Data types

The Advanced Service routines refer to a structure defining the properties of the basic generator. This structure is described in Fortran 90 as follows: TYPE VSL_BRNG_PROPERTIES
INTEGER streamstatesize
INTEGER nseeds
INTEGER includeszero
INTEGER wordsize
INTEGER nbits
INTEGER nitstream
INTEGER sbrng
INTEGER dbrng
INTEGER ibrng
END TYPE VSL_BRNG_PROPERTIES

The C version is as follows: typedef struct _VSLBRngProperties {
int StreamStateSize;
int NSeeds;
int IncludesZero;
int WordSize;
int NBits;
InitStreamPtr InitStream;
sBRngPtr sBRng;
dBRngPtr dBRng;
iBRngPtr iBRng;
} VSLBRngProperties;

The following table provides brief descriptions of the fields engaged in the above structure:

Field Descriptions
Field	Short Description
Fortran: streamstatesize C: StreamStateSize	The size, in bytes, of the stream state structure for a given basic generator.
Fortran: nseeds C: NSeeds	The number of 32-bit initial conditions (seeds) necessary to initialize the stream state structure for a given basic generator.
Fortran: includeszero C: IncludesZero	Flag value indicating whether the generator can produce a random 0.
Fortran: wordsize C: WordSize	Machine word size, in bytes, used in integer-value computations. Possible values: 4, 8, and 16 for 32, 64, and 128-bit generators, respectively.
Fortran: nbits C: NBits	The number of bits required to represent a random value in integer arithmetic. Note that, for instance, 48-bit random values are stored to 64-bit (8 byte) memory locations. In this case, wordsize/WordSize is equal to `8` (number of bytes used to store the random value), while nbits/NBits contains the actual number of bits occupied by the value (in this example, `48`).
Fortran: initstream C: InitStream	Contains the pointer to the initialization routine of a given basic generator.
Fortran: sbrng C: sBRng	Contains the pointer to the basic generator of single precision real numbers uniformly distributed over the interval (`a,b`) (real in Fortran and float in C).
Fortran: dbrng C: dBRng	Contains the pointer to the basic generator of double precision real numbers uniformly distributed over the interval (`a,b`) (double PRECISION in Fortran and double in C).
Fortran: ibrng C: iBRng	Contains the pointer to the basic generator of integer numbers with uniform bit distribution¹ (INTEGER in Fortran and unsigned int in C).

¹A specific generator that permits operations over single bits and bit groups of random numbers.