A 'SpatialPolygonsDataFrame' [package "sp"] object containing country boundaries derived from Natural Earth data. Polygons are attributed with country codes. Derived from version 1.4.0 of Natural Earth data 1:50 m data.
The format is: Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots
The different country boundaries in rworldmap are processed from Natural
Earth Data as follows :
All :
~ rename any non-ASCII country names
that cause R trouble
~ rename Curacao which is particularly troublesome
!
~ check polygon geometries using checkPolygonsHoles
~ set
projections, e.g. proj4string(countriesCoarse) <- CRS("+proj=longlat
+ellps=WGS84 +datum=WGS84 +no_defs")
~ set polygon IDs to country names
(from ADMIN field)
~ copy ISO_A3 to ISO3
~ replace missing ISO3
codes (6 in this version) with ADM0_A3
~ check for duplicate ISO3 codes
(2 in this version)
~ set ISO3 for Gaza to Gaza and 'Ashmore and Cartier
Islands' to Ashm
~ replace POP_EST of -99 with NA
~ join on
countryRegions data
countriesCoarseLessIslands : ne_110
countriesCoarse : ne_110 plus extra
countries from ne_50 plus Tuvalu from ne_10
countriesLow : ne_50 plus
Tuvalu from ne_10
countriesHigh (in package rworldxtra) : ne_10