arb/acb_elliptic/p_prime.c
2021-05-22 18:50:30 +02:00

58 lines
1.4 KiB
C

/*
Copyright (C) 2021 Daniel Schultz
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_p_prime(acb_t r, const acb_t z, const acb_t tau, slong prec)
{
acb_struct tz[4];
acb_t t1, t2, t3;
int i, real;
real = acb_is_real(z) && arb_is_int_2exp_si(acb_realref(tau), -1) &&
arb_is_positive(acb_imagref(tau));
acb_init(t1);
acb_init(t2);
acb_init(t3);
for (i = 0; i < 4; i++)
acb_init(tz + i);
acb_modular_theta(tz + 0, tz + 1, tz + 2, tz + 3, z, tau, prec);
/* (-2*pi*eta^2/theta1)^3*theta2*theta3*theta4 */
acb_const_pi(t2, prec);
acb_mul_2exp_si(t2, t2, 1);
acb_neg(t2, t2);
acb_modular_eta(t3, tau, prec);
acb_mul(t1, t3, t3, prec);
acb_mul(t3, t1, t2, prec);
acb_div(t1, t3, tz + 0, prec);
acb_mul(t2, t1, t1, prec);
acb_mul(t3, t1, t2, prec);
acb_mul(t1, tz + 1, tz + 2, prec);
acb_mul(t2, t1, tz + 3, prec);
acb_mul(r, t3, t2, prec);
if (real)
arb_zero(acb_imagref(r));
acb_clear(t1);
acb_clear(t2);
acb_clear(t3);
for (i = 0; i < 4; i++)
acb_clear(tz + i);
}