mirror of
https://github.com/vale981/arb
synced 2025-03-06 01:41:39 -05:00
56 lines
1.3 KiB
C
56 lines
1.3 KiB
C
/*
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Copyright (C) 2016 Arb authors
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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
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acb_hypgeom_gamma_lower(acb_t res, const acb_t s, const acb_t z, int regularized, slong prec)
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{
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acb_t s1, nz, t;
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if (!acb_is_finite(s) || !acb_is_finite(z))
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{
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acb_indeterminate(res);
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return;
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}
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acb_init(s1);
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acb_init(nz);
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acb_init(t);
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acb_add_ui(s1, s, 1, prec);
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acb_neg(nz, z);
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if (regularized == 0)
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{
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/* \gamma(s, z) = s^-1 z^s 1F1(s, 1+s, -z) */
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acb_hypgeom_m(res, s, s1, nz, 0, prec);
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acb_pow(t, z, s, prec);
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acb_mul(res, res, t, prec);
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acb_div(res, res, s, prec);
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}
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else if (regularized == 1)
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{
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/* P(s, z) = z^s \gamma^{*}(s, z) */
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acb_hypgeom_m(res, s, s1, nz, 1, prec);
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acb_pow(t, z, s, prec);
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acb_mul(res, res, t, prec);
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}
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else if (regularized == 2)
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{
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/* \gamma^{*}(s, z) */
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acb_hypgeom_m(res, s, s1, nz, 1, prec);
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}
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acb_clear(s1);
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acb_clear(nz);
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acb_clear(t);
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}
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