
    data = indexing.apply_indexer(indexable, indexer)
  File "/venv/lib/python3.10/site-packages/xarray/core/indexing.py", line 1000, in apply_indexer
    return indexable.oindex[indexer]
  File "/venv/lib/python3.10/site-packages/xarray/core/indexing.py", line 342, in __getitem__
    return self.getter(key)
  File "/venv/lib/python3.10/site-packages/xarray/core/indexing.py", line 813, in _oindex_get
    return type(self)(_wrap_numpy_scalars(self.array.oindex[indexer]))
  File "/venv/lib/python3.10/site-packages/xarray/core/indexing.py", line 342, in __getitem__
    return self.getter(key)
  File "/venv/lib/python3.10/site-packages/xarray/core/indexing.py", line 763, in _oindex_get
    return type(self)(_wrap_numpy_scalars(self.array.oindex[indexer]))
AttributeError: 'GribberishBackendArray' object has no attribute 'oindex'

[mpiannucci]

I think an index is missing from the gribberish python code. Can you send me a link to the grib file you're working with?

[kingkong-cmd]

I think an index is missing from the gribberish python code. Can you send me a link to the grib file you're working with?

Sure! See below:

https://nomads.ncep.noaa.gov/cgi-bin/filter_gfs_1p00.pl?&dir=/gfs.20240901/12/atmos&file=gfs.t12z.pgrb2.1p00.f000&var_UGRD=on&var_VGRD=on&lev_10_m_above_ground=on

I also tried the reindex(). It suddenly worked, but then it suddenly didn't again, with the same error as sortby().

[mpiannucci]

Should be fixed with main branch or with version 0.20.2 which is building for release now :) .. Lemme know if you still run into issues!

[kingkong-cmd]

Should be fixed with main branch or with version 0.20.2 which is building for release now :) .. Lemme know if you still run into issues!

Wow, works perfectly! Thank you! And thanks for making this lib.

<xarray.Dataset> Size: 17MB
Dimensions:    (time: 1, latitude: 721, longitude: 1440)
Coordinates:
  * time       (time) datetime64[ns] 8B 2024-09-03T16:00:00
  * latitude   (latitude) float64 6kB 90.0 89.75 89.5 ... -89.5 -89.75 -90.0
  * longitude  (longitude) float64 12kB -179.8 -179.5 -179.2 ... 179.8 180.0
Data variables:
    vgrd       (time, latitude, longitude) float64 8MB -5.648 -5.638 ... 3.722
    ugrd       (time, latitude, longitude) float64 8MB -2.235 -2.265 ... 4.795
Attributes:
    meta:     Generated with gribberishpy