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random(3f) [bsd man page]

RANDOM(3F)																RANDOM(3F)

NAME
random, drandm, irandm - better random number generator SYNOPSIS
function irandm (iflag) function random (iflag) double precision function drandm (iflag) DESCRIPTION
These functions use random(3) to generate sequences of random numbers, and should be used rather than the older functions described in man 3f rand. If iflag is non-zero, it is used as a new seed for the random number generator, and the first new random value is returned. Irandm returns positive integers in the range 0 through 2147483647 ( 2**31-1). Random and drandm return values in the range 0. through 1.0 by dividing the integer random number from random(3) by 2147483647 . FILES
/usr/lib/libF77.a SEE ALSO
random(3) 4.3 Berkeley Distribution May 15, 1985 RANDOM(3F)

Check Out this Related Man Page

rand(3C)																  rand(3C)

NAME
rand(), rand_r(), srand() - simple random-number generator SYNOPSIS
DESCRIPTION
uses a multiplicative, congruential, random-number generator with period 2^32 that returns successive pseudo-random numbers in the range from 0 to 2^15-1. can be called at any time to reset the random-number generator to a random starting point. The generator is initially seeded with a value of 1. returns a random number at the address pointed to by the randval parameter. The seed parameter can be set at any time to start the random- number generator at an arbitrary point. Note The spectral properties of leave a great deal to be desired. provides a much better, though more elaborate, random-number generator (see drand48(3C)). RETURN VALUE
If seed or randval is NULL, returns 0. Otherwise, returns a psuedo-random integer. EXAMPLES
The following: int x, y; srand(10); x = rand(); y = rand(); would produce the same results as: int x, y, s = 10; x=rand_r(&s); y=rand_r(&s); WARNINGS
Users of should note that rand_r() now conforms with POSIX.1c. The old prototype of is supported for compatibility with existing DCE applications only. SEE ALSO
drand48(3C), random(3M), thread_safety(5), random(7). STANDARDS CONFORMANCE
rand(3C)

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