Convert a graph to an edge list

Sometimes it is useful to work with a standard representation of a graph, like an edge list.

as_edgelist(graph, names = TRUE)

Arguments

graph

The graph to convert.

names

Whether to return a character matrix containing vertex names (i.e. the name vertex attribute) if they exist or numeric vertex ids.

Value

A ecount(graph) by 2 numeric matrix.

Details

as_edgelist() returns the list of edges in a graph.

See also

graph_from_adjacency_matrix(), read_graph()

Other conversion: as.matrix.igraph(), as_adj_list(), as_adjacency_matrix(), as_biadjacency_matrix(), as_data_frame(), as_directed(), as_graphnel(), as_long_data_frame(), graph_from_adj_list(), graph_from_graphnel()

Examples

g <- sample_gnp(10, 2 / 10)
as_edgelist(g)
#>       [,1] [,2]
#>  [1,]    1    2
#>  [2,]    1    5
#>  [3,]    3    6
#>  [4,]    5    6
#>  [5,]    4    7
#>  [6,]    5    8
#>  [7,]    7    8
#>  [8,]    2   10
#>  [9,]    3   10

V(g)$name <- LETTERS[seq_len(gorder(g))]
as_edgelist(g)
#>       [,1] [,2]
#>  [1,] "A"  "B" 
#>  [2,] "A"  "E" 
#>  [3,] "C"  "F" 
#>  [4,] "E"  "F" 
#>  [5,] "D"  "G" 
#>  [6,] "E"  "H" 
#>  [7,] "G"  "H" 
#>  [8,] "B"  "J" 
#>  [9,] "C"  "J"