Tests connectivity between pairs of nodes

Tests connectivity between pairs of nodes. This function tests if two nodes are directly connected with an edge (i.e. if they are neighbours).

Usage

areNeighbours(V1, V2, graph)

Arguments

V1

A vector of node names.

V2

A vector of node names of the same length as V1.

graph

An object of class gGraph or graph::graphNEL (usually in the @graph slot of a gGraph object.

Value

a vector of logical, having one value for each pair of nodes.

See also

Other connectivity_functions: areConnected(), isConnected,gData-method, isReachable()

Examples

# create a small square graph
test_graph <- makeSquareGrid(25, lon.range = c(1, 5), lat.range = c(1, 5))
# get the coordinates of the first 10 nodes
getCoords(test_graph)[1:10, ]
#>    lon lat
#> 1    1   5
#> 2    1   4
#> 3    1   3
#> 4    1   2
#> 5    1   1
#> 6    2   5
#> 7    2   4
#> 8    2   3
#> 9    2   2
#> 10   2   1
# test that the function correctly identifies neighbours
# 1 and 2 are neighbours, but 1 and 9 are not
areNeighbours(V1 = c("1", "1"), V2 = c("2", "9"), graph = test_graph)
#>  1->2  1->9 
#>  TRUE FALSE