R version 4.2.0 (2022-04-22) -- "Vigorous Calisthenics"
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> library(sf)
Linking to GEOS 3.10.2, GDAL 3.4.3, PROJ 8.2.0; sf_use_s2() is TRUE
> d = data.frame(z = 1:100, x = runif(100), y = runif(100))
> n0 = st_as_sf(d, coords = c("x", "y"), crs = 4326)
> n1 = st_transform(n0, 3857)
>
> # st_nearest_points
> cp1 = st_nearest_points(n0[1:50,], n0[51:100,])
> cp2 = st_transform(st_nearest_points(n1[1:50,], n1[51:100,]), 4326)
> length(cp1)
[1] 2500
> all.equal(cp1, cp2)
[1] TRUE
>
> # st_nearest_points, pairwise
> cp1 = st_nearest_points(n0[1:50,], n0[51:100,], pairwise = TRUE)
> cp2 = st_transform(st_nearest_points(n1[1:50,], n1[51:100,], pairwise = TRUE), 4326)
> length(cp1)
[1] 50
> all.equal(cp1, cp2)
[1] TRUE
>
> if (compareVersion(sf_extSoftVersion()["GEOS"], "3.6.1") > -1) {
+ # st_nearest_feature
+ nf1 = st_nearest_feature(n0[1:50,], n0[51:100,])
+ nf2 = st_nearest_feature(n1[1:50,], n1[51:100,])
+ print(all.equal(nf1, nf2))
+ }
[1] TRUE
>
> set.seed(131)
> n = 1000
> pts = st_as_sf(data.frame(x = runif(n), y = runif(n)), coords = c("x", "y"), crs = 4326)
> # unit square in degrees: 111 x 111 km
>
> size = 15000
> w <- st_is_within_distance(pts[1,], pts, size)[[1]]
>
> bs = units::set_units(size / s2::s2_earth_radius_meters(), rad)
> b1 = st_buffer(pts[1,], bs)
> b2 = st_buffer(pts[1,], size)
> all.equal(b1, b2)
[1] TRUE
>
> #plot(pts)
> #plot(pts[1,], add = TRUE, pch = 16, cex = 2, col = 'blue')
> #plot(st_buffer(pts[1,], bs), add = TRUE)
> #plot(pts[w,], add = TRUE, col = 'red')
>
> proc.time()
user system elapsed
1.829 0.063 1.885
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