93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
|
/*=============================================================================
|
||
|
|
|
||
|
|
This file is part of FLINT.
|
||
|
|
|
||
|
|
FLINT 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.
|
||
|
|
|
||
|
|
FLINT 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 FLINT; if not, write to the Free Software
|
||
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
||
|
|
|
||
|
|
=============================================================================*/
|
||
|
|
/******************************************************************************
|
||
|
|
|
||
|
|
Copyright (C) 2010 Sebastian Pancratz
|
||
|
|
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
#include <gmp.h>
|
||
|
|
#include "flint.h"
|
||
|
|
#include "fmpz.h"
|
||
|
|
#include "fmpz_vec.h"
|
||
|
|
#include "fmpz_poly.h"
|
||
|
|
#include "fmpq_poly.h"
|
||
|
|
|
||
|
|
void
|
||
|
|
_fmpq_poly_rescale(fmpz * res, fmpz_t denr,
|
||
|
|
const fmpz * poly, const fmpz_t den, slong len,
|
||
|
|
const fmpz_t xnum, const fmpz_t xden)
|
||
|
|
{
|
||
|
|
if (len < WORD(2))
|
||
|
|
{
|
||
|
|
if (res != poly)
|
||
|
|
{
|
||
|
|
_fmpz_vec_set(res, poly, len);
|
||
|
|
fmpz_set(denr, den);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
slong i;
|
||
|
|
fmpz_t t;
|
||
|
|
|
||
|
|
fmpz_init(t);
|
||
|
|
|
||
|
|
fmpz_one(t);
|
||
|
|
fmpz_set(res, poly);
|
||
|
|
for (i = WORD(1); i < len; i++)
|
||
|
|
{
|
||
|
|
fmpz_mul(t, t, xnum);
|
||
|
|
fmpz_mul(res + i, poly + i, t);
|
||
|
|
}
|
||
|
|
fmpz_one(t);
|
||
|
|
for (i = len - WORD(2); i >= WORD(0); i--)
|
||
|
|
{
|
||
|
|
fmpz_mul(t, t, xden);
|
||
|
|
fmpz_mul(res + i, res + i, t);
|
||
|
|
}
|
||
|
|
fmpz_mul(denr, den, t);
|
||
|
|
|
||
|
|
fmpz_clear(t);
|
||
|
|
|
||
|
|
_fmpq_poly_canonicalise(res, denr, len);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void fmpq_poly_rescale(fmpq_poly_t res, const fmpq_poly_t poly, const fmpq_t x)
|
||
|
|
{
|
||
|
|
if (fmpq_is_zero(x))
|
||
|
|
{
|
||
|
|
fmpq_poly_zero(res);
|
||
|
|
}
|
||
|
|
else if (poly->length < WORD(2))
|
||
|
|
{
|
||
|
|
fmpq_poly_set(res, poly);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
fmpq_poly_fit_length(res, poly->length);
|
||
|
|
_fmpq_poly_rescale(res->coeffs, res->den,
|
||
|
|
poly->coeffs, poly->den, poly->length,
|
||
|
|
fmpq_numref(x), fmpq_denref(x));
|
||
|
|
_fmpq_poly_set_length(res, poly->length);
|
||
|
|
}
|
||
|
|
}
|