Nathan Letwory
145 lines
5.0 KiB
C++
145 lines
5.0 KiB
C++
/*
|
|
* $Id$
|
|
* ***** BEGIN GPL LICENSE BLOCK *****
|
|
*
|
|
* 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.
|
|
*
|
|
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
|
|
* All rights reserved.
|
|
*
|
|
* The Original Code is: all of this file.
|
|
*
|
|
* Contributor(s): none yet.
|
|
*
|
|
* ***** END GPL LICENSE BLOCK *****
|
|
*/
|
|
|
|
/** \file moto/intern/MT_random.cpp
|
|
* \ingroup moto
|
|
*/
|
|
|
|
|
|
/* A C-program for MT19937: Real number version */
|
|
|
|
/* genrand() generates one pseudorandom real number (double) */
|
|
/* which is uniformly distributed on [0,1]-interval, 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). */
|
|
/* Integer generator is obtained by modifying two lines. */
|
|
/* 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., 51 Franklin Street, Fifth Floor, Boston, MA */
|
|
/* 02110-1301, USA */
|
|
|
|
/* Copyright (C) 1997 Makoto Matsumoto and Takuji Nishimura. */
|
|
/* When you use this, send an email to: matumoto@math.keio.ac.jp */
|
|
/* with an appropriate reference to your work. */
|
|
|
|
#include "MT_random.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 int 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 MT_srand(unsigned int 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 int MT_rand()
|
|
{
|
|
static unsigned int mag01[2] = { 0x0, MATRIX_A };
|
|
/* mag01[x] = x * MATRIX_A for x=0,1 */
|
|
|
|
unsigned int y;
|
|
|
|
if (mti >= N) { /* generate N words at one time */
|
|
int kk;
|
|
|
|
if (mti == N+1) /* if sgenrand() has not been called, */
|
|
MT_srand(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;
|
|
}
|
|
|
|
#undef N
|
|
#undef M
|
|
#undef MATRIX_A
|
|
#undef UPPER_MASK
|
|
#undef LOWER_MASK
|
|
|
|
/* Tempering parameters */
|
|
#undef TEMPERING_MASK_B
|
|
#undef TEMPERING_MASK_C
|
|
#undef TEMPERING_SHIFT_U
|
|
#undef TEMPERING_SHIFT_S
|
|
#undef TEMPERING_SHIFT_T
|
|
#undef TEMPERING_SHIFT_L
|
|
|