spatstat (version 1.64-1)

pairdist.lpp: Pairwise shortest-path distances between points on a linear network

Description

Given a pattern of points on a linear network, compute the matrix of distances between all pairs of points, measuring distance by the shortest path in the network.

Usage

# S3 method for lpp
pairdist(X, ..., 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".

…

Ignored.

Value

A symmetric matrix, whose values are nonnegative numbers or infinity (Inf).

Algorithms and accuracy

Distances are accurate within the numerical tolerance of the network, summary(X)$toler.

For network data stored in the non-sparse representation described in linnet, then pairwise distances are computed using the matrix of path distances between vertices of the network, using R code if method = "interpreted", or using C code if method="C" (the default).

For networks stored in the sparse representation, the argument method has no effect, and the distances are computed using an efficient C algorithm.

Details

Given a pattern of points on a linear network, this function computes the matrix of distances between all pairs of points, measuring distance by the shortest path in the network.

If two points cannot be joined by a path, the distance between them is infinite (Inf).

The argument method is not normally used. It is retained only for developers to check the validity of the software.

See Also

lpp

Examples

# NOT RUN {
   X <- runiflpp(12, simplenet)
   d <- pairdist(X)
   d[1:3, 1:3]
# }