I'm using coordinate_cleaner's country test cc_coun but it's flagging entries with coordinates near to the edges country borders. To try to keep them I wanted to buffer the terrestrial area of countries, essentially expanding their borders a little so that it doesn't flag these entries.
I've tried:
require(rnaturalearth)
world <- ne_countries(scale = "large", returnclass = "sf") %>% st_buffer(dist=.001)
Using st_buffer(dist=.001) does change the geometry, but I noticed whatever I put into dist doesn't matter as it changes it to the same thing regardless (I tried .001, 0.1, 1, 2, and -1, though any minus number removes the geometry altogether).
I found that maybe I need to transform my sf file into something else and then use st_buffer so it's in meters rather than degrees(?). I saw this question/answer but I don't understand it well enough to help my situation: What unit is the `dist` argument in `st_buffer` set to by default?
In the end I'm looking to create a SpatialPolygonsDataFrame reference file to feed into cc_coun. Using the above code I followed on with:
world <- sf:::as_Spatial(world)
coun_test <- cc_coun(x = data,
lon = "Decimal_Long",
lat = "Decimal_Lat",
iso3 = "Country_code",
value = "flagged",
ref = world,
verbose = TRUE)
Which ended up flagging more entries than when I didn't use st_buffer on the reference fine.
In summary, I want to add a buffer to the edge of every country border by around 100 meters in a file I can use as a reference in this test. Is this the best way to go about it or is there a better/easier way? I'd appreciate any advice.
Thank you