Apply set_clip_path to contours, but the set_extend is not work.

[NMC-DAVE]

Hi: I want to clip the contours with shapefile. But with setting the map extent, the figure failed to zoom the region limit. So why? The code is :

def crsmask(shpfilename, region, ax, crs, conf, pathkw = None):
    import cartopy.io.shapereader as shpreader
    from cartopy.mpl.patch import geos_to_path
    from matplotlib.patches import PathPatch
    
    reader = shpreader.Reader(shpfilename)
    countries = reader.records()
    
    try:
        multipoly, = [country.geometry for country in countries
                        if country.attributes['name'] == region]
    except KeyError:
        multipoly, = [country.geometry for country in countries
                        if country.attributes['NAME'] == region]
                        
    main_geom = sorted(multipoly.geoms, key=lambda geom: geom.area)[-1]

    path, = geos_to_path(main_geom)

    plate_carre_data_transform = crs._as_mpl_transform(ax)

    for collection in conf.collections:
        collection.set_clip_path(path, plate_carre_data_transform)
    
    return path

import matplotlib.pyplot as plt
import cartopy.crs as ccrs
import cartopy.io.shapereader as shpreader
from cartopy.examples.waves import sample_data

# subplot_kw 
fig, ax = plt.subplots(subplot_kw=dict(projection=ccrs.PlateCarree()))

ax.set_extent([103., 113, 20, 27.], crs=ccrs.PlateCarree())

plate_carre_data_transform = ccrs.PlateCarree()._as_mpl_transform(ax)

lons, lats, data = sample_data()

con = ax.contourf(lons, lats, data, transform=ccrs.PlateCarree())

shpfilename = shpreader.natural_earth(resolution='10m',
                                      category='cultural',
                                      name='admin_0_countries')

# clip the shapefile polygon                                      
path = crsmask(shpfilename, 'China', ax, ccrs.PlateCarree(), con)

plt.show()

[greglucas]

I think this is because contourf is calling autoscale to readjust the limits after you've set the extent. What happens if you move the ax.set_extent() call just before the show (after the contourf call).

[NMC-DAVE]

I think this is because contourf is calling autoscale to readjust the limits after you've set the extent. What happens if you move the ax.set_extent() call just before the show (after the contourf call).

Hi, greglucas： It's still not work if I 'ax.set_extent' called before the show.

[edwardlikaiyuan]

代主任，可以对每一个被裁切的图元artist，除了进行set_clip_path之外，也要进行set_clip_box(ax.bbox) 或者set(clip_box=ax.bbox)，就可以了 For each artist which should be clipped，add artist.set(clip_box=ax.bbox). 可见视频8:30左右 https://www.bilibili.com/video/BV1Ao4y1N7K8/?spm_id_from=pageDriver&vd_source=4753b17af2eaebe245ddf00b73157cf1