The SpatialNetwork class and constructor function

SpatialNetwork: a Class for Spatial Networks (lines and edges)

SpatialNetwork(sl, g, weight, weightfield, direction, zero)

Arguments

sl	object of one of (a sublasses of) SpatialLines, with links
g	object of class igraph; if missing, the graph is sorted out from the links
weight	weight for links (defaults to length of linestring)
weightfield	character; name of the attribute field of sl that will be used as weights
direction	numeric; if omitted, undirected graph, else integer vector indicating direction of a link: -1 for up-link, 0 for two-way, or 1 for down-link
zero	numeric; zero threshold passed on to zerodist

Value

object of class SpatialNetwork-class

Details

A class to store spatial networks, such as a road network.

Note

note

Slots

bbox

matrix, holding bounding box

proj4string

object of class CRS-class

lines

list

data

data.frame, holding attributes associated with lines

g

object of a subclass of igraph

weightfield

character; describing the weight field used

Examples

library(sp) # Lines, SpatialLines
l0 = cbind(c(1, 2), c(0, 0))
l1 = cbind(c(0, 0, 0), c(0, 1, 2))
l2 = cbind(c(0, 0, 0), c(2, 3, 4))
l3 = cbind(c(0, 1, 2), c(2, 2, 3))
l4 = cbind(c(0, 1, 2), c(4, 4, 3))
l5 = cbind(c(2, 2), c(0, 3))
l6 = cbind(c(2, 3), c(3, 4))
LL = function(l, ID) Lines(list(Line(l)), ID)
l = list(LL(l0, "e"), LL(l1, "a"), LL(l2, "b"), LL(l3, "c"), LL(l4, "d"), LL(l5, "f"), LL(l6, "g"))
sl = SpatialLines(l)
sln = SpatialNetwork(sl)
plot(sln)
points(sln)
library(igraph) # E
#> 
#> Attaching package: ‘igraph’
#> The following objects are masked from ‘package:stats’:
#> 
#>     decompose, spectrum
#> The following object is masked from ‘package:base’:
#> 
#>     union
text(V(sln@g)$x, V(sln@g)$y, E(sln@g), pos = 4)
plot(sln@g)