An edge list is a two-column matrix or data.frame where the first column contains the source vertices and the second column contains the target vertices.
Usage
graph_from_data_frame(edgelist, directed = TRUE)
graph_from_symbolic_edgelist(edgelist, directed = TRUE)
graph_from_edgelist(edgelist, directed = TRUE)Arguments
- edgelist
An edge list in two-column matrix or data.frame format.
graph_from_edgelist()only accepts integer values, interpreting them directly as vertex IDs starting from 1. Other functions support non-numeric values, treating them as vertex names. A data.frame may contain additional columns for edge attributes.- directed
A logical.
Value
An igraph_ptr object.
See also
as.data.frame.igraph_ptr() and as.matrix.igraph_ptr()
do the opposite conversion.
Examples
edges = seq_len(6L) + 3L
edgelist = matrix(edges, ncol = 2L, byrow = TRUE)
g = graph_from_edgelist(edgelist) |> print()
#> $V tibble [9 × 0] (S3: tbl_df/tbl/data.frame)
#> Named list()
#> # A tibble: 3 × 2
#> from to
#> <int> <int>
#> 1 4 5
#> 2 6 7
#> 3 8 9
stopifnot(all.equal(as.matrix(g), as.matrix(graph_create(edges))))
symbolic = matrix(letters[edges], ncol = 2L)
graph_from_symbolic_edgelist(symbolic)
#> $V tibble [6 × 1] (S3: tbl_df/tbl/data.frame)
#> $ name: chr [1:6] "d" "g" "e" "h" ...
#> # A tibble: 3 × 2
#> from to
#> <chr> <chr>
#> 1 d g
#> 2 e h
#> 3 f i