mirror of
https://github.com/vale981/arb
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57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
/*
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Copyright (C) 2017 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.h"
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void
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acb_sech(acb_t res, const acb_t z, slong prec)
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{
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if (arb_is_zero(acb_imagref(z)))
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{
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arb_sech(acb_realref(res), acb_realref(z), prec);
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arb_zero(acb_imagref(res));
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}
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else if (arb_is_zero(acb_realref(z)))
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{
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arb_sec(acb_realref(res), acb_imagref(z), prec);
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arb_zero(acb_imagref(res));
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}
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else
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{
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if (arf_cmpabs_2exp_si(arb_midref(acb_realref(z)), 0) > 0)
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{
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acb_t t;
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acb_init(t);
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if (arf_sgn(arb_midref(acb_realref(z))) > 0)
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{
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acb_neg(t, z);
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acb_exp(t, t, prec + 4);
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}
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else
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{
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acb_exp(t, z, prec + 4);
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}
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acb_mul(res, t, t, prec + 4);
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acb_add_ui(res, res, 1, prec + 4);
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acb_div(res, t, res, prec);
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acb_mul_2exp_si(res, res, 1);
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acb_clear(t);
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}
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else
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{
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acb_cosh(res, z, prec + 4);
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acb_inv(res, res, prec);
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}
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}
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}
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