get nearest points between pairs of geometries

```
st_nearest_points(x, y, ...)
# S3 method for sfc
st_nearest_points(x, y, ..., pairwise = FALSE)
# S3 method for sfg
st_nearest_points(x, y, ...)
# S3 method for sf
st_nearest_points(x, y, ...)
```

- x
object of class

`sfg`

,`sfc`

or`sf`

- y
object of class

`sfg`

,`sfc`

or`sf`

- ...
ignored

- pairwise
logical; if

`FALSE`

(default) return nearest points between all pairs, if`TRUE`

, return nearest points between subsequent pairs.

an sfc object with all two-point `LINESTRING`

geometries of point pairs from the first to the second geometry, of length x * y, with y cycling fastest. See examples for ideas how to convert these to `POINT`

geometries.

in case `x`

lies inside `y`

, when using S2, the end points
are on polygon boundaries, when using GEOS the end point are identical to `x`

.

st_nearest_feature for finding the nearest feature

```
r = sqrt(2)/10
pt1 = st_point(c(.1,.1))
pt2 = st_point(c(.9,.9))
pt3 = st_point(c(.9,.1))
b1 = st_buffer(pt1, r)
b2 = st_buffer(pt2, r)
b3 = st_buffer(pt3, r)
(ls0 = st_nearest_points(b1, b2)) # sfg
#> Geometry set for 1 feature
#> Geometry type: LINESTRING
#> Dimension: XY
#> Bounding box: xmin: 0.2 ymin: 0.2 xmax: 0.8 ymax: 0.8
#> CRS: NA
#> LINESTRING (0.2 0.2, 0.8 0.8)
(ls = st_nearest_points(st_sfc(b1), st_sfc(b2, b3))) # sfc
#> Geometry set for 2 features
#> Geometry type: LINESTRING
#> Dimension: XY
#> Bounding box: xmin: 0.2 ymin: 0.1 xmax: 0.8 ymax: 0.8
#> CRS: NA
#> LINESTRING (0.2 0.2, 0.8 0.8)
#> LINESTRING (0.2414214 0.1, 0.7585786 0.1)
plot(b1, xlim = c(-.2,1.2), ylim = c(-.2,1.2), col = NA, border = 'green')
plot(st_sfc(b2, b3), add = TRUE, col = NA, border = 'blue')
plot(ls, add = TRUE, col = 'red')
nc = read_sf(system.file("gpkg/nc.gpkg", package="sf"))
plot(st_geometry(nc))
ls = st_nearest_points(nc[1,], nc)
plot(ls, col = 'red', add = TRUE)
pts = st_cast(ls, "POINT") # gives all start & end points
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
#> Warning: point from first coordinate only
# starting, "from" points, corresponding to x:
plot(pts[seq(1, 200, 2)], add = TRUE, col = 'blue')
# ending, "to" points, corresponding to y:
plot(pts[seq(2, 200, 2)], add = TRUE, col = 'green')
```