53 lines
1.5 KiB
C
53 lines
1.5 KiB
C
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/*=============================================================================
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This file is part of FLINT.
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FLINT 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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FLINT 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 FLINT; 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) 2011 Fredrik Johansson
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******************************************************************************/
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#include <math.h>
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#include <gmp.h>
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#include "flint.h"
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#include "fmpz.h"
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#include "ulong_extras.h"
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double
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fmpz_dlog(const fmpz_t x)
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{
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if (!COEFF_IS_MPZ(*x))
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{
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return log(*x);
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}
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else
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{
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double s;
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slong e;
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#if defined(__MPIR_VERSION)
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s = mpz_get_d_2exp(&e, COEFF_TO_PTR(*x));
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#else
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s = mpz_get_d_2exp((long *) &e, COEFF_TO_PTR(*x));
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#endif
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return log(s) + e * 0.69314718055994530942;
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}
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}
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