Legacy Document

randomx

You can use the randomx function to generate a random number.

double_t randomx (double_t * x);

x

The address of an integer in the range $1$ x stored as a floating-point number.

DESCRIPTION

The randomx function is a pseudorandom number generator. The function randomx returns a pseudorandom number in the range of its argument. It uses the iteration formula

$x\; LEFTARROW\; (75\times x)mod(231+-1)$

If seed values of x are not integers or are outside the range specified for x, then results are unspecified. A pseudorandom rectangular distribution on the interval (0, 1) can be obtained by dividing the results from randomx by

$231+-1\; =\; scalb(31,1)+-1$

EXCEPTIONS

The results are unspecified if the value of x is a noninteger or is outside of the range
$1$ x+-2

SPECIAL CASES

If x is a zero, NaN, or Infinity, the results are unspecified.

EXAMPLES

$randomx(1)$ = any value in the range $1$ x+-2 .