nag_rngs_init_nonrepeatable (g05kcc) (PDF version)
g05 Chapter Contents
g05 Chapter Introduction
NAG C Library Manual

NAG Library Function Document

nag_rngs_init_nonrepeatable (g05kcc)

+ Contents

    1  Purpose
    7  Accuracy

1  Purpose

nag_rngs_init_nonrepeatable (g05kcc) sets the seeds to a non-repeatable initial value for the selected generator as used by and passed to the group of pseudorandom number functions g05k–g05q.

2  Specification

#include <nag.h>
#include <nagg05.h>
void  nag_rngs_init_nonrepeatable (Integer *igen, Integer iseed[])

3  Description

nag_rngs_init_nonrepeatable (g05kcc) sets the seeds used by the selected generator mechanism (see the g05 Chapter Introduction) to values calculated from the setting of the real-time clock. The pseudorandom number generator is selected by the input value of the argument igen.
This function will yield different subsequent sequences of random numbers in different runs of the calling program. It should be noted that there is no guarantee of statistical properties between sequences, only within sequences.

4  References

None.

5  Arguments

1:     igenInteger *Input/Output
On entry: must contain the identification number for the generator to be used to return a pseudorandom number and should remain unchanged until a re-initialization by a call to one of the functions nag_rngs_init_repeatable (g05kbc) or nag_rngs_init_nonrepeatable (g05kcc). The values that may be chosen are:
  • igen=0, the basic generator;
  • 1igen273, a Wichman–Hill generator.
See the g05 Chapter Introduction for details.
On exit: if igen<0 on input then igen is set to 0, if igen>273 on input then igen is set to igen-1 mod 273+1.
2:     iseed[4]IntegerCommunication Array
On exit: contains values which define an initial state for the generator selected by the argument igen. The values returned will differ for each run of the calling program.

6  Error Indicators and Warnings

None.

7  Accuracy

Not applicable.

8  Further Comments

None.

9  Example

This example prints the first five pseudorandom real numbers from a uniform distribution between 0 and 1, generated by nag_rngs_basic (g05kac) after initialization by nag_rngs_init_nonrepeatable (g05kcc).

9.1  Program Text

Program Text (g05kcce.c)

9.2  Program Data

None.

9.3  Program Results

Program Results (g05kcce.r)


nag_rngs_init_nonrepeatable (g05kcc) (PDF version)
g05 Chapter Contents
g05 Chapter Introduction
NAG C Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2012