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HPL_rand(3)                  HPL Library Functions                 HPL_rand(3)

NAME
       HPL_rand - random number generator.

SYNOPSIS
       #include "hpl.h"

       double HPL_rand();

DESCRIPTION
       HPL_rand generates  the next number  in the  random  sequence.  This
       function  ensures  that this number lies in the interval (-0.5, 0.5].

       The static array irand contains the information (2 integers) required
       to generate the  next number  in the sequence  X(n).  This  number is
       computed as X(n) = (2^32 * irand[1] + irand[0]) / d - 0.5,  where the
       constant d is the largest 64 bit positive integer. The array irand is
       then  updated  for the generation of the next number  X(n+1)  in  the
       random sequence as follows X(n+1) = a * X(n) + c. The constants a and c
       should have been preliminarily stored in the arrays ias and ics as 2
       pairs of integers.  The initialization of  ias,  ics and  irand  is
       performed by the function HPL_setran.

SEE ALSO
       HPL_ladd (3), HPL_lmul (3), HPL_setran (3), HPL_xjumpm (3),
       HPL_jumpit (3).

HPL 2.1                        October 26, 2012                    HPL_rand(3)