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/2304#issuecomment-412495621,https://api.github.com/repos/pydata/xarray/issues/2304,412495621,MDEyOklzc3VlQ29tbWVudDQxMjQ5NTYyMQ==,10050469,2018-08-13T12:04:10Z,2018-08-13T12:04:10Z,MEMBER,"I think we are still talking about different things. In the example by @Thomas-Z above there is still a problem at the line:

```python
# Comparing both dataframes with float32 precision (1e-6)
mask = np.isclose(df_nc['var'], df_xr['var'], rtol=0, atol=1e-6)
```

As discussed several times above, this test is misleading: it should assert for ``atol=0.01``, which is the real accuracy of the underlying data. For this purpose float32 is more than good enough. 

@shoyer said:

> I would be happy to add options for whether to default to float32 or float64 precision.  

so we would welcome a PR in this direction! I don't think we need to change the default behavior though, as there is a slight possibility that some people are relying on the data being float32.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,343659822
https://github.com/pydata/xarray/issues/2304#issuecomment-410680371,https://api.github.com/repos/pydata/xarray/issues/2304,410680371,MDEyOklzc3VlQ29tbWVudDQxMDY4MDM3MQ==,10050469,2018-08-06T11:41:38Z,2018-08-06T11:41:38Z,MEMBER,"> As mentioned in the original issue the modification is straightforward.
> Any ideas if this could be integrated to xarray anytime soon ?

Some people might prefer float32, so it is not as straightforward as it seems. It might be possible to add an option for this, but I didn't look into the details.

> You'll have a float64 in the end but you won't get your precision back

Note that this is a fake sense of precision, because in the example above the compression used is lossy, i.e. precision was lost at compression and the actual precision is now 0.01:

```
short agc_40hz(time, meas_ind) ;
        agc_40hz:_FillValue = 32767s ;
        agc_40hz:units = ""dB"" ;
        agc_40hz:scale_factor = 0.01 ;
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,343659822