R: Articulation points and bridges of a graph

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

### See Also

`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]