Re: [Matplotlib-users] Background basemaps in Basemap

[klo uo <kl...@gm...>]

On Sun, Aug 26, 2012 at 12:18 AM, Jeff Whitaker <js...@fa...> wrote:
> Klo:  The image in interpolated to the Basemap projection region. This is
> slow - the main reason to use the WMS is to avoid this by having it done on
> the server side.

All right, that's the right way anyway


> The trick is to figure out what the EPSG projection code is based on the
> Basemap projection info, and pass that information to the WMS server so it
> can do the interpolation.

Yes, and also to pass right `size` parameter as aspect ratio needs to be correct
Do you want me to try to pair both projections (Basemap name and WKID
and WKT as they call it)?


> Here's an example for south polar stereographic:
>
> width = 12000.e3
> plt.figure()
> basemap_url =\
> "http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer/export?\
> bbox=%d,%d,%d,%d&\
> bboxSR=3412&\
> imageSR=3412&\
> size=800,800&\
> dpi=128&\
> format=png32&\
> f=image" % (-width/2,-width/2,width/2,width/2)
> m =\
> Basemap(projection='stere',resolution='i',lon_0=0,lat_0=-90,lat_ts=-70,\
>         width=width,height=width,rsphere=(6378273,6356889.449))
> m.imshow(plt.imread(urllib2.urlopen(basemap_url)),origin='upper')
> m.drawmeridians(np.arange(-180,180,30),labels=[0,0,0,1],color='y')
> m.drawparallels(np.arange(-80,-0,10),labels=[1,0,0,0],color='y')
> m.drawcoastlines()
> plt.show()
>

Looks beautifully :)

As said later today I'll look at Nokia maps and then will try to look
for WMS servers.