Man Page ran.3f




NAME

     ran - return a random number between 0 and 1


SYNOPSIS

     real function ran (i)
     integer*4 i


DESCRIPTION

     Repeated calls to ran generate random numbers with a uniform
     distribution.


NOTES

     See lcrans(3m).

     The range includes 0.0 and excludes 1.0.  The algorithm is a
     multiplicative,  congruential  type,  general  random number
     generator.  In general, the value of i is  set  once  during
     execution  of  the  calling program.  The initial value of i
     should be a large odd integer.  Each call to ran returns the
     next random number in the sequence.

     To get a different sequence of random numbers each time  you
     run  the  calling  program, you must set the argument i to a
     different initial value for each run.

     Usage:
       real  r, ran
       integer*4 i
       i = ...
            ...
       r = ran(i)

     Example:
     demo% cat ran1.f
     * ran1.f         <-- Generate random numbers
          integer*4 i, n
          real r(10)
          i = 760013
          do n = 1, 10
               r(n) = ran ( i )
          end do
          write ( *, "( 5 f11.6 )" ) r
          end
     demo% f77 -silent ran1.f
     demo% a.out
        0.222058 0.299851 0.390777 0.607055 0.653188
        0.060174 0.149466 0.444353 0.002982 0.976519
     demo%


FILES

     libF77.a


SEE ALSO

     lcrans, addrans, and shufrans in the  Numerical  Computation
     Guide