arb/acb/log.c

99 lines
2.5 KiB
C

/*
Copyright (C) 2012 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.h"
void
acb_log(acb_t r, const acb_t z, slong prec)
{
#define a acb_realref(z)
#define b acb_imagref(z)
if (arb_is_zero(b))
{
if (arb_is_positive(a))
{
arb_log(acb_realref(r), a, prec);
arb_zero(acb_imagref(r));
}
else if (arb_is_negative(a))
{
arb_neg(acb_realref(r), a);
arb_log(acb_realref(r), acb_realref(r), prec);
arb_const_pi(acb_imagref(r), prec);
}
else
{
acb_indeterminate(r);
}
}
else if (arb_is_zero(a))
{
if (arb_is_positive(b))
{
arb_log(acb_realref(r), b, prec);
arb_const_pi(acb_imagref(r), prec);
arb_mul_2exp_si(acb_imagref(r), acb_imagref(r), -1);
}
else if (arb_is_negative(b))
{
arb_neg(acb_realref(r), b);
arb_log(acb_realref(r), acb_realref(r), prec);
arb_const_pi(acb_imagref(r), prec);
arb_mul_2exp_si(acb_imagref(r), acb_imagref(r), -1);
arb_neg(acb_imagref(r), acb_imagref(r));
}
else
{
acb_indeterminate(r);
}
}
else
{
if (r != z)
{
arb_log_hypot(acb_realref(r), a, b, prec);
if (arb_is_finite(acb_realref(r)))
arb_atan2(acb_imagref(r), b, a, prec);
else
arb_indeterminate(acb_imagref(r));
}
else
{
arb_t t;
arb_init(t);
arb_log_hypot(t, a, b, prec);
if (arb_is_finite(t))
arb_atan2(acb_imagref(r), b, a, prec);
else
arb_indeterminate(acb_imagref(r));
arb_swap(acb_realref(r), t);
arb_clear(t);
}
}
#undef a
#undef b
}
void
acb_log_analytic(acb_ptr res, const acb_t z, int analytic, slong prec)
{
if (analytic && arb_contains_zero(acb_imagref(z)) &&
!arb_is_positive(acb_realref(z)))
{
acb_indeterminate(res);
}
else
{
acb_log(res, z, prec);
}
}