Compute Minimum or Maximum Nearest-Neighbour Distance
A faster way to compute the minimum or maximum nearest-neighbour distance in a point pattern.
minnndist(X, positive=FALSE, by=NULL) maxnndist(X, positive=FALSE, by=NULL)
X |
A point pattern (object of class |
positive |
Logical. If |
by |
Optional. A factor, which separates |
These functions find the minimum and maximum values
of nearest-neighbour distances in the point pattern X.
minnndist(X) and maxnndist(X) are
equivalent to, but faster than, min(nndist(X))
and max(nndist(X)) respectively.
The value is NA if npoints(X) < 2.
A single numeric value (possibly NA).
If by is given, the result is a numeric matrix
giving the minimum or maximum nearest neighbour distance
between each subset of X.
Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.
min(nndist(swedishpines))
minnndist(swedishpines)
max(nndist(swedishpines))
maxnndist(swedishpines)
minnndist(lansing, positive=TRUE)
if(interactive()) {
X <- runifrect(1e6)
system.time(min(nndist(X)))
system.time(minnndist(X))
}
minnndist(amacrine, by=marks(amacrine))
maxnndist(amacrine, by=marks(amacrine))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.