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/4465#issuecomment-699550315,https://api.github.com/repos/pydata/xarray/issues/4465,699550315,MDEyOklzc3VlQ29tbWVudDY5OTU1MDMxNQ==,1217238,2020-09-26T21:30:35Z,2020-09-26T21:30:35Z,MEMBER,"I would suggest only specifying `tolerance` as an absolute tolerance, which would match the argument name we have on the `.sel()` method.

Is there a case where you think `rtol` would be much better, or would let you do something that isn't possible with an absolute tolerance?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709503596
https://github.com/pydata/xarray/issues/4465#issuecomment-699548837,https://api.github.com/repos/pydata/xarray/issues/4465,699548837,MDEyOklzc3VlQ29tbWVudDY5OTU0ODgzNw==,10563614,2020-09-26T21:15:44Z,2020-09-26T21:15:44Z,CONTRIBUTOR,"Interesting discussion #2217. As far as I understand, it solves a wider problem than using a tolerance on and a member by member comparison... but more complex to implement.

Here is the simple solution that works for me (combine.py:70):

            if not (all(index.equals(indexes[0]) for index in indexes[1:])
                    or (tolerance > 0 and \
                        all(index.is_numeric() for index in indexes) and \
                        all(np.allclose(index, indexes[0], atol=tolerance, rtol=0) for index in indexes[1:]))):

I've not tested in depth, I can make a PR, tests, doc if you agree with this solution.

Regarding the name of the arg. ""tolerance"" is nice, but allclose has atol and rtol. My solution above only set atol, but both may be useful. Should we use:
2args: atol, rtol
2 args: atolerance, rtolerance
1 args:  tolerance could be a number (->atol) or a tuple interpreted as atol, rtol = tolerance 
or a dict
.... ?


","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709503596
https://github.com/pydata/xarray/issues/4465#issuecomment-699523381,https://api.github.com/repos/pydata/xarray/issues/4465,699523381,MDEyOklzc3VlQ29tbWVudDY5OTUyMzM4MQ==,1217238,2020-09-26T17:20:25Z,2020-09-26T17:20:25Z,MEMBER,"See https://github.com/pydata/xarray/issues/2217 for related discussion about adding a `tolerance` parameter to alignment.

I think adding a `tolerance` parameter would be a welcome addition. It's not commutative, which is a little inelegant, but it's definitely a strict improvement over `join='override'`.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709503596
https://github.com/pydata/xarray/issues/4465#issuecomment-699498941,https://api.github.com/repos/pydata/xarray/issues/4465,699498941,MDEyOklzc3VlQ29tbWVudDY5OTQ5ODk0MQ==,2448579,2020-09-26T13:58:08Z,2020-09-26T13:58:08Z,MEMBER,"You can totally skip this comparison by specifying `join=""override""` (since `lat`, `lon` are ""indexes""; the join kwarg controls how they are aligned; override will skip the comparison and just use the `lat` or `lon` from the first dataset).

Adding `tolerance` seems OK to me.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709503596