Dear Moritz Schmidt, > I was able to compute the number of isomorphism classes for quite a > number of groups that I am interested in. The only thing that didn't > work so far was to calculate the number of conjugacy classes of > subgroups of the Coxeter group B_6 (which is isomorphic to O(6) \cap > GL(6,Z)). I get the following error: > gap> G := WreathProduct(CyclicGroup(2), SymmetricGroup(6)); > <group of size 46080 with 3 generators> > gap> cc := ConjugacyClassesSubgroups(G);;
> Is this a bug? Or is GAP trying to say "too complicated, cannot do it"? Yes, it is a (very insubstantial) bug which I will fix. However what triggers it is the way your group G is represented -- this also makes the overall calculation much slower -- namely as an abstract wreath product. gap> G.1; WreathProductElement(f1,<identity> of ...,<identity> of ...,<identity> of ...,<identity\ > of ...,<identity> of ...,()) The reason for this is that `CyclicGroup(2)' produces a PC group by default. If you instead force a permutation group: gap> G := WreathProduct(CyclicGroup(IsPermGroup,2), SymmetricGroup(6)); <permutation group of size 46080 with 8 generators> The calculation should go fine. (about 40 sec. on my system, 7440 classes) Regards, Alexander Hulpke _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
