76 lines
2.0 KiB
C
76 lines
2.0 KiB
C
/*=============================================================================
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This file is part of FLINT.
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FLINT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FLINT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2011 Fredrik Johansson
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******************************************************************************/
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#include <stdlib.h>
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#include "flint.h"
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#include "fmpz_poly.h"
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#include "fmpz_poly_mat.h"
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void
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fmpz_poly_mat_det_interpolate(fmpz_poly_t det, const fmpz_poly_mat_t A)
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{
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slong i, l, n, len;
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fmpz_mat_t X;
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fmpz * x;
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fmpz * d;
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n = A->r;
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if (n == 0)
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{
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fmpz_poly_one(det);
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return;
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}
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l = fmpz_poly_mat_max_length(A);
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if (l == 0)
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{
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fmpz_poly_zero(det);
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return;
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}
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/* Bound degree based on Laplace expansion */
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len = n*(l - 1) + 1;
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x = _fmpz_vec_init(len);
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d = _fmpz_vec_init(len);
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fmpz_mat_init(X, n, n);
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for (i = 0; i < len; i++)
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{
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fmpz_set_si(x + i, -len/2 + i);
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fmpz_poly_mat_evaluate_fmpz(X, A, x + i);
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fmpz_mat_det(d + i, X);
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}
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fmpz_poly_interpolate_fmpz_vec(det, x, d, len);
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_fmpz_vec_clear(x, len);
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_fmpz_vec_clear(d, len);
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fmpz_mat_clear(X);
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}
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