r <- rast(ncols=2, nrows=2)
values(r) <- 1:ncell(r)
as.lines(r)
as.lines(ext(r), crs=crs(r))
if (gdal() >= "3.0.0") {
p <- as.polygons(r)
as.lines(p)
}
## with a matrix
s <- cbind(1:5, 1:5)
e <- cbind(1:5, 0)
as.lines(s)
as.lines(cbind(s, e), "+proj=longlat")
Run the code above in your browser using DataLab