html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/3232#issuecomment-655751621,https://api.github.com/repos/pydata/xarray/issues/3232,655751621,MDEyOklzc3VlQ29tbWVudDY1NTc1MTYyMQ==,13301940,2020-07-08T20:54:15Z,2020-07-08T20:54:15Z,MEMBER,"> @jacobtomlinson gave CuPy a go a few months back. I seem to remember that he ran into a few problems but it would be good to get those documented here.


I've been test driving xarray objects backed by CuPy arrays, and one issue I keep running into is that operations (such as plotting) that expect numpy arrays fail due to xarray's implicit converstion to Numpy arrays via `np.asarray()`. CuPy decided not to allow implicit conversion to NumPy arrays (see https://github.com/cupy/cupy/pull/3421). 

I am wondering whether there is a plan for dealing with this issue?



Here's a small, reproducible example:

```python

[23]: ds.tmin.data.device
      <CUDA Device 0>
[24]: ds.isel(time=0, lev=0).tmin.plot() # Fails
```



<details>
<summary>Traceback</summary>

```python
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-21-69a72de2b9fd> in <module>
----> 1 ds.isel(time=0, lev=0).tmin.plot()

/glade/work/abanihi/softwares/miniconda3/envs/rapids/lib/python3.7/site-packages/xarray/plot/plot.py in __call__(self, **kwargs)
    444 
    445     def __call__(self, **kwargs):
--> 446         return plot(self._da, **kwargs)
    447 
    448     @functools.wraps(hist)

/glade/work/abanihi/softwares/miniconda3/envs/rapids/lib/python3.7/site-packages/xarray/plot/plot.py in plot(darray, row, col, col_wrap, ax, hue, rtol, subplot_kws, **kwargs)
    198     kwargs[""ax""] = ax
    199 
--> 200     return plotfunc(darray, **kwargs)
    201 
    202 

/glade/work/abanihi/softwares/miniconda3/envs/rapids/lib/python3.7/site-packages/xarray/plot/plot.py in newplotfunc(darray, x, y, figsize, size, aspect, ax, row, col, col_wrap, xincrease, yincrease, add_colorbar, add_labels, vmin, vmax, cmap, center, robust, extend, levels, infer_intervals, colors, subplot_kws, cbar_ax, cbar_kwargs, xscale, yscale, xticks, yticks, xlim, ylim, norm, **kwargs)
    684 
    685         # Pass the data as a masked ndarray too
--> 686         zval = darray.to_masked_array(copy=False)
    687 
    688         # Replace pd.Intervals if contained in xval or yval.

/glade/work/abanihi/softwares/miniconda3/envs/rapids/lib/python3.7/site-packages/xarray/core/dataarray.py in to_masked_array(self, copy)
   2325             Masked where invalid values (nan or inf) occur.
   2326         """"""
-> 2327         values = self.values  # only compute lazy arrays once
   2328         isnull = pd.isnull(values)
   2329         return np.ma.MaskedArray(data=values, mask=isnull, copy=copy)

/glade/work/abanihi/softwares/miniconda3/envs/rapids/lib/python3.7/site-packages/xarray/core/dataarray.py in values(self)
    556     def values(self) -> np.ndarray:
    557         """"""The array's data as a numpy.ndarray""""""
--> 558         return self.variable.values
    559 
    560     @values.setter

/glade/work/abanihi/softwares/miniconda3/envs/rapids/lib/python3.7/site-packages/xarray/core/variable.py in values(self)
    444     def values(self):
    445         """"""The variable's data as a numpy.ndarray""""""
--> 446         return _as_array_or_item(self._data)
    447 
    448     @values.setter

/glade/work/abanihi/softwares/miniconda3/envs/rapids/lib/python3.7/site-packages/xarray/core/variable.py in _as_array_or_item(data)
    247     TODO: remove this (replace with np.asarray) once these issues are fixed
    248     """"""
--> 249     data = np.asarray(data)
    250     if data.ndim == 0:
    251         if data.dtype.kind == ""M"":

/glade/work/abanihi/softwares/miniconda3/envs/rapids/lib/python3.7/site-packages/numpy/core/_asarray.py in asarray(a, dtype, order)
     83 
     84     """"""
---> 85     return array(a, dtype, copy=False, order=order)
     86 
     87 

ValueError: object __array__ method not producing an array
```
</details>","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,482543307