geos_binary_ops {sftime}

Geometric operations on pairs of simple feature geometry sets (including sftime objects)

Description

Geometric operations on pairs of simple feature geometry sets (including sftime objects)

Intersection

Difference

Usage

## S3 method for class 'sftime'
st_intersection(x, y, ...)

## S3 method for class 'sftime'
st_difference(x, y, ...)

## S3 method for class 'sftime'
st_sym_difference(x, y, ...)

Arguments

x

object of class sftime, sf, sfc or sfg.

y

object of class sftime, sf, sfc or sfg.

...

See geos_binary_ops.

Details

st_intersection: When called with a missing y, the sftime method for st_intersection returns an sftime object with attributes taken from the contributing feature with lowest index; two fields are added:

n.overlaps

The number of overlapping features in x.

origins

A list-column with indexes of all overlapping features.

st_difference: When st_difference is called with a single argument, overlapping areas are erased from geometries that are indexed at greater numbers in the argument to x; geometries that are empty or contained fully inside geometries with higher priority are removed entirely.

Value

The intersection, difference or symmetric difference between two sets of geometries. The returned object has the same class as that of the first argument (x) with the non-empty geometries resulting from applying the operation to all geometry pairs in x and y. In case x is of class sf or sftime, the matching attributes of the original object(s) are added. The sfc geometry list-column returned carries an attribute idx, which is an n-by-2 matrix with every row the index of the corresponding entries of x and y, respectively.

Examples

g <- st_sfc(st_point(c(1, 2)), st_point(c(1, 3)), st_point(c(2, 3)), 
     st_point(c(2, 1)), st_point(c(3, 1)))
tc <- Sys.time() + 1:5
x1 <- st_sftime(a = 1:5, g, time = tc)
x2 <- st_buffer(x1, dist = 1)

## intersection

# only x provided (no y)
plot(st_intersection(x2))

# with arguments x and y provided
plot(st_intersection(x2, x1))

## difference

# only x provided (no y)
plot(st_difference(x2))

# with arguments x and y provided
plot(st_difference(x2, x1))

## symmetric difference
plot(st_sym_difference(x1, x2))