C     This program prompts the user for the name of a data file which
C     contains coordinates for points in a Cartesian plane.  The program
C     reads all the points in the file and then prints average distance
C     of the points from the origin as well as the total number
C     of points read from the file.
C
C     The points are only specified with four digits of precision and
C     are all less than ten units away from the origin.  The data is
C     stored without the decimal point and there isn't necessarily a
C     space between the numbers so that the data can be correctly read
C     with a 2F5.3 format descriptor.
C     
C     John Schneider
C     CptS 203, HW 5, problem 2
C--------------------------------------------------------------------------
      program dstavg
      implicit none

      real x, y, sum
      integer count
      character filnam*50

      count = 0
      sum   = 0.0

      print *, 'Enter the input file name.'
      read '(a)', filnam

      open(unit=27,file=filnam,status='old')
      
 10   continue
         read(27,'(2f5.3)',end=20)x,y
         sum = sum + sqrt(x*x + y*y)
         count = count + 1
      goto 10
 20   continue

      print *, 'There were ',count,' entries in the file.'
      print *, 'The average distance is ',sum/count,'.'

      stop
      end