arb/acb_hypgeom/pfq_series_sum_rs.c
Tommy Hofmann 6bf072eb59 Replace abort with flint_abort.
This will allow us to not loose the julia session on error.
See also https://github.com/wbhart/flint2/pull/243
2017-02-28 16:52:57 +01:00

289 lines
7 KiB
C

/*
Copyright (C) 2016 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_hypgeom.h"
#define FAST_T 0
void acb_poly_reciprocal_majorant(arb_poly_t res, const acb_poly_t poly, slong prec);
static void
rsplit(acb_poly_t res, acb_poly_t term,
const acb_poly_struct * a, slong p,
const acb_poly_struct * b, slong q,
const acb_poly_t z, slong offset, slong n, slong len, slong prec)
{
acb_poly_struct * zpow;
acb_poly_t s, t, u;
slong i, j, k, m, tprec;
int is_real;
#if FAST_T
arb_poly_t B, C, D;
#else
acb_poly_t B, C, D;
#endif
if (n == 0)
{
acb_poly_zero(res);
acb_poly_one(term);
return;
}
if (n < 0)
flint_abort();
m = n_sqrt(n);
m = FLINT_MIN(m, 150);
acb_poly_init(s);
acb_poly_init(t);
acb_poly_init(u);
#if FAST_T
tprec = MAG_BITS;
arb_poly_init(B);
arb_poly_init(C);
arb_poly_init(D);
arb_poly_one(B);
arb_poly_one(D);
is_real = 1;
for (i = 0; i < p; i++)
for (j = 0; j < FLINT_MIN(acb_poly_length(a + i), len); j++)
is_real = is_real && acb_is_real((a + i)->coeffs + j);
for (i = 0; i < q; i++)
for (j = 0; j < FLINT_MIN(acb_poly_length(b + i), len); j++)
is_real = is_real && acb_is_real((b + i)->coeffs + j);
for (j = 0; j < FLINT_MIN(acb_poly_length(z), len); j++)
is_real = is_real && acb_is_real(z->coeffs + j);
#else
tprec = 2 * MAG_BITS;
is_real = 0; (void) is_real;
acb_poly_init(B);
acb_poly_init(C);
acb_poly_init(D);
acb_poly_one(B);
acb_poly_one(D);
#endif
zpow = flint_malloc(sizeof(acb_poly_struct) * (m + 1));
for (i = 0; i <= m; i++)
acb_poly_init(zpow + i);
for (i = 0; i <= m; i++)
{
if (i == 0)
acb_poly_one(zpow + i);
else if (i == 1)
acb_poly_set_round(zpow + i, z, prec);
else if (i % 2 == 0)
acb_poly_mullow(zpow + i, zpow + i / 2, zpow + i / 2, len, prec);
else
acb_poly_mullow(zpow + i, zpow + i - 1, zpow + 1, len, prec);
}
for (k = n; k >= 0; k--)
{
j = k % m;
if (k < n)
acb_poly_add(s, s, zpow + j, prec);
if (k > 0)
{
if (p > 0)
{
acb_poly_add_si(u, a, offset + k - 1, prec);
for (i = 1; i < p; i++)
{
acb_poly_add_si(t, a + i, offset + k - 1, prec);
acb_poly_mullow(u, u, t, len, prec);
}
if (k < n)
acb_poly_mullow(s, s, u, len, prec);
#if FAST_T
acb_poly_majorant(C, u, tprec);
arb_poly_mullow(B, B, C, len, tprec);
#else
acb_poly_set_round(C, u, tprec);
acb_poly_mullow(B, B, C, len, tprec);
#endif
}
if (q > 0)
{
acb_poly_add_si(u, b, offset + k - 1, prec);
for (i = 1; i < q; i++)
{
acb_poly_add_si(t, b + i, offset + k - 1, prec);
acb_poly_mullow(u, u, t, len, prec);
}
if (k < n)
acb_poly_div_series(s, s, u, len, prec);
#if FAST_T
acb_poly_reciprocal_majorant(C, u, tprec);
arb_poly_mullow(D, D, C, len, tprec);
#else
acb_poly_set_round(C, u, tprec);
acb_poly_mullow(D, D, C, len, tprec);
#endif
}
if (j == 0 && k < n)
{
acb_poly_mullow(s, s, zpow + m, len, prec);
}
}
}
#if FAST_T
arb_poly_div_series(B, B, D, len, tprec);
acb_poly_majorant(C, z, tprec);
arb_poly_pow_ui_trunc_binexp(C, C, n, len, tprec);
arb_poly_mullow(C, B, C, len, tprec);
acb_poly_fit_length(term, arb_poly_length(C));
for (i = 0; i < arb_poly_length(C); i++)
{
arb_get_mag(arb_radref(acb_realref(term->coeffs + i)), C->coeffs + i);
arf_zero(arb_midref(acb_realref(term->coeffs + i)));
if (is_real)
arb_zero(acb_imagref(term->coeffs + i));
else
arb_set(acb_imagref(term->coeffs + i), acb_realref(term->coeffs + i));
}
_acb_poly_set_length(term, arb_poly_length(C));
_acb_poly_normalise(term);
#else
acb_poly_div_series(B, B, D, len, tprec);
acb_poly_set_round(C, z, tprec);
acb_poly_pow_ui_trunc_binexp(C, C, n, len, tprec);
acb_poly_mullow(term, B, C, len, tprec);
#endif
acb_poly_set(res, s);
#if FAST_T
arb_poly_clear(B);
arb_poly_clear(C);
arb_poly_clear(D);
#else
acb_poly_clear(B);
acb_poly_clear(C);
acb_poly_clear(D);
#endif
acb_poly_clear(s);
acb_poly_clear(t);
acb_poly_clear(u);
for (i = 0; i <= m; i++)
acb_poly_clear(zpow + i);
flint_free(zpow);
}
void
acb_hypgeom_pfq_series_sum_rs(acb_poly_t s, acb_poly_t t,
const acb_poly_struct * a, slong p,
const acb_poly_struct * b, slong q,
const acb_poly_t z, int regularized,
slong n, slong len, slong prec)
{
acb_poly_t u, v;
slong i, start;
if (n == 0)
{
acb_hypgeom_pfq_series_sum_forward(s, t, a, p, b, q, z,
regularized, n, len, prec);
return;
}
start = 0;
if (regularized)
{
for (i = 0; i < q; i++)
{
if (acb_poly_is_zero(b + i))
{
start = FLINT_MAX(start, 1);
}
else
{
/* todo: use a fuzzier test? */
if (acb_contains_int((b + i)->coeffs) &&
!arb_is_positive(acb_realref((b + i)->coeffs)) &&
arf_cmpabs_2exp_si(arb_midref(acb_realref((b + i)->coeffs)),
FLINT_BITS - 2) < 0)
{
slong c = -arf_get_si(arb_midref(acb_realref((b + i)->coeffs)),
ARF_RND_NEAR);
/* if c >= n, terminates earlier, so no problem */
if (c < n)
{
start = FLINT_MAX(start, c + 1);
}
}
}
}
/* We should now have start <= n. */
if (start > n) flint_abort();
acb_hypgeom_pfq_series_sum_forward(s, t, a, p, b, q, z,
regularized, start, len, prec);
}
else
{
acb_poly_zero(s);
acb_poly_one(t);
}
if (start == n)
return;
acb_poly_init(u);
acb_poly_init(v);
rsplit(u, v, a, p, b, q, z, start, n - start, len, prec);
acb_poly_mullow(u, u, t, len, prec);
acb_poly_add(s, s, u, prec);
acb_poly_mullow(t, t, v, len, prec);
acb_poly_clear(u);
acb_poly_clear(v);
}