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_(),
make_chordal_ring(),
make_circulant(),
make_empty_graph(),
make_full_citation_graph(),
make_full_graph(),
make_full_multipartite(),
make_graph(),
make_lattice(),
make_ring(),
make_star(),
make_tree(),
make_turan(),
make_wheel()
Examples
## Some randomly picked graphs from the atlas
graph_from_atlas(sample(0:1252, 1))
#> IGRAPH 4c6a54d U--- 7 9 -- Graph from the Atlas #464
#> + attr: name (g/c), n (g/n)
#> + edges from 4c6a54d:
#> [1] 2--4 2--3 1--3 1--6 5--6 4--5 3--4 1--4 1--5
graph_from_atlas(sample(0:1252, 1))
#> IGRAPH b4ec356 U--- 6 8 -- Graph from the Atlas #139
#> + attr: name (g/c), n (g/n)
#> + edges from b4ec356:
#> [1] 1--2 2--3 3--4 4--5 1--5 2--4 2--5 1--6