| area.owin {spatstat} | R Documentation |
Computes the area of a window
area.owin(w)
w |
A window, whose area will be computed.
This should be an object of class owin,
or can be given in any format acceptable to as.owin().
|
If the window W is of type "rectangle" or "polygonal",
the area of this rectangular window is computed by analytic geometry.
If W is of type "mask"
the area of the discrete raster approximation of the window is
computed by summing the binary image values and adjusting for
pixel size.
A numerical value giving the area of the window.
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner r.turner@auckland.ac.nz
perimeter,
diameter,
owin.object,
as.owin
w <- unit.square()
area.owin(w)
# returns 1.00000
k <- 6
theta <- 2 * pi * (0:(k-1))/k
co <- cos(theta)
si <- sin(theta)
mas <- owin(c(-1,1), c(-1,1), poly=list(x=co, y=si))
area.owin(mas)
# returns approx area of k-gon
mas <- as.mask(square(2), eps=0.01)
X <- raster.x(mas)
Y <- raster.y(mas)
mas$m <- ((X - 1)^2 + (Y - 1)^2 <= 1)
area.owin(mas)
# returns 3.14 approx