simplify.owin {spatstat} | R Documentation |
Given a polygonal window, this function finds a simpler polygon that approximates it.
simplify.owin(W, dmin)
W |
The polygon which is to be simplied.
An object of class |
dmin |
Numeric value. The smallest permissible length of an edge. |
This function simplifies a polygon W
by recursively deleting the shortest edge of W
until all remaining edges are longer than the specified
minimum length dmin
, or until there are only three edges left.
The argument W
must be a window (object of class
"owin"
). It should be of type "polygonal"
.
If W
is a rectangle, it is returned without alteration.
The simplification algorithm is not yet implemented for
binary masks. If W
is a mask, an error is generated.
Another window (object of class "owin"
)
of type "polygonal"
.
Adrian Baddeley Adrian.Baddeley@csiro.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner r.turner@auckland.ac.nz
data(letterR) plot(letterR, col="red") plot(simplify.owin(letterR, 0.3), col="blue", add=TRUE) data(chorley) W <- chorley$window plot(W) WS <- simplify.owin(W, 2) plot(WS, add=TRUE, border="green") points(vertices(WS))