id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
694182591,MDExOlB1bGxSZXF1ZXN0NDgwNTk3OTk3,4407,Dataset.plot.quiver,2448579,closed,0,,,3,2020-09-05T21:04:05Z,2021-02-19T14:21:47Z,2021-02-19T14:21:45Z,MEMBER,,0,pydata/xarray/pulls/4407,"<!-- Feel free to remove check-list items aren't relevant to your change -->

 - [x] Closes #4373 
 - [x] Tests added
 - [x] Passes `isort . && black . && mypy . && flake8`
 - [x] User visible changes (including notable bug fixes) are documented in `whats-new.rst`
 - [x] New functions/methods are listed in `api.rst`

I could use some help with  adding tests and parameter checking if someone wants to help :)

``` python
import numpy as np
import xarray as xr

ds = xr.Dataset()
ds.coords[""x""] = (""x"", np.arange(10))
ds.coords[""y""] = (""y"", np.arange(20))
ds.coords[""t""] = (""t"", np.arange(4))
ds[""u""] = np.sin((ds.x - 5) / 5) * np.sin((ds.y - 10) / 10)
ds[""v""] = np.sin((ds.x - 5) / 5) * np.cos((ds.y - 10) / 10)

ds = ds * 2*np.cos((ds.t) * 2 * 3.14 /0.75)

ds[""u""].attrs[""units""] = ""m/s""
ds[""mag""] = np.hypot(ds.u, ds.v)

ds.mag.plot(col=""t"", x=""x"")

fg = ds.plot.quiver(x=""x"", y=""y"", u=""u"", v=""v"", col=""t"", hue=""mag"")
```

![image](https://user-images.githubusercontent.com/2448579/92313423-38421880-efbb-11ea-8481-7ad956edf3a9.png)
![image](https://user-images.githubusercontent.com/2448579/92313424-3b3d0900-efbb-11ea-9619-8b9dc242e5e6.png)
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