# R igraph manual pages

Use this if you are using igraph from R

 articulation_points {igraph} R Documentation

## Articulation points and bridges of a graph

### Description

articulation_points finds the articulation points (or cut vertices)

### Usage

articulation_points(graph)

bridges(graph)


### Arguments

 graph The input graph. It is treated as an undirected graph, even if it is directed.

### Details

Articulation points or cut vertices are vertices whose removal increases the number of connected components in a graph. Similarly, bridges or cut-edges are edges whose removal increases the number of connected components in a graph. If the original graph was connected, then the removal of a single articulation point or a single bridge makes it undirected. If a graph contains no articulation points, then its vertex connectivity is at least two.

### Value

For articulation_points, a numeric vector giving the vertex IDs of the articulation points of the input graph. For bridges, a numeric vector giving the edge IDs of the bridges of the input graph.

### Author(s)

Gabor Csardi csardi.gabor@gmail.com

biconnected_components, components, is_connected, vertex_connectivity, edge_connectivity

### Examples


g <- disjoint_union( make_full_graph(5), make_full_graph(5) )
clu <- components(g)\$membership
g <- add_edges(g, c(match(1, clu), match(2, clu)) )
articulation_points(g)

g <- make_graph("krackhardt_kite")
bridges(g)



[Package igraph version 1.3.2 Index]