sp

R Classes and Methods for Spatial Data. Note that this is package will (slowly) be deprecated, in favor of package sf. It is in maintenance mode, and currently requires sf for coordinate reference system validation and coordinate transformation, conversion and (re)projection.

From version 2.1-0, sp has dropped maptools, rgdal and rgeos as suggested packages.

From version 2.0-0, sp evolution status is changed to 2L to use sf internally in place of rgdal, from default 0L until now. See this report for adaptation details, and this report for progress on retiring maptools, rgdal and rgeos.

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. 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.

From sp 1.6.0 published on CRAN 2023-01-19, these status settings may also be changed when sp is loaded, using sp::get_evolution_status() returning the current value, and sp::set_evolution_status(value), where value can take the integer values 0L, 1L and 2L. sp 1.6.1 published on CRAN 2023-05-25 added start-up messages to alert users to imminent changes.

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.