mt19937ar.cpp File Reference

#include <stdio.h>

Go to the source code of this file.

Macros
#define	N   624
#define	M   397
#define	MATRIX_A   0x9908b0dfUL /* constant vector a */
#define	UPPER_MASK   0x80000000UL /* most significant w-r bits */
#define	LOWER_MASK   0x7fffffffUL /* least significant r bits */

Functions
void	init_genrand (unsigned long s)
void	init_by_array (unsigned long init_key[], int key_length)
unsigned long	genrand_int32 (void)
long	genrand_int31 (void)
double	genrand_real1 (void)
double	genrand_real2 (void)
double	genrand_real3 (void)
double	genrand_res53 (void)

Variables
static unsigned long	mt [N]
static int	mti =N+1

Macro Definition Documentation

LOWER_MASK

#define LOWER_MASK   0x7fffffffUL /* least significant r bits */

Definition at line 51 of file mt19937ar.cpp.

Referenced by genrand_int32().

M

#define M   397

Definition at line 48 of file mt19937ar.cpp.

Referenced by genrand_int32().

MATRIX_A

#define MATRIX_A   0x9908b0dfUL /* constant vector a */

Definition at line 49 of file mt19937ar.cpp.

Referenced by genrand_int32().

N

#define N   624

Definition at line 47 of file mt19937ar.cpp.

Referenced by genrand_int32(), init_by_array(), and init_genrand().

UPPER_MASK

#define UPPER_MASK   0x80000000UL /* most significant w-r bits */

Definition at line 50 of file mt19937ar.cpp.

Referenced by genrand_int32().

Function Documentation

genrand_int31()

long genrand_int31

(

void

)

Definition at line 140 of file mt19937ar.cpp.

References genrand_int32().

{
    return (long)(genrand_int32()>>1);
}

genrand_int32()

unsigned long genrand_int32

(

void

)

Definition at line 102 of file mt19937ar.cpp.

References init_genrand(), LOWER_MASK, M, MATRIX_A, mt, mti, N, and UPPER_MASK.

Referenced by genrand_int31(), genrand_real1(), genrand_real2(), genrand_real3(), and genrand_res53().

{
    unsigned long y;
    static unsigned long mag01[2]={0x0UL, 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 init_genrand() has not been called, */
            init_genrand(5489UL); /* 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 & 0x1UL];
        }
        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 & 0x1UL];
        }
        y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
        mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL];

        mti = 0;
    }
  
    y = mt[mti++];

    /* Tempering */
    y ^= (y >> 11);
    y ^= (y << 7) & 0x9d2c5680UL;
    y ^= (y << 15) & 0xefc60000UL;
    y ^= (y >> 18);

    return y;
}

genrand_real1()

double genrand_real1

(

void

)

Definition at line 146 of file mt19937ar.cpp.

References genrand_int32().

{
    return genrand_int32()*(1.0/4294967295.0); 
    /* divided by 2^32-1 */ 
}

genrand_real2()

double genrand_real2

(

void

)

Definition at line 153 of file mt19937ar.cpp.

References genrand_int32().

{
    return genrand_int32()*(1.0/4294967296.0); 
    /* divided by 2^32 */
}

genrand_real3()

double genrand_real3

(

void

)

Definition at line 160 of file mt19937ar.cpp.

References genrand_int32().

{
    return (((double)genrand_int32()) + 0.5)*(1.0/4294967296.0); 
    /* divided by 2^32 */
}

genrand_res53()

double genrand_res53

(

void

)

Definition at line 167 of file mt19937ar.cpp.

References genrand_int32().

{ 
    unsigned long a=genrand_int32()>>5, b=genrand_int32()>>6; 
    return(a*67108864.0+b)*(1.0/9007199254740992.0); 
} 

init_by_array()

void init_by_array	(	unsigned long	init_key[],
		int	key_length
	)

Definition at line 76 of file mt19937ar.cpp.

References init_genrand(), mt, and N.

Referenced by QuESTSeedRandom(), and QuESTSeedRandomDefault().

{
    int i, j, k;
    init_genrand(19650218UL);
    i=1; j=0;
    k = (N>key_length ? N : key_length);
    for (; k; k--) {
        mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL))
          + init_key[j] + j; /* non linear */
        mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
        i++; j++;
        if (i>=N) { mt[0] = mt[N-1]; i=1; }
        if (j>=key_length) j=0;
    }
    for (k=N-1; k; k--) {
        mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL))
          - i; /* non linear */
        mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
        i++;
        if (i>=N) { mt[0] = mt[N-1]; i=1; }
    }

    mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */ 
}

init_genrand()

void init_genrand

(

unsigned long

s

)

Definition at line 57 of file mt19937ar.cpp.

References mt, mti, and N.

Referenced by genrand_int32(), and init_by_array().

{
    mt[0]= s & 0xffffffffUL;
    for (mti=1; mti<N; mti++) {
        mt[mti] = 
            (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti); 
        /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
        /* In the previous versions, MSBs of the seed affect   */
        /* only MSBs of the array mt[].                        */
        /* 2002/01/09 modified by Makoto Matsumoto             */
        mt[mti] &= 0xffffffffUL;
        /* for >32 bit machines */
    }
}

Variable Documentation

mt

unsigned long mt[N]

static

Definition at line 53 of file mt19937ar.cpp.

Referenced by genrand_int32(), init_by_array(), and init_genrand().

mti

int mti =N+1

static

Definition at line 54 of file mt19937ar.cpp.

Referenced by genrand_int32(), and init_genrand().