Dear Tom, Thanks for your answer! I get the empty set, too. I really wonder what is going on with the picture though... if one cannot "rely on the picture", then it pretty much defeats the purpose when it comes to Cayley graphs, doesn't it?
and i mean, there *is* a double arrow on some edges. thanks again, pierre On 13 mar, 13:50, Tom Boothby <tomas.boot...@gmail.com> wrote: > Pierre, > > Don't rely on the picture! > > sage: U = set(gr.edges()) > sage: V = set(gr.reverse().edges()) > sage: U.intersection(V) #for me, this is the empty set > > > > > > > > On Tue, Mar 13, 2012 at 3:26 AM, Pierre <pierre.guil...@gmail.com> wrote: > > Hi, > > > I've been playing with Cayley graphs in Sage (thanks to whoever > > implemented this!) I got funny results on one example, and I'd like to > > understand. > > > I've tried SL(2, ZZ): > > > sage: G= SL(2, ZZ) > > sage: S, T= G.gens(); ST= S*T > > sage: L= [S^i*ST^j for i in range(4) for j in range(3)] #S has order > > 4, ST has order 3 > > sage: els= Set([ a*b*c*d for a in L for b in L for c in L for d in L]) > > sage: gr= G.cayley_graph(generators = [S, ST], elements= els) > > sage: gr.show(color_by_label= True, iterations= 500, vertex_labels= > > False, vertex_size= 1, dpi= 800)) #for example > > > I don't know how to attach a picture to this message, so I'll have to > > describe the result as very close to the Cayley graph of PSL(2, ZZ) > > rather than SL(2, ZZ)!! it looks as if one of my generators has order > > 2!! > > > does anyone know what is going on? > > > thanks! > > Pierre > > > -- > > To post to this group, send email to sage-support@googlegroups.com > > To unsubscribe from this group, send email to > > sage-support+unsubscr...@googlegroups.com > > For more options, visit this group > > athttp://groups.google.com/group/sage-support > > URL:http://www.sagemath.org -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
