connectivity: Check connectivity of a gGraph object

In thibautjombart/geograph: Walking through the geographic space using graphs

Check connectivity of a gGraph object

Description

The functions areNeighbours, areConnected and the method isConnected test connectivity in different ways.

Usage

areNeighbours(V1, V2, graph)

areConnected(x, nodes)

## S4 method for signature 'gData'
isConnected(object, ...)

isReachable(x, loc)

connectivityPlot(x, ...)

## S4 method for signature 'gGraph'
connectivityPlot(x, ..., seed = NULL)

## S4 method for signature 'gData'
connectivityPlot(x, col.gGraph = 0, ..., seed = NULL)

Arguments

V1	a vector of node names
V2	a vector of node names
graph	a valid graphNEL object.
x	a valid gGraph object.
nodes	a vector of node names
object	a valid gData object.
...	other arguments passed to other methods.
loc	location, specified as a list of two components giving respectively the longitude and the latitude. Alternatively, it can be a matrix-like object with one row and two columns.
seed	an optional integer giving the seed to be used when randomizing colors. One given seed will always give the same set of colors. NULL by default, meaning colors are randomized each time a plot is drawn.
col.gGraph	a character string or a number indicating the color of the nodes to be used when plotting the gGraph object. Defaults to '0', meaning that nodes are invisible.

Details

• areNeighbours: tests connectivity between couples of nodes on an object inheriting graph class (like a graphNEL object).
  

• areConnected: tests if a set of nodes form a connected set on a gGraph object.
  

• isConnected: tests if the nodes of a gData object form a connected set. Note that this is a method for gData, the generic being defined in the graph package.
  

• isReachable: tests if one location (actually, the closest node to it) is reachable from the set of nodes of a gData object.
  

• connectivityPlot: plots connected sets of a gGraph or a gData object with different colors.
  

In connectivityPlot, isolated nodes (i.e. belonging to no connected set of size > 1) are plotted in light grey.

Value

• areNeighbours: a vector of logical, having one value for each couple of nodes.
  

• areConnected: a single logical value, being TRUE if nodes form a connected set.
  

• isConnected: a single logical value, being TRUE if nodes of the object form a connected set.
  

Examples

connectivityPlot(rawgraph.10k)
connectivityPlot(worldgraph.10k)

thibautjombart/geograph documentation built on April 13, 2025, 9:39 a.m.