"Unknown unit group: dimensionless"-error with DTU23

[torbjoernt]

Hi, I was trying to calculate predictions with the DTU23-model, but it fails on open_dataset. For example, with the code

import pyTMD
modelfolder = '/path/to/modelfiles/'
dtu = pyTMD.io.model(modelfolder).from_database('DTU23')
dtu_ds = dtu.open_dataset(group='z')

I get the error

ValueError                                Traceback (most recent call last)
Cell In[3], line 3
      1 dtu = pyTMD.io.model(modeldir).from_database('DTU23')
      2 # # read model as xarray Dataset
----> 3 dtu_ds = dtu.open_dataset(group='z')

File [~\AppData\Roaming\Python\Python312\site-packages\pyTMD\io\model.py:843](...~/AppData/Roaming/Python/Python312/site-packages/pyTMD/io/model.py#line=842), in model.open_dataset(self, **kwargs)
    841 # convert to default units
    842 if kwargs["use_default_units"]:
--> 843     ds = ds.tmd.to_default_units()
    844 # return xarray dataset
    845 return ds

File [~\AppData\Roaming\Python\Python312\site-packages\pyTMD\io\dataset.py:759](...~/AppData/Roaming/Python/Python312/site-packages/pyTMD/io/dataset.py#line=758), in Dataset.to_default_units(self)
    757 # convert each constituent in the dataset
    758 for c in self.constituents:
--> 759     ds[c] = ds[c].tmd.to_default_units()
    760 # return the dataset
    761 return ds

File [~\AppData\Roaming\Python\Python312\site-packages\pyTMD\io\dataset.py:892]...~/AppData/Roaming/Python/Python312/site-packages/pyTMD/io/dataset.py#line=891), in DataArray.to_default_units(self, value)
    884 """Convert ``DataArray`` to default tide units
    885 
    886 Parameters
   (...)    889     scaling factor to apply
    890 """
    891 # convert to default units
--> 892 default_units = _default_units.get(self.group, self.units)
    893 da = self.to_units(default_units, value=value)
    894 return da

File [~\AppData\Roaming\Python\Python312\site-packages\pyTMD\io\dataset.py:916](...~/AppData/Roaming/Python/Python312/site-packages/pyTMD/io/dataset.py#line=915), in DataArray.group(self)
    914     return "transport"
    915 else:
--> 916     raise ValueError(f"Unknown unit group: {self.units}")

ValueError: Unknown unit group: dimensionless

Has anyone else experienced the same? I'm on version 3.0.2 of pyTMD.

[tsutterley]

That's totally weird and definitely an issue! I'll track it down and get a fix in 👍

Thanks!!

[tsutterley]

Should (hopefully) be fixed in version 3.0.3!

[torbjoernt]

Seems so, thanks! Haven't checked the results any further, but the error is gone, and I did get a prediction 👍

On another note, I see there is also a FutureWarning from xarray:

...Python/Python312/site-packages/pyTMD/io/GOT.py#line=127): FutureWarning: In a future version of xarray the
default value for join will change from join='outer' to join='exact'. This change will result in the following
ValueError: cannot be aligned with join='exact' because index/labels/sizes are not equal along these coordinates
(dimensions): 'x' ('x',) The recommendation is to set join explicitly for this case.
  ds = xr.merge(d, compat="override")

[tsutterley]

I'll make that change! Thanks!