Miscellaneous operators

induced_subgraph() can be achieved in two steps with induced_subgraph_edges() and subgraph_from_edges(), but it is much slower than expected.

Usage

induced_subgraph(graph, vids, impl = 0L)

induced_subgraph_edges(graph, vids)

subgraph_from_edges(graph, eids, delete_vertices = TRUE)

Source

https://igraph.org/c/doc/igraph-Operators.html#miscellaneous-operators

Arguments

graph

An igraph_ptr object.

vids

An integer vector of vertex IDs.

impl

An integer value, how to construct a new graph: {0: AUTO, 1: COPY_AND_DELETE, 2: CREATE_FROM_SCRATCH}

eids

An integer vector of edge IDs.

delete_vertices

whether to delete the unused vertices.

Value

An igraph_ptr object.

See also

delete_vertices()

Examples

g = graph_tree(5L)
induced_subgraph(g, seq_len(3L))
#> $V  tibble [3 × 0] (S3: tbl_df/tbl/data.frame)
#>  Named list()
#> # A tibble: 2 × 2
#>    from    to
#>   <int> <int>
#> 1     1     2
#> 2     1     3

edges = induced_subgraph_edges(g, seq_len(3L)) |> print()
#> [1] 1 2

subgraph_from_edges(g, edges)
#> $V  tibble [3 × 0] (S3: tbl_df/tbl/data.frame)
#>  Named list()
#> # A tibble: 2 × 2
#>    from    to
#>   <int> <int>
#> 1     1     2
#> 2     1     3