The projInfo
function lists known values and descriptions for PROJ.4 tags for tag in c("proj", "ellps", "datum", "units")
; getPROJ4VersionInfo
returns the version of the underlying PROJ.4 release, getPROJ4libPath
returns the value of the PROJ_LIB environment variable, projNAD
detects the presence of NAD datum conversion tables (looking for conus).