Zoom into specific region of cartopy projection

I’m getting an error with proplot when trying to zoom in to a specific subregion of my cartopy projection. I just want to map the California coastline, but it seems to break due to changes in the axis width. However, this works just fine with matplotlib.

Any tips here? Should I be using something other than set_extent that I can call in plot.subplots()? Any thoughts on maintaining the right width/aspect for a zoomed in cartopy subplot? I’ve had trouble in the past with matplotlib to get differing coastal regions to have the same width/height aspect ratio due to being in different latitudes.

proplot

f, ax = plot.subplots(width='12cm', proj='cyl')
ax.set_extent([-140, -107, 20, 50], crs=ccrs.PlateCarree())

Huge error chain ending in:

ValueError: Not enough room for axes (would have width -33.5696). Increase width, or reduce spacings 'left', 'right', or 'wspace'.

matplotlib

f, ax = plt.subplots(subplot_kw=dict(projection=ccrs.PlateCarree()))
ax.set_extent([-140, -107, 20, 50])
ax.coastlines()

[lukelbd]

P.S. In a recent commit (e78c43d), I fixed the issues with “smart tight layout” and zoomed-in cartopy projections. There is actually a cartopy github issue with the solution posted, it just hasn’t been implemented yet. ProPlot will now also fix issues associated with “zoomed in” cartopy projections having different aspect ratios than the intial aspect ratios, so you will no longer end up with a bunch of unnecessary empty space in your plot.

Anyway, now the only case when “smart tight layout” has to be disabled is when you use parallel/meridian labels with cartopy.

[bradyrx]

Thanks for all the tips, @lukelbd. I thought I had tried the proj_kw but maybe not. This is a pretty simple solution!

Good example you added to the docs. Maybe you should also add one to polar-specific projections. I’m just getting into Southern Ocean stuff so getting used to these keywords. Note that of course it doesn’t use rectangular coordinates. You just pass boundinglat to set the extent.

f, ax = plot.subplots(proj='spstere', basemap=True,
                      axwidth='10cm', 
                      proj_kw={'boundinglat': -30, 'lon_0': 120})
ax.pcolormesh(ds.XC, ds.YC, ds, vmin=-10, vmax=10,
              cmap='RdBu')
ax.format(land=True)