plot.R

library(sf)
nc = st_read(system.file("shape/nc.shp", package="sf"))
nc <- st_transform(nc, 32119)
# regular grid 512096 polygons
grid <- st_make_grid(x = nc, cellsize = 500)

t0 <- Sys.time()
plot(st_geometry(nc))
plot(grid, add = TRUE)
# end of the second plot
t1 <- Sys.time()
# actual display in RStudio Plots window
t2 <- Sys.time()
# t2 - t0
# ~ 58 secs

t3 <- Sys.time()
png("test.png")
plot(st_geometry(nc))
plot(grid, add = TRUE)
dev.off()
t4 <- Sys.time()
# t4 - t3
# ~ 23 secs