arb/acb_elliptic/p_jet.c

93 lines
2.2 KiB
C

/*
Copyright (C) 2014 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"
#include "acb_poly.h"
void
acb_elliptic_p_jet(acb_ptr r, const acb_t z, const acb_t tau, slong len, slong prec)
{
acb_t t01, t02, t03, t04;
acb_ptr tz1, tz2, tz3, tz4;
acb_t t;
int real;
slong k;
if (len < 1)
return;
if (len == 1)
{
acb_elliptic_p(r, z, tau, prec);
return;
}
real = acb_is_real(z) && arb_is_int_2exp_si(acb_realref(tau), -1) &&
arb_is_positive(acb_imagref(tau));
acb_init(t);
acb_init(t01);
acb_init(t02);
acb_init(t03);
acb_init(t04);
tz1 = _acb_vec_init(len);
tz2 = _acb_vec_init(len);
tz3 = _acb_vec_init(len);
tz4 = _acb_vec_init(len);
acb_modular_theta_jet(tz1, tz2, tz3, tz4, z, tau, len, prec);
/* [theta_4(z) / theta_1(z)]^2 */
_acb_poly_div_series(tz2, tz4, len, tz1, len, len, prec);
_acb_poly_mullow(tz1, tz2, len, tz2, len, len, prec);
acb_zero(t);
acb_modular_theta(t01, t02, t03, t04, t, tau, prec);
/* [theta_2(0) * theta_3(0)] ^2 */
acb_mul(t, t02, t03, prec);
acb_mul(t, t, t, prec);
_acb_vec_scalar_mul(tz1, tz1, len, t, prec);
/* - [theta_2(0)^4 + theta_3(0)^4] / 3 */
acb_pow_ui(t02, t02, 4, prec);
acb_pow_ui(t03, t03, 4, prec);
acb_add(t, t02, t03, prec);
acb_div_ui(t, t, 3, prec);
acb_sub(tz1, tz1, t, prec);
/* times pi^2 */
acb_const_pi(t, prec);
acb_mul(t, t, t, prec);
_acb_vec_scalar_mul(r, tz1, len, t, prec);
if (real)
{
for (k = 0; k < len; k++)
arb_zero(acb_imagref(r + k));
}
acb_clear(t);
acb_clear(t01);
acb_clear(t02);
acb_clear(t03);
acb_clear(t04);
_acb_vec_clear(tz1, len);
_acb_vec_clear(tz2, len);
_acb_vec_clear(tz3, len);
_acb_vec_clear(tz4, len);
}