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/3461#issuecomment-547626517,https://api.github.com/repos/pydata/xarray/issues/3461,547626517,MDEyOklzc3VlQ29tbWVudDU0NzYyNjUxNw==,5635139,2019-10-29T20:58:36Z,2019-10-29T20:58:36Z,MEMBER,"OK, good points","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547620729,https://api.github.com/repos/pydata/xarray/issues/3461,547620729,MDEyOklzc3VlQ29tbWVudDU0NzYyMDcyOQ==,6213168,2019-10-29T20:43:34Z,2019-10-29T20:43:34Z,MEMBER,I think there's space here to make xarray more user friendly. A better error message would particularly be useful with new xarray users which are used to numpy and pandas - which is the most common new user profile TBH.,"{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547619497,https://api.github.com/repos/pydata/xarray/issues/3461,547619497,MDEyOklzc3VlQ29tbWVudDU0NzYxOTQ5Nw==,3274,2019-10-29T20:40:35Z,2019-10-29T20:40:35Z,CONTRIBUTOR,"I guess so. Minor preference for checking for inappropriate numpy errors like this and giving a better error message, but I can see this would be difficult. This won't be the first bewildering error message problem from `**kwargs`, and it won't be the last. This is a python problem, not an xarray one, per se.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547618326,https://api.github.com/repos/pydata/xarray/issues/3461,547618326,MDEyOklzc3VlQ29tbWVudDU0NzYxODMyNg==,5635139,2019-10-29T20:37:39Z,2019-10-29T20:37:39Z,MEMBER,"I think given we're not in full control of the `sum` function and it's relatively rare to pass `axis`, it's OK to close; is that OK?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547614151,https://api.github.com/repos/pydata/xarray/issues/3461,547614151,MDEyOklzc3VlQ29tbWVudDU0NzYxNDE1MQ==,6213168,2019-10-29T20:27:14Z,2019-10-29T20:33:27Z,MEMBER,"@rpgoldman if you want to do an _elementwise sum_ of the data_vars of a Dataset, it's as simple as ``sum(ds.data_vars.values())``. ``Dataset.sum()`` is not elementwise - it's a reduction along one or more axes - exactly like in numpy.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547614650,https://api.github.com/repos/pydata/xarray/issues/3461,547614650,MDEyOklzc3VlQ29tbWVudDU0NzYxNDY1MA==,3274,2019-10-29T20:28:30Z,2019-10-29T20:28:30Z,CONTRIBUTOR,"@crusaderky Thanks. Yes, that was exactly what I was trying to do.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547614052,https://api.github.com/repos/pydata/xarray/issues/3461,547614052,MDEyOklzc3VlQ29tbWVudDU0NzYxNDA1Mg==,3274,2019-10-29T20:27:00Z,2019-10-29T20:27:00Z,CONTRIBUTOR,"@crusaderky I see what I did wrong. I mistakenly read the documentation page for `DataArray.sum()` instead of `DataSet.sum()`. The former *does* support an `axis` argument, and I believe it makes sense there. Blacklisting these arguments sounds like a great idea, thanks.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547613150,https://api.github.com/repos/pydata/xarray/issues/3461,547613150,MDEyOklzc3VlQ29tbWVudDU0NzYxMzE1MA==,6213168,2019-10-29T20:24:50Z,2019-10-29T20:24:50Z,MEMBER,"It's a case of improper error message. I don't think anybody ever thought of passing the ``axis`` parameter to any of the Dataset methods before. As a general rule, it would be a very unwise idea unless you're sure that *all* of your data_vars have the required dimension exactly in the same position. Note the documentation for Dataset.sum vs. DataArray.sum: http://xarray.pydata.org/en/stable/generated/xarray.Dataset.sum.html http://xarray.pydata.org/en/stable/generated/xarray.DataArray.sum.html You were able to pass the axis parameter because Dataset.sum accepts **kwargs, which are intended for backend-specific arguments (e.g. dask's ``split_every`` parameter). The solution is to blacklist a bunch of numpy arguments that don't make sense (``axis`` is one, but ``out`` also comes to mind).","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547612958,https://api.github.com/repos/pydata/xarray/issues/3461,547612958,MDEyOklzc3VlQ29tbWVudDU0NzYxMjk1OA==,3274,2019-10-29T20:24:25Z,2019-10-29T20:24:25Z,CONTRIBUTOR,"@max-sixty I was trying to sum across the data variables, rather than across a dimension. What I ended up doing was taking the `data` for each of the data variables and adding the resulting numpy arrays. This gave me the sum across the data variables, along the dim (each data variable is one dimensional and they share a single dimension). I'm not sure how to suggest fixing the error message, because I'm not sure what xarray doesn't like.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264 https://github.com/pydata/xarray/issues/3461#issuecomment-547611830,https://api.github.com/repos/pydata/xarray/issues/3461,547611830,MDEyOklzc3VlQ29tbWVudDU0NzYxMTgzMA==,5635139,2019-10-29T20:21:32Z,2019-10-29T20:21:32Z,MEMBER,"It's a bad error message. But the error is correct, I think. Why do you want to use `axis` rather than `dim`? ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,514191264