# R igraph manual pages

Use this if you are using igraph from R

## 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

components