issue_comments: 565186199

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https://github.com/pydata/xarray/issues/3574#issuecomment-565186199 https://api.github.com/repos/pydata/xarray/issues/3574 565186199 MDEyOklzc3VlQ29tbWVudDU2NTE4NjE5OQ== 941907 2019-12-12T21:04:33Z 2019-12-12T21:04:33Z NONE

The problem is that Dask, as of version 2.0, calls functions applied to dask arrays with size zero inputs, to figure out the output array type, e.g., is the output a dense numpy.ndarray or a sparse array?

Yes, now I recall that this was the issue, yeah. It doesn't even depend on your actual data really.

Possible option 3. is to address https://github.com/dask/dask/issues/5642 directly (haven't found time to do a PR yet). Essentially from the code described in that issue I have the feeling that if a dtype is passed (as apply_ufunc does), then meta should not need to be calculated.

 
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