I’m new to this list (but not matplotlib and basemap), and am not sure if this is the place to post basemap questions. I apologise if I have erred.
I’m reporting an issue whereby if I try to plot a zoomed in orthographic projection with a bluemarble (or etopo or shaded relief) background, the background remains “global,” though it’s oriented to the correct location, not mapping to the zoomed projection coordinates. I am pasting in a simple demo code that illustrates the behaviour. If you use the lcc projection, all works fine, and if you use a “non-zoomed” ortho projection, the background maps correctly.
It seems that there is something preventing the background from mapping into anything but a “complete-domain” ortho projection. I’m not a great map person, and I realise I may be missing the boat on the way I’m trying to zoom my ortho projection, but I’m not sure.
Am I screwing up, or is it a bug?
import mpl_toolkits.basemap as bm
import matplotlib.pyplot as plt
import numpy as np
Define a lambert conformal over northwest United States
With this projection (centered on Montana, and zoomed in),
the background image does map to the zoomed in projection
theMap = bm.Basemap(projection=‘lcc’,
lat_0=47, lat_1=30, lat_2=60, lon_0=-115,
With this projection (centered on Vienna, and zoomed in),
the background image doesn’t map to the zoomed in projection
theMap = bm.Basemap(projection=‘ortho’,
Don Morton, Owner/Manager
Boreal Scientific Computing LLC
Fairbanks, Alaska USA