R: Examples for 'terra::distance'

### ** Examples

#lonlat
r <- rast(ncols=36, nrows=18, crs="+proj=longlat +datum=WGS84")
r[500] <- 1
d <- distance(r)
plot(d / 100000)

#planar
rr <- rast(ncols=36, nrows=18, crs="+proj=utm +zone=1 +datum=WGS84")
rr[500] <- 1
d <- distance(rr)

p1 <- vect(rbind(c(0,0), c(90,30), c(-90,-30)), crs="+proj=longlat +datum=WGS84")
dp <- distance(r, p1)

d <- distance(p1)
d

         1        2
2 10014577         
3 10014577 20003931

as.matrix(d)

         1        2        3
1        0 10014577 10014577
2 10014577        0 20003931
3 10014577 20003931        0

p2 <- vect(rbind(c(30,-30), c(25,40), c(-9,-3)), crs="+proj=longlat +datum=WGS84")
dd <- distance(p1, p2)
dd

         [,1]     [,2]     [,3]
[1,]  4596223  5104507  1054933
[2,]  9192445  5905838 11048088
[3,] 10825924 14117180  8981037

pd <- distance(p1, p2, pairwise=TRUE)
pd

[1] 4596223 5905838 8981037

pd == diag(dd)

[1] TRUE TRUE TRUE

# polygons, lines
crs <- "+proj=utm +zone=1"
p1 <- vect("POLYGON ((0 0, 8 0, 8 9, 0 9, 0 0))", crs=crs)
p2 <- vect("POLYGON ((5 6, 15 6, 15 15, 5 15, 5 6))", crs=crs)
p3 <- vect("POLYGON ((2 12, 3 12, 3 13, 2 13, 2 12))", crs=crs)
p <- rbind(p1, p2, p3)
L1 <- vect("LINESTRING(1 11, 4 6, 10 6)", crs=crs)
L2 <- vect("LINESTRING(8 14, 12 10)", crs=crs)
L3 <- vect("LINESTRING(1 8, 12 14)", crs=crs)
lns <- rbind(L1, L2, L3)
pts <- vect(cbind(c(7,10,10), c(3,5,6)), crs=crs)

distance(p1,p3)

     [,1]
[1,]    3

distance(p)

  1 2
2 0  
3 3 2

distance(p,pts)

         [,1]     [,2]     [,3]
[1,] 0.000000 2.000000 2.000000
[2,] 3.000000 1.000000 0.000000
[3,] 9.848858 9.899495 9.219544

distance(p,lns)

         [,1]     [,2]     [,3]
[1,] 0.000000 3.535534 0.000000
[2,] 0.000000 0.000000 0.000000
[3,] 1.414214 5.099020 2.553878

distance(pts,lns)

     [,1]     [,2]     [,3]
[1,]    3 8.602325 7.262591
[2,]    1 5.385165 6.943356
[3,]    0 4.472136 6.065460

Examples for 'terra::distance'

Geographic distance