1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/* rng/tt.c
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000 James Theiler, Brian Gough
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <config.h>
#include <stdlib.h>
#include <gsl/gsl_rng.h>
/* This is the TT800 twisted GSFR generator for 32 bit integers. It
has been superceded by MT19937 (mt.c). The period is 2^800.
This implementation is based on tt800.c, July 8th 1996 version by
M. Matsumoto, email: matumoto@math.keio.ac.jp
From: Makoto Matsumoto and Yoshiharu Kurita, "Twisted GFSR
Generators II", ACM Transactions on Modelling and Computer
Simulation, Vol. 4, No. 3, 1994, pages 254-266. */
static inline unsigned long int tt_get (void *vstate);
static double tt_get_double (void *vstate);
static void tt_set (void *state, unsigned long int s);
#define N 25
#define M 7
typedef struct
{
int n;
unsigned long int x[N];
}
tt_state_t;
static inline unsigned long int
tt_get (void *vstate)
{
tt_state_t *state = (tt_state_t *) vstate;
/* this is the magic vector, a */
const unsigned long mag01[2] =
{0x00000000, 0x8ebfd028UL};
unsigned long int y;
unsigned long int *const x = state->x;
int n = state->n;
if (n >= N)
{
int i;
for (i = 0; i < N - M; i++)
{
x[i] = x[i + M] ^ (x[i] >> 1) ^ mag01[x[i] % 2];
}
for (; i < N; i++)
{
x[i] = x[i + (M - N)] ^ (x[i] >> 1) ^ mag01[x[i] % 2];
};
n = 0;
}
y = x[n];
y ^= (y << 7) & 0x2b5b2500UL; /* s and b, magic vectors */
y ^= (y << 15) & 0xdb8b0000UL; /* t and c, magic vectors */
y &= 0xffffffffUL; /* you may delete this line if word size = 32 */
/* The following line was added by Makoto Matsumoto in the 1996
version to improve lower bit's correlation. Delete this line
to use the code published in 1994. */
y ^= (y >> 16); /* added to the 1994 version */
state->n = n + 1;
return y;
}
static double
tt_get_double (void * vstate)
{
return tt_get (vstate) / 4294967296.0 ;
}
static void
tt_set (void *vstate, unsigned long int s)
{
tt_state_t *state = (tt_state_t *) vstate;
const tt_state_t init_state =
{0,
{0x95f24dabUL, 0x0b685215UL, 0xe76ccae7UL,
0xaf3ec239UL, 0x715fad23UL, 0x24a590adUL,
0x69e4b5efUL, 0xbf456141UL, 0x96bc1b7bUL,
0xa7bdf825UL, 0xc1de75b7UL, 0x8858a9c9UL,
0x2da87693UL, 0xb657f9ddUL, 0xffdc8a9fUL,
0x8121da71UL, 0x8b823ecbUL, 0x885d05f5UL,
0x4e20cd47UL, 0x5a9ad5d9UL, 0x512c0c03UL,
0xea857ccdUL, 0x4cc1d30fUL, 0x8891a8a1UL,
0xa6b7aadbUL}};
if (s == 0) /* default seed is given explicitly in the original code */
{
*state = init_state;
}
else
{
int i;
state->n = 0;
state->x[0] = s & 0xffffffffUL;
for (i = 1; i < N; i++)
state->x[i] = (69069 * state->x[i - 1]) & 0xffffffffUL;
}
return;
}
static const gsl_rng_type tt_type =
{"tt800", /* name */
0xffffffffUL, /* RAND_MAX */
0, /* RAND_MIN */
sizeof (tt_state_t),
&tt_set,
&tt_get,
&tt_get_double};
const gsl_rng_type *gsl_rng_tt800 = &tt_type;
|
