HP MLIB User's Guide Vol. 2 7th Ed.

614 HP MLIB User’s Guide

RANV VAX-compatible random numbers

Notes CALL RANV (iseed, n, x) produces the same n pseudorandom numbers as

returned by n successive references to RAN(iseed).

CALL RANV (iseed, n, x) produces the same value of iseed that would have

resulted from the last of

n successive references to RAN(iseed).

Starting a sequence twice with the same value of iseed will produce the same

pseudorandom sequence.

You may have as many independent sequences going at a time as you desire by

having a different iseed for each one.

The subprograms treat iseed as an unsigned 32-bit quantity. To write it out for

later continuation of the same sequence, either use unformatted I/O statements

or write it out with an octal, unsigned integer, or hexadecimal format descriptor

of the form O11, SU,I10, or Z8, respectively.

Example Fill an array X that is 10 elements long with a sequence of pseudorandom

numbers using the vector subprogram RANV.

INTEGER*4 ISEED,N

REAL*4 X(10)

ISEED = 1234 ! STARTING SEED

N = 10

CALL RANV (ISEED,N,X)

This ﬁlls array X with the same sequence of pseudorandom numbers and also

returns the same ﬁnal value of ISEED, as the “Example” on page 611 for RAN.