mirror of
https://github.com/vale981/arb
synced 2025-03-06 09:51:39 -05:00
101 lines
2.7 KiB
C
101 lines
2.7 KiB
C
/*=============================================================================
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This file is part of ARB.
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ARB 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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ARB 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 ARB; 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) 2012 Fredrik Johansson
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******************************************************************************/
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#include "fmprb_poly.h"
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void
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_fmprb_poly_neg(fmprb_struct * B, const fmprb_struct * A, long n, long prec)
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{
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long i;
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for (i = 0; i < n; i++)
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fmprb_neg(B + i, A + i);
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}
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void
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_fmprb_poly_inv_series(fmprb_struct * Qinv, const fmprb_struct * Q, long len, long prec)
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{
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long a[FLINT_BITS];
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long i, m, n;
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fmprb_struct * W;
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W = flint_malloc(len * sizeof(fmprb_struct));
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for (i = 0; i < len; i++)
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fmprb_init(W + i);
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a[i = 0] = n = len;
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while (n >= 2)
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a[++i] = (n = (n + 1) / 2);
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fmprb_ui_div(Qinv, 1UL, Q, prec);
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for (i--; i >= 0; i--)
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{
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m = n;
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n = a[i];
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_fmprb_poly_mullow(W, Q, n, Qinv, m, n, prec);
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_fmprb_poly_mullow(Qinv + m, Qinv, m, W + m, n - m, n - m, prec);
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_fmprb_poly_neg(Qinv + m, Qinv + m, n - m, prec);
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}
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for (i = 0; i < len; i++)
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fmprb_clear(W + i);
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flint_free(W);
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}
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void
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fmprb_poly_inv_series(fmprb_poly_t Qinv, const fmprb_poly_t Q, long n, long prec)
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{
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if (n == 0 || Q->length == 0)
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abort();
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if (Q->length < n || Qinv == Q)
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{
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long i;
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fmprb_poly_t t;
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fmprb_poly_init(t);
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fmprb_poly_fit_length(t, n);
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for (i = 0; i < FLINT_MIN(n, Q->length); i++)
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fmprb_set(t->coeffs + i, Q->coeffs + i);
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for (i = FLINT_MIN(n, Q->length); i < n; i++)
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fmprb_zero(t->coeffs + i);
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_fmprb_poly_set_length(t, n);
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fmprb_poly_inv_series(Qinv, t, n, prec);
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fmprb_poly_clear(t);
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return;
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}
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fmprb_poly_fit_length(Qinv, n);
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_fmprb_poly_inv_series(Qinv->coeffs, Q->coeffs, n, prec);
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_fmprb_poly_set_length(Qinv, n);
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_fmprb_poly_normalise(Qinv);
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}
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