R: In- or out- component of a vertex

subcomponent {igraph} | R Documentation

## In- or out- component of a vertex

### Description

Finds all vertices reachable from a given vertex, or the opposite: all vertices from which a given vertex is reachable via a directed path.

### Usage

    subcomponent(graph, v, mode = c("all", "out", "in"))

### Arguments

`graph` | The graph to analyze.
`v` | The vertex to start the search from.
`mode` | Character string, either “in”, “out” or “all”. If “in” all vertices from which `v` is reachable are listed. If “out” all vertices reachable from `v` are returned. If “all” returns the union of these. It is ignored for undirected graphs.

### Details

A breadh-first search is conducted starting from vertex `v`.

### Value

Numeric vector, the ids of the vertices in the same component as `v`.

### Author(s)

Gabor Csardi csardi.gabor@gmail.com

### See Also

`components`

### Examples

    g <- sample_gnp(100, 1/200)
    subcomponent(g, 1, "in")
    subcomponent(g, 1, "out")
    subcomponent(g, 1, "all")

[Package igraph version 1.2.10 Index]