/* A C-program for MT19937: Integer version */ /* genrand() generates one pseudorandom unsigned integer (32bit) */ /* which is uniformly distributed among 0 to 2^32-1 for each */ /* call. sgenrand(seed) set initial values to the working area */ /* of 624 words. Before genrand(), sgenrand(seed) must be */ /* called once. (seed is any 32-bit integer except for 0). */ /* Coded by Takuji Nishimura, considering the suggestions by */ /* Topher Cooper and Marc Rieffel in July-Aug. 1997. */ /* This library is free software; you can redistribute it and/or */ /* modify it under the terms of the GNU Library General Public */ /* License as published by the Free Software Foundation; either */ /* version 2 of the License, or (at your option) any later */ /* version. */ /* This library 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 Library General Public License for more details. */ /* You should have received a copy of the GNU Library General */ /* Public License along with this library; if not, write to the */ /* Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA */ /* 02111-1307 USA */ /* Copyright (C) 1997 Makoto Matsumoto and Takuji Nishimura. */ /* Any feedback is very welcome. For any question, comments, */ /* see http://www.math.keio.ac.jp/matumoto/emt.html or email */ /* matumoto@math.keio.ac.jp */ #include<stdio.h> /* Period parameters */ #define N 624 #define M 397 #define MATRIX_A 0x9908b0df /* constant vector a */ #define UPPER_MASK 0x80000000 /* most significant w-r bits */ #define LOWER_MASK 0x7fffffff /* least significant r bits */ /* Tempering parameters */ #define TEMPERING_MASK_B 0x9d2c5680 #define TEMPERING_MASK_C 0xefc60000 #define TEMPERING_SHIFT_U(y) (y >> 11) #define TEMPERING_SHIFT_S(y) (y << 7) #define TEMPERING_SHIFT_T(y) (y << 15) #define TEMPERING_SHIFT_L(y) (y >> 18) static unsigned long mt[N]; /* the array for the state vector */ static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */ /* initializing the array with a NONZERO seed */ void sgenrand(seed) unsigned long seed; { /* setting initial seeds to mt[N] using */ /* the generator Line 25 of Table 1 in */ /* [KNUTH 1981, The Art of Computer Programming */ /* Vol. 2 (2nd Ed.), pp102] */ mt[0]= seed & 0xffffffff; for (mti=1; mti<N; mti++) mt[mti] = (69069 * mt[mti-1]) & 0xffffffff; } unsigned long genrand() { unsigned long y; static unsigned long mag01[2]={0x0, MATRIX_A}; /* mag01[x] = x * MATRIX_A for x=0,1 */ if (mti >= N) { /* generate N words at one time */ int kk; if (mti == N+1) /* if sgenrand() has not been called, */ sgenrand(4357); /* a default initial seed is used */ for (kk=0;kk<N-M;kk++) { y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK); mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1]; } for (;kk<N-1;kk++) { y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK); mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1]; } y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK); mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1]; mti = 0; } y = mt[mti++]; y ^= TEMPERING_SHIFT_U(y); y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B; y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C; y ^= TEMPERING_SHIFT_L(y); return y; } /* this main() outputs first 1000 generated numbers */ main() { int j; sgenrand(4357); /* any nonzero integer can be used as a seed */ for (j=0; j<1000; j++) { printf("%12u ", genrand()); if (j%8==7) printf("\n"); } printf("\n"); }