arb/acb_hypgeom/rising_ui_rec.c

54 lines
1.3 KiB
C

/*
Copyright (C) 2021 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 "arb_hypgeom.h"
#include "acb_hypgeom.h"
void
acb_hypgeom_rising_ui_rec(acb_t res, const acb_t x, ulong n, slong prec)
{
if (n <= 1)
{
if (n == 0)
acb_one(res);
else
acb_set_round(res, x, prec);
return;
}
if (arb_is_zero(acb_imagref(x)))
{
arb_hypgeom_rising_ui_rec(acb_realref(res), acb_realref(x), n, prec);
arb_zero(acb_imagref(res));
return;
}
if (n == 2 && prec <= 1024)
{
if (res != x)
acb_set(res, x);
acb_addmul(res, x, x, prec);
return;
}
if (n <= 5 && prec <= 512)
{
acb_hypgeom_rising_ui_forward(res, x, n, prec);
}
else
{
if (n >= 20 && acb_bits(x) < prec / 8)
acb_hypgeom_rising_ui_bs(res, x, n, prec);
else
acb_hypgeom_rising_ui_rs(res, x, n, 0, prec);
}
}