forked from bartvdbraak/blender
0fbadc8eb7
added the following 3 lines to everything in the intern dir: #ifdef HAVE_CONFIG_H #include <config.h> #endif Kent -- mein@cs.umn.edu
135 lines
4.5 KiB
C
135 lines
4.5 KiB
C
/* A C-program for MT19937: Integer version (1999/10/28) */
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/* genrand() generates one pseudorandom unsigned integer (32bit) */
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/* which is uniformly distributed among 0 to 2^32-1 for each */
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/* call. sgenrand(seed) sets initial values to the working area */
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/* of 624 words. Before genrand(), sgenrand(seed) must be */
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/* called once. (seed is any 32-bit integer.) */
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/* Coded by Takuji Nishimura, considering the suggestions by */
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/* Topher Cooper and Marc Rieffel in July-Aug. 1997. */
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/* This library is free software under the Artistic license: */
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/* see the file COPYING distributed together with this code. */
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/* For the verification of the code, its output sequence file */
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/* mt19937int.out is attached (2001/4/2) */
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/* Copyright (C) 1997, 1999 Makoto Matsumoto and Takuji Nishimura. */
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/* Any feedback is very welcome. For any question, comments, */
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/* see http://www.math.keio.ac.jp/matumoto/emt.html or email */
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/* matumoto@math.keio.ac.jp */
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/* REFERENCE */
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/* M. Matsumoto and T. Nishimura, */
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/* "Mersenne Twister: A 623-Dimensionally Equidistributed Uniform */
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/* Pseudo-Random Number Generator", */
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/* ACM Transactions on Modeling and Computer Simulation, */
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/* Vol. 8, No. 1, January 1998, pp 3--30. */
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#include<stdio.h>
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include "mt19937int.h"
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/* Period parameters */
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#define N 624
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#define M 397
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#define MATRIX_A 0x9908b0df /* constant vector a */
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#define UPPER_MASK 0x80000000 /* most significant w-r bits */
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#define LOWER_MASK 0x7fffffff /* least significant r bits */
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/* Tempering parameters */
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#define TEMPERING_MASK_B 0x9d2c5680
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#define TEMPERING_MASK_C 0xefc60000
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#define TEMPERING_SHIFT_U(y) (y >> 11)
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#define TEMPERING_SHIFT_S(y) (y << 7)
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#define TEMPERING_SHIFT_T(y) (y << 15)
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#define TEMPERING_SHIFT_L(y) (y >> 18)
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static unsigned long mt[N]; /* the array for the state vector */
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static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */
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/* Initializing the array with a seed */
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void sgenrand(signed long seed)
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{
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int i;
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for (i=0;i<N;i++) {
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mt[i] = seed & 0xffff0000;
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seed = 69069 * seed + 1;
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mt[i] |= (seed & 0xffff0000) >> 16;
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seed = 69069 * seed + 1;
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}
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mti = N;
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}
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/* Initialization by "sgenrand()" is an example. Theoretically, */
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/* there are 2^19937-1 possible states as an intial state. */
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/* This function allows to choose any of 2^19937-1 ones. */
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/* Essential bits in "seed_array[]" is following 19937 bits: */
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/* (seed_array[0]&UPPER_MASK), seed_array[1], ..., seed_array[N-1]. */
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/* (seed_array[0]&LOWER_MASK) is discarded. */
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/* Theoretically, */
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/* (seed_array[0]&UPPER_MASK), seed_array[1], ..., seed_array[N-1] */
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/* can take any values except all zeros. */
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void lsgenrand(unsigned long *seed_array)
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/* the length of seed_array[] must be at least N */
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{
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int i;
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for (i=0;i<N;i++)
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mt[i] = seed_array[i];
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mti=N;
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}
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unsigned long genrand()
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{
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unsigned long y;
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static unsigned long mag01[2]={0x0, MATRIX_A};
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/* mag01[x] = x * MATRIX_A for x=0,1 */
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if (mti >= N) { /* generate N words at one time */
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int kk;
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if (mti == N+1) /* if sgenrand() has not been called, */
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sgenrand(4357); /* a default initial seed is used */
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for (kk=0;kk<N-M;kk++) {
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y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
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mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1];
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}
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for (;kk<N-1;kk++) {
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y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
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mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1];
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}
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y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
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mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1];
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mti = 0;
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}
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y = mt[mti++];
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y ^= TEMPERING_SHIFT_U(y);
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y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B;
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y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C;
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y ^= TEMPERING_SHIFT_L(y);
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return y;
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}
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/* This main() outputs first 1000 generated numbers. */
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/*
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main()
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{
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int i;
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sgenrand(4357);
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for (i=0; i<1000; i++) {
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printf("%10lu ", genrand());
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if (i%5==4) printf("\n");
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}
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}
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*/
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