pqc/external/flint-2.4.3/arith/test/t-chebyshev_t_polynomial.c
2014-05-24 23:16:06 +02:00

83 lines
2.3 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) 2011 Fredrik Johansson
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "arith.h"
#include "fmpz.h"
#include "fmpz_poly.h"
int main()
{
fmpz_poly_t T0, T1, T2, t;
slong n;
FLINT_TEST_INIT(state);
flint_printf("chebyshev_t_polynomial....");
fflush(stdout);
fmpz_poly_init(T0);
fmpz_poly_init(T1);
fmpz_poly_init(T2);
fmpz_poly_init(t);
arith_chebyshev_t_polynomial(T0, 0);
arith_chebyshev_t_polynomial(T1, 1);
for (n = 2; n <= 500; n++)
{
arith_chebyshev_t_polynomial(T2, n);
/* Verify T_{n+1} = 2 x T_n - T_{n-1} */
fmpz_poly_scalar_mul_ui(t, T1, UWORD(2));
fmpz_poly_shift_left(t, t, 1);
fmpz_poly_sub(t, t, T0);
if (!fmpz_poly_equal(t, T2))
{
flint_printf("FAIL: n = %wd\n", n);
flint_printf("t: "); fmpz_poly_print_pretty(t, "x"); flint_printf("\n");
flint_printf("T2: "); fmpz_poly_print_pretty(T2, "x"); flint_printf("\n");
abort();
}
fmpz_poly_swap(T0, T1);
fmpz_poly_swap(T1, T2);
}
fmpz_poly_clear(T0);
fmpz_poly_clear(T1);
fmpz_poly_clear(T2);
fmpz_poly_clear(t);
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return 0;
}