mirror of
https://github.com/vale981/arb
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47 lines
1,022 B
C
47 lines
1,022 B
C
/*
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Copyright (C) 2021 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 "acb_hypgeom.h"
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void _arb_increment_fast(arb_t x, slong prec);
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void
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acb_hypgeom_rising_ui_forward(acb_t res, const acb_t x, ulong n, slong prec)
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{
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acb_t t;
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ulong k;
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slong wp;
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if (n <= 1)
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{
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if (n == 0)
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acb_one(res);
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else
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acb_set_round(res, x, prec);
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return;
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}
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wp = prec + FLINT_BIT_COUNT(n);
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acb_init(t);
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acb_add_ui(t, x, 1, wp);
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acb_mul(res, x, t, (n == 2) ? prec : wp);
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for (k = 2; k < n; k++)
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{
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_arb_increment_fast(acb_realref(t), wp);
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acb_mul(res, res, t, k == (n - 1) ? prec : wp);
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}
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acb_clear(t);
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}
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