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 for MapPanel().

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.