muni and haversine distance

This commit is contained in:
Ivan Malison 2016-06-16 10:56:41 -07:00
parent e0253bf734
commit 2d802f7be5

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@ -415,6 +415,63 @@ Prefix alternatives is a macro that builds a function that selects one of a coll
(setq result (concat (file-name-as-directory result) dir)))
result))
#+END_SRC
** Haversine distance
#+BEGIN_SRC emacs-lisp
(defun imalison:sin2 (p)
(let ((sin-p (sin p)))
(* sin-p sin-p) ))
(defun imalison:haversine-distance
(left-lat-long right-lat-long &optional radius)
;; Default to earth radius in km
(unless radius (setq radius 6378.1))
(interactive)
(cl-destructuring-bind (left-lat left-long) left-lat-long
(cl-destructuring-bind (right-lat right-long) right-lat-long
(let ((l1 (degrees-to-radians left-lat))
(f1 (degrees-to-radians left-long))
(l2 (degrees-to-radians right-lat))
(f2 (degrees-to-radians right-long)) )
(* 2 radius
(asin
(sqrt
(+ (imalison:sin2 (/ (- f2 f1) 2))
(* (cos f2) (cos f1) (imalison:sin2 (/ (- l2 l1) 2))) ))))))))
#+END_SRC
** Muni
#+BEGIN_SRC emacs-lisp
(defun imalison:muni (line direction stop)
(s-trim
(shell-command-to-string
(format "muni predict %s %s %s" line direction stop))))
(defun imalison:closest-stop (location targets)
(let (minimizing (minimum 1.0e+INF))
(cl-loop for stop-info in targets
do (let* ((stop-lat-long (car stop-info))
(this-dist (imalison:haversine-distance location stop-lat-long)))
(when (< this-dist minimum)
(setq minimizing stop-info
minimum this-dist))))
minimizing))
(defvar-setq imalison:dolores-muni
'((37.761351 -122.428225) ("J" "inbound" "6213") "dolo"))
(defvar-setq imalison:van-ness-muni
'((37.775488 -122.418988) ("J" "outbound" "6996") "van ness"))
(defvar imalison:muni-infos
(list imalison:dolores-muni imalison:van-ness-muni))
(defun imalison:get-closest-muni-info ()
(interactive)
(let ((closest-stop
(imalison:closest-stop (imalison:get-lat-long) imalison:muni-infos)))
(apply 'imalison:muni (cadr closest-stop))))
(defun imalison:parse-muni-info (info-string)
(when (string-match "\\([[:digit:]]\\{1,3\\}\\) *minutes" info-string)
(match-string-no-properties 1 info-string)))
#+END_SRC
** Other
#+BEGIN_SRC emacs-lisp
(defun imalison:join-paths (&rest paths)