Add some support for X-Array in a staged manner.

[scollis]

trafficstars

Creating a Checklist so we can keep track of this:

• [x] Add an xradar branch to develop/test on
• [x] Add helper functions to convert to an xradar object (#1251 )
• [ ] Move aux_io readers to xradar
• [ ] Implement a radar.to_xradar() method
• [x] Add a separate xradar object, similar to the radar object, that we can feed metadata + values directly into

[tjlang]

Did someone say cartopy support for grids? Y'all already got that. Here's a plot with multiple NEXRADs mosaicked via Py-ART, visualizing an ISS overpass of thunderstorms near San Antonio, Austin, and College Station (red stars) on 1/2/2017. Base map provided by cartopy and its StamenTerrain tiling. Was like two lines to get the radar on there, using Grid's method to get lat/lons, then a pcolormesh call.

[scollis]

Yep.. But it is one line if you have it in an xarray container :) Sweet plot.

[zssherman]

Xarray was added to grid routine, but not the radardisplay. Xarry was also used in the spectra object. I will leave this open for now .

[mgrover1]

Coming back to this thread - we should like this to Discussion #1047