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 at > http://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
