[sage-support] Re: Sums of Modular Symbols continuing saga

2011-09-01 Thread chris wuthrich
Hello Jack, typically you want sage: E = EllipticCurve(11a1) sage: m = 5 sage: ms = E.modular_symbol() sage: chi = DirichletGroup(m).0 sage: chi Dirichlet character modulo 5 of conductor 5 mapping 2 |-- zeta4 sage: sum( (chi^2)(a) * ms(a/m) for a in [1..(m-1)] ) 5 The symbol ms is already

[sage-support] Re: Sums of Modular Symbols

2011-08-02 Thread jack
Doug has successfully cleared up my confusion off-list. I now have working code. Best wishes, Jack Fearnley -- 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

[sage-support] Re: Sums of Modular Symbols

2011-08-01 Thread jack
On Jul 31, 10:35 pm, D. S. McNeil dsm...@gmail.com wrote: We would like to know if certain sums of modular symbols span the space. Is this the sort of thing you had in mind? sage: M=ModularSymbols(11,2);M Modular Symbols space of dimension 3 for Gamma_0(11) of weight 2 with sign 0 over

Re: [sage-support] Re: Sums of Modular Symbols

2011-08-01 Thread D. S. McNeil
Thanks for this.  There still seems to be a manual step in going from, say, s1 = 2*(1,8) - (1,9) to  s1 = 2*b[1] - b[2] I may be misunderstanding you. Are you saying you want to enter the line s1 = 2*(1,8)-(1,9) verbatim and have it work? That I don't think I can do (unless you're

Re: [sage-support] Re: Sums of Modular Symbols

2011-08-01 Thread D. S. McNeil
.. I suppose you could even add a convenience function def b(*x): return m[x] after which sage: s = [2*b(1,8) - b(1,9), : -b(1,0) + b(1,9), : -b(1,0) + b(1,8)] sage: s [2*(1,8) - (1,9), -(1,0) + (1,9), -(1,0) + (1,8)] would work. Doug -- To post to this group, send

[sage-support] Re: Sums of Modular Symbols

2011-08-01 Thread jack
On Aug 1, 11:10 pm, D. S. McNeil dsm...@gmail.com wrote: Thanks for this.  There still seems to be a manual step in going from, say, s1 = 2*(1,8) - (1,9) to  s1 = 2*b[1] - b[2] I may be misunderstanding you.  Are you saying you want to enter the line     s1 = 2*(1,8)-(1,9)