[Nauty-list] A question on nauty

[Mathieu Dutour]

Dear all,

I have a class of graph, which has the following property:
--S is a subset of the vertex set.
--If phi is an automorphism, then phi is is determined by its
  restriction to S.

Can thie property be used, in principle, to speed up automorphism
search?

The context is determination of automorphism group of lattices of
R^n or in other words of matrices P in GLn(Z) such that PA P^t=A
with A positive definite.
The method is to select a family of vectors (v_i)_{1 <= i <= M},
which we know to be invariant by the automorphism group and build
the edge colored graph v_i A v_j^t.
There is a classic software in this field, CARAT, which does the
job but in some cases nauty is superior to it despite the layers
of translation and I am searching for a way to combine both
strengths.

Thank you in advance for any help.
Best,

  Mathieu

-- 
Mathieu Dutour Sikiric		Researcher in Mathematics
Telephone:.(+385)1 4571 237	and Computer Science
Cell Phone: (+385)9 19 36 30 80	Laboratory of satellite oceanography
E-mail: Mathieu.Dutour at ens.fr	Rudjer Boskovic Institute
http://www.liga.ens.fr/~dutour	Zagreb Croatia
skype name: mathieudutour