[GAP Forum] polycyclic group problem

[R.N. Tsai]

Dear gap forum,
 
I'm experimenting with the polycyclic package and ran into this problem.

This test program brings it out :
 
Test:=function(p)local collector,group,aut;
 # define group with 3 generators using polycyclic collector
 collector:=FromTheLeftCollector(3);
 SetCommutator(collector,2,1,[3,1]);
 SetRelativeOrder( collector, 1, p );
 SetRelativeOrder( collector, 2, p );
 SetRelativeOrder( collector, 3, p );
 # get size of group
 group:=PcpGroupByCollector(collector);
 Print(Size(group),"\n");
 # get size of automorphism group
 aut:=AutomorphismGroup(group);
 Print(Size(aut),"\n");
end;
 
the results are :
 
# no problems for p=2
gap> Test(2);
8
8
 
# no problems for p=4
gap> Test(3);
27
432
 
# with p=4 we get :
gap> Test(4);
64
Error, no method found! For debugging hints type ?Recovery from NoMethodFound
Error, no 2nd choice method found for `InducedPcgsByGeneratorsNC' on 2 argumen\
ts called from
InducedPcgsByGeneratorsNC( pcgs, gens ) called from
InducedPcgsByGenerators( pa, GeneratorsOfGroup( grp ) ) called from
Pcgs( group ) called from
SpecialPcgs( G ) called from
MinimalGeneratingSet( Image( gens ) ) called from
...
Entering break read-eval-print loop ...
you can 'quit;' to quit to outer loop, or
you can 'return;' to continue
brk> quit;
 
I think the group is "better behaved" when p is prime, but I would think it should
still be possible to get the automorphism group for the nonprime case.
 
Thanks,
 
R.N.
 

		
---------------------------------
 Sell on Yahoo! Auctions  - No fees. Bid on great items.