Simple features in R (3)

library(dplyr, warn.conflicts = FALSE)
glimpse(nc)
## Rows: 100
## Columns: 15
## $ AREA      <dbl> 0.114, 0.061, 0.143, 0.070, 0.153, 0.097, 0.062, 0.091, 0.11…
## $ PERIMETER <dbl> 1.442, 1.231, 1.630, 2.968, 2.206, 1.670, 1.547, 1.284, 1.42…
## $ CNTY_     <dbl> 1825, 1827, 1828, 1831, 1832, 1833, 1834, 1835, 1836, 1837, …
## $ CNTY_ID   <dbl> 1825, 1827, 1828, 1831, 1832, 1833, 1834, 1835, 1836, 1837, …
## $ NAME      <chr> "Ashe", "Alleghany", "Surry", "Currituck", "Northampton", "H…
## $ FIPS      <chr> "37009", "37005", "37171", "37053", "37131", "37091", "37029…
## $ FIPSNO    <dbl> 37009, 37005, 37171, 37053, 37131, 37091, 37029, 37073, 3718…
## $ CRESS_ID  <int> 5, 3, 86, 27, 66, 46, 15, 37, 93, 85, 17, 79, 39, 73, 91, 42…
## $ BIR74     <dbl> 1091, 487, 3188, 508, 1421, 1452, 286, 420, 968, 1612, 1035,…
## $ SID74     <dbl> 1, 0, 5, 1, 9, 7, 0, 0, 4, 1, 2, 16, 4, 4, 4, 18, 3, 4, 1, 1…
## $ NWBIR74   <dbl> 10, 10, 208, 123, 1066, 954, 115, 254, 748, 160, 550, 1243, …
## $ BIR79     <dbl> 1364, 542, 3616, 830, 1606, 1838, 350, 594, 1190, 2038, 1253…
## $ SID79     <dbl> 0, 3, 6, 2, 3, 5, 2, 2, 2, 5, 2, 5, 4, 4, 6, 17, 4, 7, 1, 0,…
## $ NWBIR79   <dbl> 19, 12, 260, 145, 1197, 1237, 139, 371, 844, 176, 597, 1369,…
## $ geometry  <MULTIPOLYGON [°]> MULTIPOLYGON (((-81.47276 3..., MULTIPOLYGON ((…