9.4. Using Projections#
There are three pre-defined projections that can be used, ‘lcc’
, ‘mer’
, ‘ps’
, or 'area'
.
lcc
: Lambert Conic Conformal
central latitude of 40ºN; central longitude -100ºE; standard parallels of 30º and 60ºN
mer
: Mercator
ps
: Polar Stereographic
central longitude -100ºE
area
: Uses the projection associated with the named area string
To use this you must have a valid string in the
area
setting forMapPanel()
.
Additionally, the projection can also be set to any valid Cartopy Projection…
Cartopy Projections: https://scitools.org.uk/cartopy/docs/latest/reference/projections.html
To use a Cartopy Projection you need to add to your import list the following:
import cartopy.crs as ccrs
Then you can specify any projection (with arguments as needed). For example,
panel.projection = ccrs.PlateCarree()
or
panel.projection = ccrs.Miller()
This is especially useful if you are plotting a map panel over a given state or region that might be better to have a different rotation than what are in the preset projections.