terra (version 1.9-11)

combineGeoms: Combine geometries

Description

Combine the geometries of one SpatVector with those of another. Geometries can be combined based on overlap, shared boundaries and distance (in that order of operation).

The typical use-case of this method is when you are editing geometries and you have a number of small polygons in one SpatVector that should be part of the geometries of the other SpatVector; perhaps because they were small holes in between the borders of two SpatVectors.

To append SpatVectors use `rbind` and see methods like intersect and union for "normal" polygons combinations.

Usage

# S4 method for SpatVector,SpatVector
combineGeoms(x, y, overlap=TRUE, boundary=TRUE, distance=TRUE,
	append=TRUE, minover=0.1, maxdist=Inf, dissolve=TRUE, erase=TRUE)

Value

SpatVector

See Also

union, erase, intersect, sharedPaths, aggregate, rbind

Examples

x1 <- vect("POLYGON ((0 0, 8 0, 8 9, 0 9, 0 0))")
x2 <- vect("POLYGON ((10 4, 12 4, 12 7, 11 7, 11 6, 10 6, 10 4))")

y1 <- vect("POLYGON ((5 6, 15 6, 15 15, 5 15, 5 6))")
y2 <- vect("POLYGON ((8 2, 9 2, 9 3, 8 3, 8 2))")
y3 <- vect("POLYGON ((2 6, 3 6, 3 8, 2 8, 2 6))")
y4 <- vect("POLYGON ((2 12, 3 12, 3 13, 2 13, 2 12))")

x <- rbind(x1, x2)
values(x) <- data.frame(xid=1:2)
crs(x) <- "+proj=utm +zone=1"

y <- rbind(y1, y2, y3, y4)
values(y) <- data.frame(yid=letters[1:4])
crs(y) <- "+proj=utm +zone=1"

plot(rbind(x, y), border=c(rep("red",2), rep("blue", 4)), lwd=2)
text(x, "xid")
text(y, "yid")

v <- combineGeoms(x, y)
plot(v, col=c("red", "blue"))

v <- combineGeoms(x, y, boundary=FALSE, maxdist=1, minover=.05)
plot(v, col=rainbow(4))