| 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 |  | 
| 11 | Redistribution and use in source and binary forms, with or without | 
| 12 | modification, are permitted provided that the following conditions | 
| 13 | are met: | 
| 14 |  | 
| 15 | 1. Redistributions of source code must retain the above copyright | 
| 16 | notice, this list of conditions and the following disclaimer. | 
| 17 |  | 
| 18 | 2. Redistributions in binary form must reproduce the above copyright | 
| 19 | notice, this list of conditions and the following disclaimer in the | 
| 20 | documentation and/or other materials provided with the distribution. | 
| 21 |  | 
| 22 | 3. The names of its contributors may not be used to endorse or promote | 
| 23 | products derived from this software without specific prior written | 
| 24 | permission. | 
| 25 |  | 
| 26 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | 
| 27 | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | 
| 28 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | 
| 29 | A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR | 
| 30 | CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | 
| 31 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | 
| 32 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | 
| 33 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | 
| 34 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | 
| 35 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | 
| 36 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
| 37 |  | 
| 38 |  | 
| 39 | Any feedback is very welcome. | 
| 40 | http://www.math.keio.ac.jp/matumoto/emt.html | 
| 41 | email: matumoto@math.keio.ac.jp | 
| 42 | */ | 
| 43 |  | 
| 44 | #include <stdio.h> | 
| 45 |  | 
| 46 | /* Period parameters */ | 
| 47 | #define N 624 | 
| 48 | #define M 397 | 
| 49 | #define MATRIX_A 0x9908b0dfUL   /* constant vector a */ | 
| 50 | #define UPPER_MASK 0x80000000UL /* most significant w-r bits */ | 
| 51 | #define LOWER_MASK 0x7fffffffUL /* least significant r bits */ | 
| 52 |  | 
| 53 | static unsigned long mt[N]; /* the array for the state vector  */ | 
| 54 | static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */ | 
| 55 |  | 
| 56 | /* initializes mt[N] with a seed */ | 
| 57 | void init_genrand(unsigned long s) | 
| 58 | { | 
| 59 | mt[0]= s & 0xffffffffUL; | 
| 60 | for (mti=1; mti<N; mti++) { | 
| 61 | mt[mti] = | 
| 62 | (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti); | 
| 63 | /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */ | 
| 64 | /* In the previous versions, MSBs of the seed affect   */ | 
| 65 | /* only MSBs of the array mt[].                        */ | 
| 66 | /* 2002/01/09 modified by Makoto Matsumoto             */ | 
| 67 | mt[mti] &= 0xffffffffUL; | 
| 68 | /* for >32 bit machines */ | 
| 69 | } | 
| 70 | } | 
| 71 |  | 
| 72 | /* initialize by an array with array-length */ | 
| 73 | /* init_key is the array for initializing keys */ | 
| 74 | /* key_length is its length */ | 
| 75 | void init_by_array(init_key, key_length) | 
| 76 | unsigned long init_key[], key_length; | 
| 77 | { | 
| 78 | int i, j, k; | 
| 79 | init_genrand(19650218UL); | 
| 80 | i=1; j=0; | 
| 81 | k = (N>key_length ? N : key_length); | 
| 82 | for (; k; k--) { | 
| 83 | mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL)) | 
| 84 | + init_key[j] + j; /* non linear */ | 
| 85 | mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */ | 
| 86 | i++; j++; | 
| 87 | if (i>=N) { mt[0] = mt[N-1]; i=1; } | 
| 88 | if (j>=key_length) j=0; | 
| 89 | } | 
| 90 | for (k=N-1; k; k--) { | 
| 91 | mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL)) | 
| 92 | - i; /* non linear */ | 
| 93 | mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */ | 
| 94 | i++; | 
| 95 | if (i>=N) { mt[0] = mt[N-1]; i=1; } | 
| 96 | } | 
| 97 |  | 
| 98 | mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */ | 
| 99 | } | 
| 100 |  | 
| 101 | /* generates a random number on [0,0xffffffff]-interval */ | 
| 102 | unsigned long genrand_int32(void) | 
| 103 | { | 
| 104 | unsigned long y; | 
| 105 | static unsigned long mag01[2]={0x0UL, MATRIX_A}; | 
| 106 | /* mag01[x] = x * MATRIX_A  for x=0,1 */ | 
| 107 |  | 
| 108 | if (mti >= N) { /* generate N words at one time */ | 
| 109 | int kk; | 
| 110 |  | 
| 111 | if (mti == N+1)   /* if init_genrand() has not been called, */ | 
| 112 | init_genrand(5489UL); /* a default initial seed is used */ | 
| 113 |  | 
| 114 | for (kk=0;kk<N-M;kk++) { | 
| 115 | y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK); | 
| 116 | mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1UL]; | 
| 117 | } | 
| 118 | for (;kk<N-1;kk++) { | 
| 119 | y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK); | 
| 120 | mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1UL]; | 
| 121 | } | 
| 122 | y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK); | 
| 123 | mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL]; | 
| 124 |  | 
| 125 | mti = 0; | 
| 126 | } | 
| 127 |  | 
| 128 | y = mt[mti++]; | 
| 129 |  | 
| 130 | /* Tempering */ | 
| 131 | y ^= (y >> 11); | 
| 132 | y ^= (y << 7) & 0x9d2c5680UL; | 
| 133 | y ^= (y << 15) & 0xefc60000UL; | 
| 134 | y ^= (y >> 18); | 
| 135 |  | 
| 136 | return y; | 
| 137 | } | 
| 138 |  | 
| 139 | /* generates a random number on [0,0x7fffffff]-interval */ | 
| 140 | long genrand_int31(void) | 
| 141 | { | 
| 142 | return (long)(genrand_int32()>>1); | 
| 143 | } | 
| 144 |  | 
| 145 | /* generates a random number on [0,1]-real-interval */ | 
| 146 | double genrand_real1(void) | 
| 147 | { | 
| 148 | return genrand_int32()*(1.0/4294967295.0); | 
| 149 | /* divided by 2^32-1 */ | 
| 150 | } | 
| 151 |  | 
| 152 | /* generates a random number on [0,1)-real-interval */ | 
| 153 | double genrand_real2(void) | 
| 154 | { | 
| 155 | return genrand_int32()*(1.0/4294967296.0); | 
| 156 | /* divided by 2^32 */ | 
| 157 | } | 
| 158 |  | 
| 159 | /* generates a random number on (0,1)-real-interval */ | 
| 160 | double genrand_real3(void) | 
| 161 | { | 
| 162 | return (((double)genrand_int32()) + 0.5)*(1.0/4294967296.0); | 
| 163 | /* divided by 2^32 */ | 
| 164 | } | 
| 165 |  | 
| 166 | /* generates a random number on [0,1) with 53-bit resolution*/ | 
| 167 | double genrand_res53(void) | 
| 168 | { | 
| 169 | unsigned long a=genrand_int32()>>5, b=genrand_int32()>>6; | 
| 170 | return(a*67108864.0+b)*(1.0/9007199254740992.0); | 
| 171 | } | 
| 172 | /* These real versions are due to Isaku Wada, 2002/01/09 added */ | 
| 173 |  | 
| 174 | int main(void) | 
| 175 | { | 
| 176 | int i; | 
| 177 | unsigned long init[4]={0x123, 0x234, 0x345, 0x456}, length=4; | 
| 178 | init_by_array(init, length); | 
| 179 | printf("1000 outputs of genrand_int32()\n"); | 
| 180 | for (i=0; i<1000; i++) { | 
| 181 | printf("%10lu ", genrand_int32()); | 
| 182 | if (i%5==4) printf("\n"); | 
| 183 | } | 
| 184 | printf("\n1000 outputs of genrand_real2()\n"); | 
| 185 | for (i=0; i<1000; i++) { | 
| 186 | printf("%10.8f ", genrand_real2()); | 
| 187 | if (i%5==4) printf("\n"); | 
| 188 | } | 
| 189 | return 0; | 
| 190 | } |