3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 3 of the License, or (at
6 * your option) any later version.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19 * This generator is taken from
22 * The Art of Computer Programming
28 * It is called "Fishman"
30 * This implementation copyright (C) 2001 Carlo Perassi
31 * and (C) 2003 Heiko Bauke.
36 #include <gsl/gsl_rng.h>
38 static inline unsigned long int ran_get (void *vstate);
39 static double ran_get_double (void *vstate);
40 static void ran_set (void *state, unsigned long int s);
42 static const long int m = 2147483647, a = 48271, q = 44488, r = 3399;
50 static inline unsigned long int
51 ran_get (void *vstate)
53 ran_state_t *state = (ran_state_t *) vstate;
55 const unsigned long int x = state->x;
57 const long int h = x / q;
58 const long int t = a * (x - h * q) - h * r;
73 ran_get_double (void *vstate)
75 ran_state_t *state = (ran_state_t *) vstate;
77 return ran_get (state) / 2147483647.0;
81 ran_set (void *vstate, unsigned long int s)
83 ran_state_t *state = (ran_state_t *) vstate;
86 s = 1; /* default seed is 1 */
93 static const gsl_rng_type ran_type = {
94 "fishman20", /* name */
95 2147483646, /* RAND_MAX */
103 const gsl_rng_type *gsl_rng_fishman20 = &ran_type;