Skip to contents

graph_from_atlas() creates graphs from the book ‘An Atlas of Graphs’ by Roland C. Read and Robin J. Wilson. The atlas contains all undirected graphs with up to seven vertices, numbered from 0 up to 1252. The graphs are listed:

  1. in increasing order of number of nodes;

  2. for a fixed number of nodes, in increasing order of the number of edges;

  3. for fixed numbers of nodes and edges, in increasing order of the degree sequence, for example 111223 < 112222;

  4. for fixed degree sequence, in increasing number of automorphisms.

Usage

graph_from_atlas(n)

atlas(...)

Arguments

n

The id of the graph to create.

...

Passed to graph_from_atlas().

Value

An igraph graph.

Examples

## Some randomly picked graphs from the atlas
graph_from_atlas(sample(0:1252, 1))
#> IGRAPH 7dc1163 U--- 7 15 -- Graph from the Atlas #1197
#> + attr: name (g/c), n (g/n)
#> + edges from 7dc1163:
#>  [1] 1--2 1--3 1--4 1--5 1--6 1--7 2--6 2--7 3--5 3--6 3--7 4--5 4--6 4--7 5--7
graph_from_atlas(sample(0:1252, 1))
#> IGRAPH 9bb4a36 U--- 6 7 -- Graph from the Atlas #112
#> + attr: name (g/c), n (g/n)
#> + edges from 9bb4a36:
#> [1] 1--2 2--5 3--5 3--4 2--6 3--6 2--3