mirror of
https://github.com/vale981/arb
synced 2025-03-05 09:21:38 -05:00
66 lines
1.4 KiB
C
66 lines
1.4 KiB
C
/*
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Copyright (C) 2013 Fredrik Johansson
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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 it under
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the terms of the GNU Lesser General Public License (LGPL) as published
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by the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version. See <http://www.gnu.org/licenses/>.
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*/
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#include "arb_poly.h"
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void
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_arb_poly_cos_series(arb_ptr g, arb_srcptr h, slong hlen, slong n, slong prec)
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{
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hlen = FLINT_MIN(hlen, n);
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if (hlen == 1)
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{
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arb_cos(g, h, prec);
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_arb_vec_zero(g + 1, n - 1);
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}
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else if (n == 2)
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{
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arb_t t;
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arb_init(t);
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arb_sin_cos(t, g, h, prec);
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arb_neg(t, t);
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arb_mul(g + 1, h + 1, t, prec); /* safe since hlen >= 2 */
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arb_clear(t);
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}
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else
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{
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arb_ptr t = _arb_vec_init(n);
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_arb_poly_sin_cos_series(t, g, h, hlen, n, prec);
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_arb_vec_clear(t, n);
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}
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}
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void
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arb_poly_cos_series(arb_poly_t g, const arb_poly_t h, slong n, slong prec)
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{
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slong hlen = h->length;
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if (n == 0)
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{
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arb_poly_zero(g);
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return;
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}
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if (hlen == 0)
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{
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arb_poly_one(g);
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return;
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}
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if (hlen == 1)
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n = 1;
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arb_poly_fit_length(g, n);
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_arb_poly_cos_series(g->coeffs, h->coeffs, hlen, n, prec);
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_arb_poly_set_length(g, n);
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_arb_poly_normalise(g);
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}
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