id,node_id,number,state,locked,title,user,body,created_at,updated_at,closed_at,merged_at,merge_commit_sha,assignee,milestone,draft,head,base,author_association,auto_merge,repo,url,merged_by
343258686,MDExOlB1bGxSZXF1ZXN0MzQzMjU4Njg2,3550,closed,0,cov() and corr() - finalization,45787861,"<!-- Feel free to remove check-list items aren't relevant to your change -->

Dear maintainers, 

this is my first PR and contribution to xarray. I have read the [contributing guidelines](xarray.pydata.org/en/stable/contributing.html) and did my best to conform to your [code of conduct](). However, I would be happy if you have a closer look whether everything is correct and give feedback for improvement!

As I don't have push access to @hrishikeshac's fork, I created this PR to add the final changes for PR #2652.

 - [x] Closes #2652
 - [x] Tests had been added in #2652
 - [ ] Passes `black . && mypy . && flake8`
   - [x] black
   - [x] flake8
   - [ ] mypy
 - [x] Fully documented, including `whats-new.rst` for all changes and `api.rst` for new API
   - [x]  `whats-new.rst`
   - [x] `api.rst`
- [x] example notebook for usage of `corr()` and `cov()`
  - [x] where and how to write the examples?
  - [x] covariance
  - [x] correlation
- [x] moved implementation of cov() and corr() to computation
- [x] add test_cov()
- [x] remove da.cov and da.corr",2019-11-20T09:40:54Z,2020-05-25T16:57:05Z,2020-05-25T16:57:04Z,,cee67b34c3bd0088a7a7e91c8b85644363fa1b34,,,0,4ab4af44bc0835aa4918fdd9dae16e852b3a7962,7466be623fbb4bbb5efc389d31436bd38e53d198,NONE,,13221727,https://github.com/pydata/xarray/pull/3550,