nag_rngs_logical (g05kec) (PDF version)
g05 Chapter Contents
g05 Chapter Introduction
NAG C Library Manual

NAG Library Function Document

nag_rngs_logical (g05kec)

+ Contents

    1  Purpose
    7  Accuracy

1  Purpose

nag_rngs_logical (g05kec) returns a pseudorandom logical value – true with probability p and false with probability 1-p.

2  Specification

#include <nag.h>
#include <nagg05.h>
Nag_Boolean  nag_rngs_logical (double p, Integer igen, Integer iseed[], NagError *fail)

3  Description

nag_rngs_logical (g05kec) returns the logical value of the relation
y<p
where y is a pseudorandom number from a uniform distribution over 0,1, generated by nag_rngs_basic (g05kac) using the values of igen and iseed as input to this function.
One of the initialization functions nag_rngs_init_repeatable (g05kbc) (for a repeatable sequence if computed sequentially) or nag_rngs_init_nonrepeatable (g05kcc) (for a non-repeatable sequence) must be called prior to the first call to nag_rngs_logical (g05kec).

4  References

Knuth D E (1981) The Art of Computer Programming (Volume 2) (2nd Edition) Addison–Wesley

5  Arguments

1:     pdoubleInput
On entry: must contain the probability of nag_rngs_logical (g05kec) returning Nag_TRUE.
Constraint: 0.0p1.0.
2:     igenIntegerInput
On entry: must contain the identification number for the generator to be used to return a pseudorandom number and should remain unchanged following initialization by a prior call to nag_rngs_init_repeatable (g05kbc) or nag_rngs_init_nonrepeatable (g05kcc).
3:     iseed[4]IntegerCommunication Array
On entry: contains values which define the current state of the selected generator.
On exit: contains updated values defining the new state of the selected generator.
4:     failNagError *Input/Output
The NAG error argument (see Section 3.6 in the Essential Introduction).

6  Error Indicators and Warnings

NE_BAD_PARAM
On entry, argument value had an illegal value.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
NE_REAL
On entry, p<0.0 or p>1.0: p=value.

7  Accuracy

Not applicable.

8  Further Comments

None.

9  Example

This example prints the first five pseudorandom logical values generated by nag_rngs_logical (g05kec) after initialization by nag_rngs_init_repeatable (g05kbc), when the probability of a TRUE value is 0.6.

9.1  Program Text

Program Text (g05kece.c)

9.2  Program Data

None.

9.3  Program Results

Program Results (g05kece.r)


nag_rngs_logical (g05kec) (PDF version)
g05 Chapter Contents
g05 Chapter Introduction
NAG C Library Manual

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