3 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 James Theiler, Brian Gough
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 3 of the License, or (at
8 * your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
22 #include <gsl/gsl_rng.h>
24 /* This is the old vax generator MTH$RANDOM. The sequence is,
26 x_{n+1} = (a x_n + c) mod m
28 with a = 69069, c = 1 and m = 2^32. The seed specifies the initial
31 The theoretical value of x_{10001} is 3051034865.
33 The period of this generator is 2^32. */
35 static inline unsigned long int vax_get (void *vstate);
36 static double vax_get_double (void *vstate);
37 static void vax_set (void *state, unsigned long int s);
45 static inline unsigned long int
46 vax_get (void *vstate)
48 vax_state_t *state = (vax_state_t *) vstate;
50 state->x = (69069 * state->x + 1) & 0xffffffffUL;
56 vax_get_double (void *vstate)
58 return vax_get (vstate) / 4294967296.0 ;
62 vax_set (void *vstate, unsigned long int s)
64 vax_state_t *state = (vax_state_t *) vstate;
66 /* default seed is 0. The constant term c stops the series from
67 collapsing to 0,0,0,0,0,... */
74 static const gsl_rng_type vax_type =
76 0xffffffffUL, /* RAND_MAX */
83 const gsl_rng_type *gsl_rng_vax = &vax_type;