5.6 Shift
The sf package implements affine transformation for objects of classes sfg
and sfc
.
= st_geometry(nz) #extracts geom column nz_sfc
= nz_sfc + c(1e5, 1e5) #shift by x = 10, y = 10 kilometers
nz_shift_sfc = st_set_geometry(nz, nz_shift_sfc) #return to sf type
nz_shift_sf st_crs(nz_shift_sf) <- st_crs(nz) #ensure same coordinate system
|>
nz ggplot() +
geom_sf() +
geom_sf(fill = "blue", alpha = 0.5,
data = nz_shift_sf) +
labs(title = "New Zealand",
subtitle = "Affine Transformation: Shift",
caption = "GeoComputation with R book club") +
theme_minimal()
![](images/shift.gif)
Shift