shuuji3.xyz
[READ-ONLY] Mirror of https://github.com/shuuji3/python-extension-twister. Experimental Python C extension to generate random numbers by using Mersenne twister
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175 lines
1/*
2 A C-program for MT19937, with initialization improved 2002/1/26.
3 Coded by Takuji Nishimura and Makoto Matsumoto.
4
5 Before using, initialize the state by using init_genrand(seed)
6 or init_by_array(init_key, key_length).
7
8 Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
9 All rights reserved.
10 Copyright (C) 2005, Mutsuo Saito,
11 All rights reserved.
12
13 Redistribution and use in source and binary forms, with or without
14 modification, are permitted provided that the following conditions
15 are met:
16
17 1. Redistributions of source code must retain the above copyright
18 notice, this list of conditions and the following disclaimer.
19
20 2. Redistributions in binary form must reproduce the above copyright
21 notice, this list of conditions and the following disclaimer in the
22 documentation and/or other materials provided with the distribution.
23
24 3. The names of its contributors may not be used to endorse or promote
25 products derived from this software without specific prior written
26 permission.
27
28 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
32 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
33 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
34 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
35 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
36 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
37 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
38 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39
40
41 Any feedback is very welcome.
42 http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
43 email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
44*/
45
46#include <stdio.h>
47#include "mt19937ar.h"
48
49/* Period parameters */
50#define N 624
51#define M 397
52#define MATRIX_A 0x9908b0dfUL /* constant vector a */
53#define UPPER_MASK 0x80000000UL /* most significant w-r bits */
54#define LOWER_MASK 0x7fffffffUL /* least significant r bits */
55
56static unsigned long mt[N]; /* the array for the state vector */
57static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */
58
59/* initializes mt[N] with a seed */
60void init_genrand(unsigned long s)
61{
62 mt[0]= s & 0xffffffffUL;
63 for (mti=1; mti<N; mti++) {
64 mt[mti] =
65 (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti);
66 /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
67 /* In the previous versions, MSBs of the seed affect */
68 /* only MSBs of the array mt[]. */
69 /* 2002/01/09 modified by Makoto Matsumoto */
70 mt[mti] &= 0xffffffffUL;
71 /* for >32 bit machines */
72 }
73}
74
75/* initialize by an array with array-length */
76/* init_key is the array for initializing keys */
77/* key_length is its length */
78/* slight change for C++, 2004/2/26 */
79void init_by_array(unsigned long init_key[], int key_length)
80{
81 int i, j, k;
82 init_genrand(19650218UL);
83 i=1; j=0;
84 k = (N>key_length ? N : key_length);
85 for (; k; k--) {
86 mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL))
87 + init_key[j] + j; /* non linear */
88 mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
89 i++; j++;
90 if (i>=N) { mt[0] = mt[N-1]; i=1; }
91 if (j>=key_length) j=0;
92 }
93 for (k=N-1; k; k--) {
94 mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL))
95 - i; /* non linear */
96 mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
97 i++;
98 if (i>=N) { mt[0] = mt[N-1]; i=1; }
99 }
100
101 mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
102}
103
104/* generates a random number on [0,0xffffffff]-interval */
105unsigned long genrand_int32(void)
106{
107 unsigned long y;
108 static unsigned long mag01[2]={0x0UL, MATRIX_A};
109 /* mag01[x] = x * MATRIX_A for x=0,1 */
110
111 if (mti >= N) { /* generate N words at one time */
112 int kk;
113
114 if (mti == N+1) /* if init_genrand() has not been called, */
115 init_genrand(5489UL); /* a default initial seed is used */
116
117 for (kk=0;kk<N-M;kk++) {
118 y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
119 mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1UL];
120 }
121 for (;kk<N-1;kk++) {
122 y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
123 mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
124 }
125 y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
126 mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL];
127
128 mti = 0;
129 }
130
131 y = mt[mti++];
132
133 /* Tempering */
134 y ^= (y >> 11);
135 y ^= (y << 7) & 0x9d2c5680UL;
136 y ^= (y << 15) & 0xefc60000UL;
137 y ^= (y >> 18);
138
139 return y;
140}
141
142/* generates a random number on [0,0x7fffffff]-interval */
143long genrand_int31(void)
144{
145 return (long)(genrand_int32()>>1);
146}
147
148/* generates a random number on [0,1]-real-interval */
149double genrand_real1(void)
150{
151 return genrand_int32()*(1.0/4294967295.0);
152 /* divided by 2^32-1 */
153}
154
155/* generates a random number on [0,1)-real-interval */
156double genrand_real2(void)
157{
158 return genrand_int32()*(1.0/4294967296.0);
159 /* divided by 2^32 */
160}
161
162/* generates a random number on (0,1)-real-interval */
163double genrand_real3(void)
164{
165 return (((double)genrand_int32()) + 0.5)*(1.0/4294967296.0);
166 /* divided by 2^32 */
167}
168
169/* generates a random number on [0,1) with 53-bit resolution*/
170double genrand_res53(void)
171{
172 unsigned long a=genrand_int32()>>5, b=genrand_int32()>>6;
173 return(a*67108864.0+b)*(1.0/9007199254740992.0);
174}
175/* These real versions are due to Isaku Wada, 2002/01/09 added */