arb/acb_dirichlet/chi.c
2016-10-08 20:54:14 +02:00

31 lines
910 B
C

/*
Copyright (C) 2015 Jonathan Bober
Copyright (C) 2016 Fredrik Johansson
Copyright (C) 2016 Pascal Molin
This file is part of Arb.
Arb is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "acb_dirichlet.h"
void
acb_dirichlet_chi(acb_t res, const dirichlet_group_t G, const dirichlet_char_t chi, ulong n, slong prec)
{
ulong expo;
expo = dirichlet_chi(G, chi, n);
if (expo == DIRICHLET_CHI_NULL)
acb_zero(res);
else
{
fmpq_t t;
fmpq_init(t);
fmpq_set_si(t, 2 * expo , G->expo);
arb_sin_cos_pi_fmpq(acb_imagref(res), acb_realref(res), t, prec);
fmpq_clear(t);
}
}