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)
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.
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