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:
in increasing order of number of nodes;
for a fixed number of nodes, in increasing order of the number of edges;
for fixed numbers of nodes and edges, in increasing order of the degree sequence, for example 111223 < 112222;
for fixed degree sequence, in increasing number of automorphisms.
See also
Other deterministic constructors:
graph_from_edgelist()
,
graph_from_literal()
,
make_chordal_ring()
,
make_empty_graph()
,
make_full_citation_graph()
,
make_full_graph()
,
make_graph()
,
make_lattice()
,
make_ring()
,
make_star()
,
make_tree()
Examples
## Some randomly picked graphs from the atlas
graph_from_atlas(sample(0:1252, 1))
#> IGRAPH 7c0690b U--- 7 7 -- Graph from the Atlas #303
#> + attr: name (g/c), n (g/n)
#> + edges from 7c0690b:
#> [1] 2--5 2--4 3--4 3--5 1--3 2--3 1--7
graph_from_atlas(sample(0:1252, 1))
#> IGRAPH 2c3bffe U--- 7 10 -- Graph from the Atlas #648
#> + attr: name (g/c), n (g/n)
#> + edges from 2c3bffe:
#> [1] 1--2 2--3 3--4 4--5 1--5 1--6 5--6 3--6 4--6 5--7