terra (version 1.8-86)

relate: Spatial relationships between geometries

Description

relate returns a logical matrix indicating the presence or absence of a specific spatial relationships between the geometries in x and y.

is.related returns a logical vector indicating the presence or absence of a specific spatial relationships between x and any of the geometries in y.

Usage

# S4 method for SpatVector,SpatVector
relate(x, y, relation, pairs=FALSE, na.rm=TRUE)
# S4 method for SpatVector,missing
relate(x, y, relation, pairs=FALSE, na.rm=TRUE)
# S4 method for SpatVector,SpatVector
is.related(x, y, relation)

Value

matrix (relate) or vector (is.related)

See Also

compareGeom to check if the geometries are identical (equivalent to the "equals" relation)

adjacent, nearby, intersect, crop

Examples

# polygons
p1 <- vect("POLYGON ((0 0, 8 0, 8 9, 0 9, 0 0))")
p2 <- vect("POLYGON ((5 6, 15 6, 15 15, 5 15, 5 6))")
p3 <- vect("POLYGON ((8 2, 9 2, 9 3, 8 3, 8 2))")
p4 <- vect("POLYGON ((2 6, 3 6, 3 8, 2 8, 2 6))")
p5 <- vect("POLYGON ((2 12, 3 12, 3 13, 2 13, 2 12))")
p6 <- vect("POLYGON ((10 4, 12 4, 12 7, 11 7, 11 6, 10 6, 10 4))")

p <- rbind(p1, p2, p3, p4, p5, p6)
plot(p, col=rainbow(6, alpha=.5))
lines(p, lwd=2)
text(p)

## relate SpatVectors
relate(p1, p2, "intersects")
relate(p1, p3, "touches")
relate(p1, p5, "disjoint")
relate(rbind(p1, p2), p4, "disjoint")

## relate geometries within SpatVectors
# which are completely separated?
relate(p, relation="disjoint")

# which touch (not overlap or within)?
relate(p, relation="touches")
# which overlap (not merely touch, and not within)?
relate(p, relation="overlaps")
# which are within (not merely overlap)?
relate(p, relation="within")

# do they touch or overlap or are within?
relate(p, relation="intersects")

all(relate(p, relation="intersects") == 
  (relate(p, relation="overlaps") | 
   relate(p, relation="touches") |
   relate(p, relation="within")))

#for polygons, "coveredby" is "within"
relate(p, relation="coveredby")

# polygons, lines, and points 

pp <- rbind(p1, p2)
L1 <- vect("LINESTRING(1 11, 4 6, 10 6)")
L2 <- vect("LINESTRING(8 14, 12 10)")
L3 <- vect("LINESTRING(1 8, 12 14)")
lns <- rbind(L1, L2, L3)
pts <- vect(cbind(c(7,10,10), c(3,5,6)))

plot(pp, col=rainbow(2, alpha=.5))
text(pp, paste0("POL", 1:2), halo=TRUE)
lines(pp, lwd=2)
lines(lns, col=rainbow(3), lwd=4)
text(lns, paste0("L", 1:3), halo=TRUE)
points(pts, cex=1.5)
text(pts, paste0("PT", 1:3), halo=TRUE, pos=4)


relate(lns, relation="crosses")
relate(lns, pp, relation="crosses") 
relate(lns, pp, relation="touches") 
relate(lns, pp, relation="intersects") 

relate(lns, pp, relation="within")
# polygons can contain lines or points, not the other way around
relate(lns, pp, relation="contains") 
relate(pp, lns, relation="contains") 
# points and lines can be covered by polygons
relate(lns, pp, relation="coveredby")

relate(pts, pp, "within")
relate(pts, pp, "touches")
relate(pts, lns, "touches")