# st_nearest_feature: get index of nearest feature In sf: Simple Features for R

## Description

get index of nearest feature

## Usage

 ```1 2 3 4 5 6 7``` ```st_nearest_feature( x, y, ..., check_crs = TRUE, longlat = isTRUE(st_is_longlat(x)) ) ```

## Arguments

 `x` object of class `sfg`, `sfc` or `sf` `y` object of class `sfg`, `sfc` or `sf`; if missing, features in codex will be compared to all remaining features in `x`. `...` ignored `check_crs` logical; should `x` and `y` be checked for CRS equality? `longlat` logical; does `x` have ellipsoidal coordinates?

## Value

for each feature (geometry) in `x` the index of the nearest feature (geometry) in set `y`, or in the remaining set of `x` if `y` is missing; empty geometries result in `NA` indexes

## See Also

st_nearest_points for finding the nearest points for pairs of feature geometries

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30``` ```ls1 = st_linestring(rbind(c(0,0), c(1,0))) ls2 = st_linestring(rbind(c(0,0.1), c(1,0.1))) ls3 = st_linestring(rbind(c(0,1), c(1,1))) (l = st_sfc(ls1, ls2, ls3)) p1 = st_point(c(0.1, -0.1)) p2 = st_point(c(0.1, 0.11)) p3 = st_point(c(0.1, 0.09)) p4 = st_point(c(0.1, 0.9)) (p = st_sfc(p1, p2, p3, p4)) try(st_nearest_feature(p, l)) try(st_nearest_points(p, l[st_nearest_feature(p,l)], pairwise = TRUE)) r = sqrt(2)/10 b1 = st_buffer(st_point(c(.1,.1)), r) b2 = st_buffer(st_point(c(.9,.9)), r) b3 = st_buffer(st_point(c(.9,.1)), r) circles = st_sfc(b1, b2, b3) plot(circles, col = NA, border = 2:4) pts = st_sfc(st_point(c(.3,.1)), st_point(c(.6,.2)), st_point(c(.6,.6)), st_point(c(.4,.8))) plot(pts, add = TRUE, col = 1) # draw points to nearest circle: nearest = try(st_nearest_feature(pts, circles)) if (inherits(nearest, "try-error")) # GEOS 3.6.1 not available nearest = c(1, 3, 2, 2) ls = st_nearest_points(pts, circles[nearest], pairwise = TRUE) plot(ls, col = 5:8, add = TRUE) # compute distance between pairs of nearest features: st_distance(pts, circles[nearest], by_element = TRUE) ```

sf documentation built on June 10, 2021, 1:06 a.m.