Calculates the area of intersection of rectangles, specified by position
vectors x and y.

Usage

rectint(x, y)

Arguments

x, y

both vectors of length 4, or both matrices with 4 columns.

Value

Returns a scalar if x and y are vectors. If x is
a n-by-4 and y a m-by-4 matrix, then it returns
a n-by-m matrix R with entry (i,j) being the area
rectint(x[i,], y[j,]).

Details

Rectangles are specified as position vectors, that is c(x[1],x[2])
is the lower left corner, x[3] and x[4] are width and height
of the rectangle. When x and y are matrices, each row is
assumed to be a position vector specifying a rectangle.