Computes the distance from each pixel to the nearest point in the given point pattern on a linear network.
# S3 method for lpp
distmap(X, ..., k=1)A pixel image on the network (object of class "linim")
whose greyscale values are the values of the distance map.
A point pattern on a linear network (object of class "lpp").
Integer. The distance to the k-th nearest data point
will be computed.
Arguments passed to as.linim.linfun
to control pixel resolution.
The pixel values in the image distmap(X) are distances,
expressed as multiples of the unit of length of the spatial
coordinates in X.
The unit of length is given by unitname(X).
Note that, if the unit of length in X is a composite
expression such as ‘2 microns’,
then the values in distmap(X) are expressed as multiples
of 2 microns, rather than being expressed in microns.
Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner rolfturner@posteo.net and Ege Rubak rubak@math.aau.dk.
This is a method for the generic function distmap.
It computes the distance map of the point pattern X
as a pixel image on the network.
At a pixel \(u\), the greyscale value
equals the distance from \(u\) to the
nearest point of the pattern X (or the \(k\)-th nearest point
of X).
Generic function distmap and methods.