combineGeoms function

Combine geometries

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 another SpatVector; perhaps because they were small holes inbetween the borders of two SpatVectors.

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

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

Arguments

• x: SpatVector of polygons
• y: SpatVector of polygons geometries that are to be combined with x
• overlap: logical. If TRUE, a geometry is combined with the geometry it has most overlap with, if the overlap is above minover
• boundary: logical. If TRUE, a geometry is combined with the geometry it has most shared border with
• distance: logical. If TRUE, a geometry is combined with the geometry it is nearest to
• append: logical. Should remaining geometries be appended to the output? Not relevant if distance=TRUE
• minover: numeric. The fraction of the geometry in y that overlaps with a geometry in x. Below this threshold, geometries are not considered overlapping
• maxdist: numeric. Geometries further away from each other than this distance (in meters) will not be combined
• dissolve: logical. Should internal boundaries be dissolved?
• erase: logical. If TRUE no new overlapping areas are created

Returns

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))