update data to Natural Earth v5.1.2.
add github action to automate data updates
This is a breaking changes release that ends support to sp object in favour of more modern interfaces (sf and terra). Although that sp is still available on CRAN, it is no longer being actively developed (https://geocompx.org/post/2023/rgdal-retirement/). This is the main reason that motivated the choice to transition toward sf (the default) and terra.
Users can choose either get an sf or SpatVector using the returnclass argument:
ne_countries(returnclass = "sf")
ne_countries(returnclass = "sv")
All spatial objects in the package (countries10, map_units10, sovereignty10, states10, coastline10) are now objects of class sf.
If changing the return type to sf creates too many problems to your existing code, you can still convert it back to sp :
# option 1
sf::as_Spatial(ojbcountries)
# option 2
as(countries, "Spatial")
More information about the retirement of rgdal, rgeos and maptools: https://r-spatial.org/r/2022/04/12/evolution.html