Take Complement of a Window
Take the set complement of a window, within its enclosing rectangle or in a larger rectangle.
complement.owin(w, frame=as.rectangle(w))
w |
an object of class |
frame |
Optional. The enclosing rectangle, with respect to which the set complement is taken. |
This yields a window object (of class "owin",
see owin.object) representing the set complement
of w with respect to the rectangle frame.
By default, frame is the enclosing box of w
(originally specified by the arguments xrange and yrange
given to owin when w was created).
If frame is specified, it must be a rectangle (an object of
class "owin" whose type is "rectangle") and it must be
larger than the enclosing box of w. This rectangle becomes the
enclosing box for the resulting window.
If w is a rectangle, then frame must be specified.
Otherwise an error will occur (since the complement of w in
itself is empty).
For rectangular and polygonal windows, the complement is computed by reversing the sign of each boundary polygon, while for binary masks it is computed by negating the pixel values.
Another object of class "owin"
representing the complement of the window, i.e. the inside
of the window becomes the outside.
Adrian Baddeley Adrian.Baddeley@curtin.edu.au
and Rolf Turner r.turner@auckland.ac.nz
# rectangular a <- owin(c(0,1),c(0,1)) b <- owin(c(-1,2),c(-1,2)) bmina <- complement.owin(a, frame=b) # polygonal data(demopat) w <- Window(demopat) outside <- complement.owin(w) # mask w <- as.mask(Window(demopat)) outside <- complement.owin(w)
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.