The PostScript code is written to standard output. No space between the option flag and the associated arguments. Use upper case for the option flags and lower case for modifiers. Selects the map projection. More details can be found in the psbasemap manpages.
Sets map boundary tickmark intervals.
See psbasemap for details. Repeat option -I as often as necessary. Use - Lx to specify position in inch instead. Draw political boundaries. Repeat option -N as often as necessary.