| tilePerim {deldir} | R Documentation |
Calculates the perimeters of all of the Dirichlet (Voronoi) tiles in a tessellation of a set of planar points. Also calculates the sum and the mean of these perimeters.
tilePerim(object,inclbdry=TRUE)
object |
An object of class |
inclbdry |
Logical scalar. Should boundary segments (edges of tiles
at least one of whose endpoints lies on the enclosing
rectangle |
A list with components
perimeters |
A vector consisting of the values of the perimeters of the Dirichlet tiles in the tessellation. |
totalPerim |
The sum of |
meanPerim |
The mean of |
Function added at the request of Haozhe Zhang.
Rolf Turner r.turner@auckland.ac.nz https://www.stat.auckland.ac.nz/~rolf
tile.list(), plot.tile.list()
x <- runif(20)
y <- runif(20)
z <- deldir(x,y,rw=c(0,1,0,1))
w <- tile.list(z)
p1 <- tilePerim(w)
p0 <- tilePerim(w,inclbdry=FALSE)
p1$totalPerim - p0$totalPerim # Get 4 = the perimeter of rw.
ss <- apply(as.matrix(z$dirsgs[,1:4]),1,
function(x){(x[1]-x[3])^2 + (x[2]-x[4])^2})
2*sum(sqrt(ss)) - p0$totalPerim # Get 0; in tilePerim() each interior
# edge is counted twice.