# How to use Automorphisms[] on a graph? [duplicate]

I am having difficulty mixing the new post-Combinatorica graph data structure, with functionality apparently only in Combinatorica.

I have constructed a graph using Graph[], e.g.,

n = 4; g = Graph[Range[n], {}] (* isolated vertices *)


The documentation on Automorphisms[] says:

Needs["Combinatorica"]


But then I cannot apply it to g:

grp = Automorphisms[g]


And in fact after the Needs[] statement, the meaning of Graph[] changes (it turns red).

Is there some standard way to handle this situation? I am currently focussed on just that one function Automorphisms[], but clearly the issue can arise for many Combinatorica functions. (In fact, what I really want is the order of the automorphism group of a graph.)

Addendum. I ended up following Szabolcs recommendation, and connected to the IGraph library in R from Mathematica via RLink to count the automorphisms. One application of this may be found at this MathOverflow question. The set up and installation necessary is nontrivial. I thank Szabolcs for his guidance throughout, as I could never had gotten it all to work without his help.
• I don't think it's complicated. You just need to convert the built-in Graph type to a COmbinatorica graph using GraphUtilitiesToCombinatoricaGraph and then you can apply the Combinatorica functions. The complicated part for me is keeping Combinatorica out of the context path. That nasty ToCombinatoricaGraph keeps re-adding it. – Szabolcs Nov 7 '13 at 1:26