Dear Frédéric, dear all, On 20 December 2012 00:30, Frederic Vanhove <fvanh...@cage.ugent.be> wrote: > Hello, > > I have yet another question on (equivalent) group actions. > When I build an action on a set, is there way to have GAP store a > bijection between the original points on which he acts, and the labels > [1..v]? > > For instance, when I do: > > G:=SymmetricGroup(4); > g:=AutomorphismGroup(G); > act:=Action(g,G,OnPoints); > Orbits(act); > > the output in the end is: > [ [ 2, 7, 5, 21, 16, 13 ], [ 3, 11, 6, 9, 20, 4, 17, 14 ], > [ 8, 24, 23, 15, 10, 18 ], [ 12, 22, 19 ] ]
isn't the following what you need? gap> Orbits(g,G,OnPoints); [ [ () ], [ (1,4), (1,2), (2,4), (2,3), (1,3), (3,4) ], [ (1,2,4), (1,2,3), (1,4,2), (2,3,4), (1,3,2), (1,3,4), (2,4,3), (1,4,3) ], [ (1,3,4,2), (1,3,2,4), (1,2,3,4), (1,2,4,3), (1,4,2,3), (1,4,3,2) ], [ (1,3)(2,4), (1,4)(2,3), (1,2)(3,4) ] ] HTH, Dmitrii > > while elements of G itself look like (1,4)(2,3), and I would want the > orbits in that form. > (This is just an example, I had other more complicated sets in mind) > CONFIDENTIALITY:This email is intended solely for the person(s) named and may be confidential and/or privileged.If you are not the intended recipient,please delete it,notify us and do not copy,use,or disclose its content. Towards A Sustainable Earth:Print Only When Necessary.Thank you. _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
