[GAP Forum] Display(CharacterTable(G)); recursion depth trap (5000)

[Alexander Hulpke]

Dear Forum,


On May 25, 2012, at 5/25/12 12:57, Linda Cupples wrote:
> 
> F:=FreeGroup("a","b");
> a:=F.1;;b:=F.2;;
> G:=F/[a^4,b^4,(a*b)^2,(a^3*b)^2];
> Display(CharacterTable(G));

When doing involved calculations such as character table in general the representation of a group as a finitely presented group is the least efficient and provides least functionality.

This is the reason for the problem you observe. (The next release will provide somewhat better functionality and for example be able to do this example, but still it would be very inefficient to calculate the character table of a finitely presented group of order 10^6.)

The easiest way to deal with this issue thus is to move to an isomorphic permutation representation:
gap> P:=Image(IsomorphismPermGroup(G));
gap> Display(CharacterTable(P));

As this type of question comes up about every 6 months it might be a good opportunity to advertise the GAP Forum email archive at:

http://mail.gap-system.org/pipermail/forum/

as well.

Best wishes,

   Alexander Hulpke




-- Colorado State University, Department of Mathematics,
Weber Building, 1874 Campus Delivery, Fort Collins, CO 80523-1874, USA
email: hulpke at math.colostate.edu, Phone: ++1-970-4914288
http://www.math.colostate.edu/~hulpke