Parameters

genid

Type: System..::..Int32

On entry: must contain the type of base generator to use.

$\mathbf{genid}=1$

NAG basic generator.

$\mathbf{genid}=2$

Wichmann Hill I generator.

$\mathbf{genid}=3$

Mersenne Twister.

$\mathbf{genid}=4$

Wichmann Hill II generator.

$\mathbf{genid}=5$

ACORN generator.

$\mathbf{genid}=6$

L'Ecuyer MRG32k3a generator.

See the G05 class for details of each of the base generators.

Constraint: $\mathbf{genid}=1$, $2$, $3$, $4$, $5$ or $6$.

subid

Type: System..::..Int32

On entry: if $\mathbf{genid}=2$, subid indicates which of the $273$ sub-generators to use. In this case, the $\left(\left(\left|\mathbf{subid}\right|+272\right) mod 273\right)+1$ sub-generator is used.

If $\mathbf{genid}=5$, subid indicates the values of $k$ and $p$ to use, where $k$ is the order of the generator, and $p$ controls the size of the modulus, $M$, with $M=2^{\left(p\times 30\right)}$. If $\mathbf{subid}<1$, the default values of $k=10$ and $p=2$ are used, otherwise values for $k$ and $p$ are calculated from the formula, $\mathbf{subid}=k+1000\left(p-1\right)$.

If $\mathbf{genid}=6$ and $\mathbf{subid}\mathrm{ mod }2=0$ the range of the generator is set to $\left(0,1\right]$, otherwise the range is set to $\left(0,1\right)$; in this case the sequence is identical to the implementation of MRG32k3a in TestU01 (see L'Ecuyer and Simard (2002)) for identical seeds.

For all other values of genid, subid is not referenced.

ifail

Type: System..::..Int32%

On exit: $\mathbf{ifail}=0$ or $-1$ unless the method detects an error or a warning has been flagged (see [Error Indicators and Warnings]).