program template implicit real*8 (a - h, o - z) character*132 input, output write (*, '(5x, a)') 'enter filespec of input file.' read (*, '(a)') input write (*, '(5x, a)') 'enter filespec of output file.' read (*, '(a)') output open (unit = 1, file = input, status = 'old') open (unit = 2, file = output, status = 'unknown') pi = 3.14159265358979d0 c = 2.99792458d10 h = 6.62606957d-27 ! CODATA 2010 an = 6.02214129d23 ! CODATA 2010 c2 = 1.4387770d0 ! CODATA 2010 r = 82.057361d0 ! CODATA 2010 derived rk = 1.3806488d-16 ! CODATA 2010 du = 2.6867805d16 ! CODATA 2010 derived i = 1 20 read (1, *, end = 30) x, y i = i + 1 go to 20 30 npoints = i - 1 close (unit = 1) close (unit = 2) end