nndist.lpp: Nearest neighbour distances on a linear network
Description
Given a pattern of points on a linear network, compute the
nearest-neighbour distances, measured
by the shortest path in the network.
Usage
## S3 method for class 'lpp':
nndist(X, ..., k=1, method="C")
Arguments
X
Point pattern on linear network (object of class "lpp").
method
Optional string determining the method of calculation.
Either "interpreted" or "C".
k
Integer, or integer vector. The algorithm will compute the distance to the
kth nearest neighbour.
...
Ignored.
Value
A numeric vector, of length equal to the number of points in X,
or a matrix, with one row for each point in X and one column
for each entry of k.
Details
Given a pattern of points on a linear network, this function computes the
nearest neighbour distance for each point (i.e. the distance
from each point to the nearest other point), measuring
distance by the shortest path in the network.
If method="C" the distances are computed using
code in the C language. If method="interpreted" then the
computation is performed using interpreted Rcode. The Rcode is
much slower, but is provided for checking purposes.