arb/acb_elliptic/roots.c

50 lines
1.2 KiB
C

/*
Copyright (C) 2017 Fredrik Johansson
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_elliptic.h"
#include "acb_modular.h"
void
acb_elliptic_roots(acb_t e1, acb_t e2, acb_t e3, const acb_t tau, slong prec)
{
acb_t t1, t2, t3, t4;
acb_init(t1);
acb_init(t2);
acb_init(t3);
acb_init(t4);
acb_modular_theta(t1, t2, t3, t4, t1, tau, prec);
acb_pow_ui(t2, t2, 4, prec);
acb_pow_ui(t4, t4, 4, prec);
acb_sub(e2, t2, t4, prec);
acb_mul_2exp_si(t3, t4, 1);
acb_add(e1, t2, t3, prec);
acb_mul_2exp_si(t3, t2, 1);
acb_add(e3, t3, t4, prec);
acb_const_pi(t3, prec);
acb_mul(t3, t3, t3, prec);
acb_div_ui(t3, t3, 3, prec);
acb_mul(e1, e1, t3, prec);
acb_mul(e2, e2, t3, prec);
acb_mul(e3, e3, t3, prec);
acb_neg(e3, e3);
acb_clear(t1);
acb_clear(t2);
acb_clear(t3);
acb_clear(t4);
}