Re: [igraph] Creating all possible non-isomorphic graphs from N nodes

[Tamás Nepusz]

> 1. If I have N nodes, what is the shortest way to create all possible 
> non-isomorphic graphs? E.G for N=2 nodes, there are 2 possible graphs, N=3, 
> there are 4, N=4 there are 11, N=5 there are 34, etc
The shortest way is to download them from Brendan McKay's page ;) He has 
generated all the nonisomorphic connected graphs up to 10 vertices with his 
'nauty' software (more precisely its "geng" program):

http://cs.anu.edu.au/~bdm/data/graphs.html

By the way, the OEIS sequence A000088 gives you the number of all the connected 
nonisomoprhic graphs as a function of n:

http://oeis.org/A000088

According to this, it seems quite unpractical to generate all these graphs even 
for n=11.

> 2. Is it possible to have an array of graph objects of the form 
> G[1],G[2]...G[10]...?
Yes, it is. You did not mention which language you use igraph from so it's hard 
to be any more specific than this.

Cheers,
-- 
T.