anchor.diff:  ;; Unit conversions, etc.
   ;;
   ;;  1 knot = 1.852000 km/hr*
  -;;  1 knot = 185200/109728 ft/sec* =1.687810 ft/sec
  +;;  1 knot = 185200/109728 ft/sec* = 1.687810 ft/sec
   ;;  1 knot = 1852000/1609344 mph* = 1.150779 mph
   ;;  1 mph  = 0.868976 knot
   ;;  1 mph  = 1.609344 km/hr*
  
positive.code:   ())
  
  (defmethod maidenhead ((p 2d-point))
    "Derived from WA5ZNU's code at http://wa5znu.org/log/2004/04/qra-maidenhead-grid-in-emacs-lisp.html"
    (let ((lat (point-lat p)) (lon (point-lon p)))
      (setf lon (+ lon 180.0))
      (setf lat (+ lat 90.0))
  
negative.code: that type."
    (mapcar #'(lambda (n)
  	      (cond
  		((equal (first n) 'serial-number)
  		 (setf (point-serial-number p) (second n)))
  		((equal (first n) 'creation-time)
  		 (setf (point-creation-time p) (second n)))
  		((equal (first n) 'creation-source)
  		 (setf (point-creation-source p) (second n)))
  		((equal (first n) 'name)
  		 (setf (point-name p) (second n)))
  		((equal (first n) 'description)
  		 (setf (point-description p) (second n)))
  		))
  	  point-data)
    )
  
  