R: Pairwise shortest-path distances between points on a linear...

pairdist.lpp {spatstat.linnet} | R Documentation

## 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 class '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.

### 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.

### 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.

### Author(s)

Ang Qi Wei aqw07398@hotmail.com and Adrian Baddeley Adrian.Baddeley@curtin.edu.au.

### See Also

`lpp`

### Examples

       X <- runiflpp(12, simplenet)
       d <- pairdist(X)
       d[1:3, 1:3]

[Package spatstat.linnet version 2.0-0 Index]