# pairdist.lpp: Pairwise shortest-path distances between points on a linear... In spatstat.linnet: Linear Networks Functionality of the 'spatstat' Family

 pairdist.lpp 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.

`lpp`
```   X <- runiflpp(12, simplenet)