R Classes and dhdjd Methods for Spatial Data.

Before sp is loaded, options("sp_evolution_status") may be set to 0L for legacy behaviour, 1L for setting CRS(, doCheckCRSArgs=FALSE, ) and other minor steps to block calls out to rgdal etc., and 2L to use sf internally (not completed yet). If this option is not set, the environment variable _SP_EVOLUTION_STATUS_ can be used, again before sp is loaded, set to "0", "1" or "2"; this is used for running revdep checks under different evolution scenarios, anticipating retirement of maptools, rgdal and rgeos.

See:

• Pebesma, E.J., R.S. Bivand, 2005. Classes and methods for spatial data in R. R News 5 (2).
• Roger S. Bivand, Edzer Pebesma, Virgilio Gómez-Rubio, 2013. Applied Spatial Data Analysis with R, Second edition. Springer, NY.
• an sp maps gallery.