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

57 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) 2013 Fredrik Johansson
******************************************************************************/
#include "arb_poly.h"
void
_arb_poly_inv_borel_transform(arb_ptr res, arb_srcptr poly, slong len, slong prec)
{
slong i;
arb_t t;
arb_init(t);
arb_one(t);
for (i = 0; i < len; i++)
{
if (i > 1)
arb_mul_ui(t, t, i, prec);
arb_mul(res + i, poly + i, t, prec);
}
arb_clear(t);
}
void
arb_poly_inv_borel_transform(arb_poly_t res, const arb_poly_t poly, slong prec)
{
arb_poly_fit_length(res, poly->length);
_arb_poly_inv_borel_transform(res->coeffs, poly->coeffs, poly->length, prec);
_arb_poly_set_length(res, poly->length);
_arb_poly_normalise(res);
}