mt19937ar.h File Reference

Go to the source code of this file.

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

Function Documentation

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 */
    }
}