Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 6/24/2024
Public

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vRngUniformBits

Generates bits of underlying BRNG integer recurrence.

Syntax

status = virnguniformbits( method, stream, n, r )

Include Files

  • mkl.fi, mkl_vsl.f90

Input Parameters

Name

Type

Description

method

INTEGER, INTENT(IN)

Generation method; the specific value is

VSL_RNG_METHOD_UNIFORMBITS_STD

stream

TYPE (VSL_STREAM_STATE), INTENT(IN)

Descriptor of the stream state structure.

n

INTEGER, INTENT(IN)

Number of random values to be generated

Output Parameters

Name

Type

Description

r

INTEGER(KIND=4), INTENT(OUT)

Vector of n random integer numbers. If the stream was generated by a 64 or a 128-bit generator, each integer value is represented by two or four elements of r respectively. The number of bytes occupied by each integer is contained in the field wordsize of the structure VSL_BRNG_PROPERTIES. The total number of bits that are actually used to store the value are contained in the field nbits of the same structure. See Advanced Service Routines for a more detailed discussion of VSLBRngProperties.

Description

The vRngUniformBits function generates integer random values with uniform bit distribution. The generators of uniformly distributed numbers can be represented as recurrence relations over integer values in modular arithmetic. Apparently, each integer can be treated as a vector of several bits. In a truly random generator, these bits are random, while in pseudorandom generators this randomness can be violated. For example, a well known drawback of linear congruential generators is that lower bits are less random than higher bits (for example, see [Knuth81]). For this reason, care should be taken when using this function. Typically, in a 32-bit LCG only 24 higher bits of an integer value can be considered random. See VS Notes for details.

Product and Performance Information

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.

Notice revision #20201201

Return Values

VSL_ERROR_OK, VSL_STATUS_OK

Indicates no error, execution is successful.

VSL_ERROR_NULL_PTR

stream is a NULL pointer.

VSL_RNG_ERROR_BAD_STREAM

stream is not a valid random stream.

VSL_RNG_ERROR_BAD_UPDATE

Callback function for an abstract BRNG returns an invalid number of updated entries in a buffer, that is, < 0 or > nmax.

VSL_RNG_ERROR_NO_NUMBERS

Callback function for an abstract BRNG returns 0 as the number of updated entries in a buffer.

VSL_RNG_ERROR_QRNG_PERIOD_ELAPSED

Period of the generator has been exceeded.

VSL_RNG_ERROR_NONDETERM_NRETRIES_EXCEEDED

Number of retries to generate a random number by using non-deterministic random number generator exceeds threshold.

VSL_RNG_ERROR_ARS5_NOT_SUPPORTED

ARS-5 random number generator is not supported on the CPU running the application.