Cartopy: latitude axis gridlines disappear when stand_lon is changed in namelist.wps

Bắt đầu bằng cách tái hiện workflow vẽ Python Cartopy được mô tả trong issue, sử dụng đầu ra của WRF geogrid.exe và namelist.wps với các giá trị stand_lon khác nhau. So sánh nhãn của các đường lưới vĩ độ với các nhãn kinh độ và xác định việc bị cắt xảy ra trong wrf-python hay trong dependency vẽ; hoàn thành khi các nhãn vĩ độ vẫn hiển thị với các thiết lập phép chiếu đã được báo cáo.

Hi!

I was unsure whether to share this on the Cartopy Github page, but because the issue occurs due to a change related to WPS, it seemed appropriate to bring it up here.

I am using Cartopy 0.18.0 to plot out my WRF domains on a map. My process is running geogrid.exe and then executing a Python script that calls Cartopy to create the basemap.

In namelist.wps, I have been toying with the stand_lon variable - I would like it to deviate largely from ref_lon. However, when I set the value to be far enough away from ref_lon, run geogrid.exe, then try to plot the basemap with domain boxes overlaid, the latitude axis labels disappear! I want to have a much higher stand_lon so that my domains exclude higher-level terrain (the Rockies).

I use matplotlib.ticker.FixedLocator (Matplotlib 3.3.2) to add specific y-axis labels, but the issue seems to occur regardless of what tick method I choose. This is a specific issue for the y-axis only, as the longitudes on the x-axis seem fine. I did a test to see the extent of the problem by plotting a bunch of latitudes - and there seems to be a cutoff where Cartopy stops adding axis labels. Strange!

Initial figure: stand_lon = -123.5 = ref_lon

Final figure: stand_lon = -88.5, ref_lon = -123.5

Below are some lines of code connected to this problem.
Thanks so much for your help!

• Anthony

` import cartopy.crs as ccrs
from cartopy.feature import BORDERS, COASTLINE, COLORS, LAKES, NaturalEarthFeature
from matplotlib.ticker import FixedLocator, MultipleLocator
import numpy as np

states = NaturalEarthFeature(category='cultural', scale='50m', name='admin_1_states_provinces_shp', facecolor='none')
ax.add_feature(states, edgecolor='k', linewidth=0.3)
ax.add_feature(COASTLINE, edgecolor='k', linewidth=0.5)
ax.add_feature(LAKES, edgecolor='k', facecolor='none', linewidth=0.5)
ax.add_feature(BORDERS, edgecolor='k', linewidth=0.5)

minlon = int(5*np.ceil(lons[(0,0)]/5))
maxlon = int(5*np.ceil(lons[(0,-1)]/5))
minlat = int(4*np.floor(lats[(0,0)]/4))
maxlat = int(4*np.ceil(lats[(-1,0)]/4))
lonticks = range(minlon,maxlon+1,5)
latticks = range(minlat,maxlat+1,4)

glnolabs = ax.gridlines(crs=ccrs.PlateCarree(), draw_labels=False, linewidth=1.5, linestyle='--')
glnolabs.xlocator = MultipleLocator(base=5)
glnolabs.ylocator = MultipleLocator(base=5)

gl = ax.gridlines(crs=ccrs.PlateCarree(), draw_labels=True, linewidth=1.5, linestyle='--')
gl.top_labels = False
gl.right_labels = False
gl.x_inline = False
gl.y_inline = False
gl.xlocator = FixedLocator(lonticks)
gl.ylocator = FixedLocator([40,41,42,43,44,45,46,47,48,49,50,51,52])

gl.xlabel_style = {'size':lblsz,  'color':'black',  'rotation':0}
gl.ylabel_style = {'size':lblsz,  'color':'black',  'rotation':0}

`