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/1989#issuecomment-373221321,https://api.github.com/repos/pydata/xarray/issues/1989,373221321,MDEyOklzc3VlQ29tbWVudDM3MzIyMTMyMQ==,1828519,2018-03-15T00:37:26Z,2018-03-15T00:38:04Z,CONTRIBUTOR,@shoyer In my examples `rows = cols = 1000` (xarray 0.10.1).,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,305373563
https://github.com/pydata/xarray/issues/1989#issuecomment-373219624,https://api.github.com/repos/pydata/xarray/issues/1989,373219624,MDEyOklzc3VlQ29tbWVudDM3MzIxOTYyNA==,1828519,2018-03-15T00:27:35Z,2018-03-15T00:27:35Z,CONTRIBUTOR,"Example:

```
import numpy as np
import xarray as xr
a = xr.DataArray(np.random.random((rows, cols)).astype(np.float32), dims=('y', 'x'))
In [65]: np.sum(a).data
Out[65]: array(499858.0625)

In [66]: np.sum(a.data)
Out[66]: 499855.19

In [67]: np.sum(a.data.astype(np.float64))
Out[67]: 499855.21635645436

In [68]: np.sum(a.data.astype(np.float32))
Out[68]: 499855.19
```

I realized after making this example that nansum gives expected results:
```
a = xr.DataArray(np.random.random((rows, cols)).astype(np.float32), dims=('y', 'x'))
In [83]: np.nansum(a.data)
Out[83]: 500027.81

In [84]: np.nansum(a)
Out[84]: 500027.81

In [85]: np.nansum(a.data.astype(np.float64))
Out[85]: 500027.77103802469

In [86]: np.nansum(a.astype(np.float64))
Out[86]: 500027.77103802469
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,305373563