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/4482#issuecomment-708088129,https://api.github.com/repos/pydata/xarray/issues/4482,708088129,MDEyOklzc3VlQ29tbWVudDcwODA4ODEyOQ==,5635139,2020-10-14T00:50:40Z,2020-10-14T00:50:40Z,MEMBER,"Right — that makes sense now. Given that `.fillna(0)` creates a copy,  when we're doing stride tricks in the form of `construct` then that copy can be huge.

So I think there's a spectrum of implementations of `skipna`, o/w two are:
- as a convenient alias of `.fillna(0)`, like @mathause 's [example above](https://github.com/pydata/xarray/issues/4482#issuecomment-702965721) IIUC
- ensuring a copy isn't made, which may require diving into `np.einops` (or open to alternatives)

The second would be required for @heerad 's case above","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,713834297
https://github.com/pydata/xarray/issues/4482#issuecomment-706442785,https://api.github.com/repos/pydata/xarray/issues/4482,706442785,MDEyOklzc3VlQ29tbWVudDcwNjQ0Mjc4NQ==,5635139,2020-10-09T23:29:23Z,2020-10-09T23:29:23Z,MEMBER,"Maybe on very small arrays it's quicker to do a product than a copy? As the array scales, it's surely not — dot product is O(n^3) or similar. I would be interested to see a repro...","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,713834297
https://github.com/pydata/xarray/issues/4482#issuecomment-704634447,https://api.github.com/repos/pydata/xarray/issues/4482,704634447,MDEyOklzc3VlQ29tbWVudDcwNDYzNDQ0Nw==,5635139,2020-10-07T01:12:09Z,2020-10-07T01:12:09Z,MEMBER,"Any idea why `x.fillna(0.)` is so much more expensive than `x.dot(y)`? 

For some functions where `fillna(0.)` has a different result to `skipna=True`, I could see it being worthwhile to writing new routines. But for dot product, it's definitionally the same. And `fillna` seems a much simpler operation than `dot`...","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,713834297
https://github.com/pydata/xarray/issues/4482#issuecomment-702937094,https://api.github.com/repos/pydata/xarray/issues/4482,702937094,MDEyOklzc3VlQ29tbWVudDcwMjkzNzA5NA==,5635139,2020-10-02T20:13:37Z,2020-10-02T20:13:37Z,MEMBER,"I agree this would be a welcome option.

As a workaround, you could fillna with zero?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,713834297