program prog09
c This program analyzes the distribution of random numbers [0,1)
c generated by
c     function rnd
c
      implicit real*8(a-h,o-z)
      integer*4 iseed
c dimension = vector
      dimension hist(50)
c Initialization
      iseed = 123456789
      n = 100000
      dx = 1.0d0/50
      do j = 1,50
         hist(j) = 0.0d0
      end do
c Make Histograms
      do i = 1,n
         x = rnd(iseed)
         j = int(x/dx)+1
         hist(j) = hist(j) + 1.0d0
      end do
c Output
      do j = 1,50
         write(*,100) dx*(j-0.5d0),hist(j)/n/dx
      end do
 100  format(2(1x,f10.4))
      end
c **********************************************************************
      function rnd(iseed)
c **********************************************************************
      implicit real*8(a-h,o-z)
c...32 bit (=4byte) machine
      integer*4 iseed,il,ic,ih
      il = 843314861
      ic = 453816693
      ih = 2**30
      xmax = 2.0d0**31
c
      iseed = iseed*il + ic
      if(iseed.lt.0) iseed = (iseed + ih) + ih
      rnd = iseed/xmax
c
      end