arb/arb_poly/sin_cos_series.c
2015-11-05 17:59:29 +00:00

89 lines
2.5 KiB
C

/*=============================================================================
This file is part of ARB.
ARB is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
ARB is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with ARB; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2013 Fredrik Johansson
******************************************************************************/
#include "arb_poly.h"
#define TANGENT_CUTOFF 240
void
_arb_poly_sin_cos_series(arb_ptr s, arb_ptr c, const arb_srcptr h, slong hlen, slong n, slong prec)
{
hlen = FLINT_MIN(hlen, n);
if (hlen == 1)
{
arb_sin_cos(s, c, h, prec);
_arb_vec_zero(s + 1, n - 1);
_arb_vec_zero(c + 1, n - 1);
}
else if (n == 2)
{
arb_t t;
arb_init(t);
arb_set(t, h + 1);
arb_sin_cos(s, c, h, prec);
arb_mul(s + 1, c, t, prec);
arb_neg(t, t);
arb_mul(c + 1, s, t, prec);
arb_clear(t);
}
else if (hlen < TANGENT_CUTOFF)
_arb_poly_sin_cos_series_basecase(s, c, h, hlen, n, prec, 0);
else
_arb_poly_sin_cos_series_tangent(s, c, h, hlen, n, prec, 0);
}
void
arb_poly_sin_cos_series(arb_poly_t s, arb_poly_t c,
const arb_poly_t h, slong n, slong prec)
{
slong hlen = h->length;
if (n == 0)
{
arb_poly_zero(s);
arb_poly_zero(c);
return;
}
if (hlen == 0)
{
arb_poly_zero(s);
arb_poly_one(c);
return;
}
if (hlen == 1)
n = 1;
arb_poly_fit_length(s, n);
arb_poly_fit_length(c, n);
_arb_poly_sin_cos_series(s->coeffs, c->coeffs, h->coeffs, hlen, n, prec);
_arb_poly_set_length(s, n);
_arb_poly_normalise(s);
_arb_poly_set_length(c, n);
_arb_poly_normalise(c);
}