[Bug] GeoAxes extent got messed up.

[gepcel]

import ultraplot as pplt
import cartopy.crs as ccrs
fig, ax = pplt.subplot(proj='cyl')
ax.format(lonlim=[0.73, 1.92], latlim=[0.81, 1.97])
print("After set extent using lonlim and latlim:",ax.get_extent())
ax.set_extent([0.73, 1.92, 0.81, 1.97], crs=ccrs.PlateCarree())
print("After set extent using set_extent       :",ax.get_extent())
ax.format(lonlines=.4, latlines=.4, ticklen=0.5)
print("After format something other than extent:",ax.get_extent())

Got result as:

After set extent using lonlim and latlim: (0.22999999999999998, 2.42, 0.31000000000000005, 2.4699999999999998)
After set extent using set_extent       : (0.73, 1.92, 0.81, 1.97)
After format something other than extent: (0.22999999999999998, 2.42, 0.31000000000000005, 2.4699999999999998)

environments:
ultraplot: latest branch with add-chord-diagram i think
cartopy: 0.25.0
matplotlib: 3.10.7

[cvanelteren]

Not sure if this is a bug. The format method automatically applies 0.5 on either of the extent to allow for the labels to fit nicely -- this does not happen for the set_extent method. which is the discrepancy you are seeing here.

[cvanelteren]

But it is rather confusing so I guess we align the two methods by not adding the padding when users are setting the boundaries explicitly.

[gepcel]

I saw the pr, according to the doc:

lonlim, latlim (2-tuple of float, optional) – For cartopy axes only. The approximate
longitude and latitude boundaries of the map, applied with set_extent. When basemap
is the backend this argument must be passed to Proj instead.

Shouldn't ax.format(lonlim=(x1, x2), latlim=(y1, y2) equals to ax.set_extent(x1, x2, y1, y2)?