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/pull/1517#issuecomment-335316764,https://api.github.com/repos/pydata/xarray/issues/1517,335316764,MDEyOklzc3VlQ29tbWVudDMzNTMxNjc2NA==,1217238,2017-10-09T23:28:52Z,2017-10-09T23:28:52Z,MEMBER,I'll start on my PR to expose this as public API -- hopefully will make some progress on my flight from NY to SF tonight.,"{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,252358450
https://github.com/pydata/xarray/pull/1517#issuecomment-335315831,https://api.github.com/repos/pydata/xarray/issues/1517,335315831,MDEyOklzc3VlQ29tbWVudDMzNTMxNTgzMQ==,1217238,2017-10-09T23:22:33Z,2017-10-09T23:22:33Z,MEMBER,I think this is ready.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,252358450
https://github.com/pydata/xarray/pull/1517#issuecomment-330701517,https://api.github.com/repos/pydata/xarray/issues/1517,330701517,MDEyOklzc3VlQ29tbWVudDMzMDcwMTUxNw==,1217238,2017-09-19T23:25:08Z,2017-09-19T23:25:08Z,MEMBER,"I have a design question here: how should we handle cases where a core dimension exists in multiple chunks? For example, suppose you are applying a function that needs access to every point along the ""time"" axis at once (e.g., an auto-correlation function).
Should we:
1. Automatically rechunk along ""time"" into a single chunk, or
2. Raise an error, and require the user to rechunk manually (xref https://github.com/dask/dask/issues/2689 for API on this)
Currently we do behavior 1, but behavior 2 might be more user friendly. Otherwise it could be pretty easy to inadvertently pass in a dask array (e.g., in small chunks along `time`) that `apply_ufunc` would load into memory by putting in a single chunk.
dask.array has some heuristics to protect against this in `rechunk()` but I'm not sure they are effective enough to catch this. (@mrocklin?)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,252358450
https://github.com/pydata/xarray/pull/1517#issuecomment-330022743,https://api.github.com/repos/pydata/xarray/issues/1517,330022743,MDEyOklzc3VlQ29tbWVudDMzMDAyMjc0Mw==,1217238,2017-09-17T05:39:38Z,2017-09-17T05:39:38Z,MEMBER,"> Alternatively apply_ufunc could see if the func object has a pre_dask_atop method, and apply it if it does.
This seems like a reasonable option to me. Once we get this merged, want to make a PR?
@jhamman could you give this a review? I have not included extensive documentation yet, but I am also reluctant to squeeze that into this PR before we make it public API. (Which I'd like to save for another one.)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,252358450
https://github.com/pydata/xarray/pull/1517#issuecomment-328299112,https://api.github.com/repos/pydata/xarray/issues/1517,328299112,MDEyOklzc3VlQ29tbWVudDMyODI5OTExMg==,1217238,2017-09-09T19:38:09Z,2017-09-09T19:38:09Z,MEMBER,"@nbren12 Probably the best way to do ghosting with the current interface is to write a function that acts on dask array objects to apply the ghosting, and then apply it using `apply_ufunc`. I don't see an easy way to incorporate it into the current interface, which is already getting pretty complicated.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,252358450
https://github.com/pydata/xarray/pull/1517#issuecomment-324734974,https://api.github.com/repos/pydata/xarray/issues/1517,324734974,MDEyOklzc3VlQ29tbWVudDMyNDczNDk3NA==,1217238,2017-08-24T19:34:49Z,2017-08-24T19:34:49Z,MEMBER,@mrocklin I split that discussion off to #1525.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,252358450
https://github.com/pydata/xarray/pull/1517#issuecomment-324732200,https://api.github.com/repos/pydata/xarray/issues/1517,324732200,MDEyOklzc3VlQ29tbWVudDMyNDczMjIwMA==,1217238,2017-08-24T19:22:56Z,2017-08-24T19:22:56Z,MEMBER,"@mrocklin Yes, that took a few seconds (due to hashing the array contents). Would you suggest setting `name=False` by default for xarray's `chunk()` method?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,252358450
https://github.com/pydata/xarray/pull/1517#issuecomment-324705244,https://api.github.com/repos/pydata/xarray/issues/1517,324705244,MDEyOklzc3VlQ29tbWVudDMyNDcwNTI0NA==,1217238,2017-08-24T17:38:29Z,2017-08-24T17:38:29Z,MEMBER,"> What's `rs.randn()`?
Oops, fixed.
> When this makes it into the public facing API it would be nice to include some guidance on how the chunking scheme affects the run time.
We already have some tips here:
http://xarray.pydata.org/en/stable/dask.html#chunking-and-performance
> More ambitiously I could imagine an API such as array1.chunk('place') or array1.chunk('auto') meaning to figure out a reasonable chunking scheme only once .compute() is called so that all the compute steps are known.
Yes, this would be great.
> Maybe this is more specific to dask than xarray. I believe it would also be difficult.
I agree with both!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,252358450