arb/acb_modular/elliptic_e.c

59 lines
1.7 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) 2015 Fredrik Johansson
******************************************************************************/
#include "acb_modular.h"
void
acb_modular_elliptic_e(acb_t res, const acb_t m, slong prec)
{
if (acb_is_zero(m))
{
acb_const_pi(res, prec);
acb_mul_2exp_si(res, res, -1);
}
else if (acb_is_one(m))
{
acb_one(res);
}
else
{
acb_struct t[2];
acb_init(t + 0);
acb_init(t + 1);
acb_modular_elliptic_k_cpx(t, m, 2, prec);
acb_mul(t + 1, t + 1, m, prec);
acb_mul_2exp_si(t + 1, t + 1, 1);
acb_add(t, t, t + 1, prec);
acb_sub_ui(t + 1, m, 1, prec);
acb_mul(res, t, t + 1, prec);
acb_neg(res, res);
acb_clear(t + 0);
acb_clear(t + 1);
}
}