arb/arb_poly/taylor_shift_divconquer.c

59 lines
1.7 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) 2016 Fredrik Johansson
******************************************************************************/
#include "arb_poly.h"
void
_arb_poly_taylor_shift_divconquer(arb_ptr poly, const arb_t c, slong len, slong prec)
{
arb_struct d[2];
if (len <= 1 || arb_is_zero(c))
return;
if (len == 2)
{
arb_addmul(poly, poly + 1, c, prec);
return;
}
d[0] = *c;
arb_init(d + 1);
arb_one(d + 1); /* no need to free */
_arb_poly_compose_divconquer(poly, poly, len, d, 2, prec);
}
void
arb_poly_taylor_shift_divconquer(arb_poly_t g, const arb_poly_t f,
const arb_t c, slong prec)
{
if (f != g)
arb_poly_set_round(g, f, prec);
_arb_poly_taylor_shift_divconquer(g->coeffs, c, g->length, prec);
}