# intersect.owin

0th

Percentile

##### Intersection or Union of Two Windows

Yields the intersection or union of two windows.

Keywords
spatial, math
##### Usage
intersect.owin(A, B, ...)
union.owin(A,B, ...)
##### Arguments
A
A window object (see Details).
B
A window object.
...
Optional arguments passed to as.mask to control the discretisation, if required.
##### Details

The function intersect.owin computes the intersection between the two windows A and B, while union.owin computes their union.

The arguments A and B must be window objects (either objects of class "owin", or data that can be coerced to this class by as.owin).

At present the intersection or union of two polygons is computed by discretising them, yielding a binary image mask. If the intersection or union is empty, an error occurs.

##### Value

• A window object.

is.subset.owin, overlap.owin, bounding.box, owin.object

##### Aliases
• intersect.owin
• union.owin
##### Examples
# rectangles
u <- unit.square()
v <- owin(c(0.5,3.5), c(0.4,2.5))
# polygon
data(letterR)

# two rectangles
intersect.owin(u, v)
union.owin(u,v)

# polygon and rectangle
intersect.owin(letterR, v)
union.owin(letterR,v)

intersect.owin(m, v)
union.owin(m,v)

p <- rotate(v, 0.2)
intersect.owin(m, p)
union.owin(m,p)
#
A <- letterR
B <- rotate(letterR, 0.2)
plot(bounding.box(A,B), main="intersection")
w <- intersect.owin(A, B)
plot(B, add=TRUE)