PRO readxy, file, x, y

; Read a 1d function from a free-format 2-column file

  x=FltArr(500000)
  y=FltArr(500000)

  openr,lun,file,/get_lun

  i=0L & valid = 0
  WHILE valid EQ 0 DO BEGIN
    ON_IOERROR, end_of_file
    ReadF, lun, xx,yy
    x(i)=xx &  y(i)=yy 
    i = i + 1L
  ENDWHILE

  end_of_file:
  Close,lun
  Free_lun, lun

  x=x(0:i-1) & y=y(0:i-1) 

END