liblwgeom geodetic functions
liblwgeom geodetic functions for length, area, segmentizing, covers
st_geod_area(x) st_geod_length(x) st_geod_segmentize(x, max_seg_length) st_geod_covers(x, y, sparse = TRUE) st_geod_covered_by(x, y, sparse = TRUE) st_geod_distance(x, y, tolerance = 0, sparse = FALSE)
x |
object of class |
max_seg_length |
segment length in degree, radians, or as a length unit (e.g., m) |
y |
object of class |
sparse |
logical; if |
tolerance |
double or length |
st_area will give an error message when the area spans the equator and lwgeom is linked to a proj.4 version older than 4.9.0 (see lwgeom_extSoftVersion)
longitude coordinates returned are rescaled to [-180,180)
this function should is used by st_distance, do not use it directly
library(sf)
nc = st_read(system.file("gpkg/nc.gpkg", package="sf"))
st_geod_area(nc[1:3,])
# st_area(nc[1:3,])
l = st_sfc(st_linestring(rbind(c(7,52), c(8,53))), crs = 4326)
st_geod_length(l)
library(units)
pol = st_polygon(list(rbind(c(0,0), c(0,60), c(60,60), c(0,0))))
x = st_sfc(pol, crs = 4326)
seg = st_geod_segmentize(x[1], set_units(10, km))
plot(seg, graticule = TRUE, axes = TRUE)
pole = st_polygon(list(rbind(c(0,80), c(120,80), c(240,80), c(0,80))))
pt = st_point(c(0,90))
x = st_sfc(pole, pt, crs = 4326)
st_geod_covers(x[c(1,1,1)], x[c(2,2,2,2)])
pole = st_polygon(list(rbind(c(0,80), c(120,80), c(240,80), c(0,80))))
pt = st_point(c(30,70))
x = st_sfc(pole, pt, crs = 4326)
st_geod_distance(x, x)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.