arb/fmprb_poly/log_gamma_series.c
2012-09-10 10:35:11 +02:00

47 lines
1.6 KiB
C

/*=============================================================================
This file is part of ARB.
ARB is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
ARB is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with ARB; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2012 Fredrik Johansson
******************************************************************************/
#include "fmprb_poly.h"
/* series expansion for log(gamma(1-x)) at x = 0 */
void
fmprb_poly_log_gamma_series(fmprb_poly_t z, long n, long prec)
{
long i;
fmprb_poly_fit_length(z, n);
_fmprb_poly_set_length(z, n);
if (n > 0) fmprb_zero(z->coeffs);
if (n > 1) fmprb_const_euler_brent_mcmillan(z->coeffs + 1, prec);
if (n > 2) fmprb_zeta_ui_vec(z->coeffs + 2, 2, n - 2, prec);
for (i = 2; i < n; i++)
fmprb_div_ui(z->coeffs + i, z->coeffs + i, i, prec);
_fmprb_poly_normalise(z);
}