program curve_generate
      character*20 myfilename

      write(*,*)'Name your file, please:'
      read(*,*)myfilename
      open(unit=10,file=myfilename)

      write(*,*)'How many points for the curve?'
      read(*,*)n

      write(10,*)n

      write(*,*)'The range of x: (please give starting point
     * and end point)'
      read(*,*)x_start,x_stop

      dx=( x_stop - x_start )/(n-1)

      do i=1,n
        x = x_start + (i-1)*dx
        y = sin(x)
        write(10,*)x,y
      end do

      write(*,*)'Data saved in file: ', myfilename
      end