arb/acb_dirichlet/chi_theta_arb.c
2016-09-06 14:33:53 +02:00

62 lines
2 KiB
C

/*=============================================================================
This file is part of ARB.
ARB is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
ARB is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with ARB; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2016 Pascal Molin
******************************************************************************/
#include "acb_dirichlet.h"
#include "acb_poly.h"
/* x = Pi / q * t^2 */
static void
acb_dirichlet_arb_theta_argt(arb_t x, ulong q, const arb_t t, slong prec)
{
arb_const_pi(x, prec);
arb_div_ui(x, x, q, prec);
arb_mul(x, x, t, prec);
arb_mul(x, x, t, prec);
arb_neg(x, x);
arb_exp(x, x, prec);
}
void
acb_dirichlet_chi_theta_arb(acb_t res, const acb_dirichlet_group_t G, const acb_dirichlet_char_t chi, const arb_t t, slong prec)
{
slong len;
ulong * a;
arb_t x;
acb_dirichlet_powers_t z;
len = acb_dirichlet_theta_length(G->q, t, prec);
a = flint_malloc(len * sizeof(ulong));
acb_dirichlet_ui_chi_vec(a, G, chi, len);
acb_dirichlet_powers_init(z, chi->order, len, prec);
arb_init(x);
acb_dirichlet_arb_theta_argt(x, G->q, t, prec);
acb_dirichlet_arb_theta_naive(res, x, chi->parity, a, z, len, prec);
arb_clear(x);
flint_free(a);
acb_dirichlet_powers_clear(z);
}