dms2dd Re: Expanding list into string within a command

[Jean Louis <bugs@gnu.support>]

I have actually forgot that I have already transitioned Common Lisp to
Emacs Lisp to convert DMS to DD coordinates.

(defun geo/dms-parse (dms)
  (let* ((cardinal (cond ((string-match "N" dms) "N")
			 ((string-match "S" dms) "S")
			 ((string-match "E" dms) "E")
			 ((string-match "W" dms) "W")
			 (t (error "No cardinal direction found"))))
	 (parts (string-replace-non-digits-for-spaces dms))
	 (parts (string-trim parts))
	 (parts (string-replace-shorten-spaces parts))
	 (parts (split-string parts))
	 (degrees (string-to-number (car parts)))
	 (minutes (string-to-number (cadr parts)))
	 (seconds (string-to-number (caddr parts))))
    (list degrees minutes seconds cardinal)))

(defun geo/dms2dd-degrees (d)
  (truncate d))

(defun geo/dms2dd-minutes (m)
  (float (/ m 60.0)))

(defun geo/dms2dd-seconds (s)
  (float (/ s 3600.0)))

(defun geo/dms2dd (dms)
  "Converts DMS value to DD geo value"
  (let* ((dms (geo/dms-parse dms))
	 (degrees (car dms))
	 (minutes (cadr dms))
	 (seconds (caddr dms))
	 (cardinal (cadddr dms))
	 (dd (+ (geo/dms2dd-degrees degrees)
		(geo/dms2dd-minutes minutes)
		(geo/dms2dd-seconds seconds))))
    (cond ((string= "S" cardinal) (- dd))
	  ((string= "W" cardinal) (- dd))
	  (t dd))))