From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: distance from Easter Island to Chile Date: Sun, 20 Apr 2014 02:03:32 +0200 Organization: Aioe.org NNTP Server Message-ID: <87mwfguasr.fsf@nl106-137-194.student.uu.se> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1397952331 21277 80.91.229.3 (20 Apr 2014 00:05:31 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 20 Apr 2014 00:05:31 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sun Apr 20 02:05:22 2014 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WbfG5-0006qV-TN for geh-help-gnu-emacs@m.gmane.org; Sun, 20 Apr 2014 02:05:22 +0200 Original-Received: from localhost ([::1]:43891 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WbfG5-0008DI-2W for geh-help-gnu-emacs@m.gmane.org; Sat, 19 Apr 2014 20:05:21 -0400 Original-Path: usenet.stanford.edu!news.kjsl.com!feeder.erje.net!eu.feeder.erje.net!news.stack.nl!aioe.org!.POSTED!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 42 Original-NNTP-Posting-Host: VVbyYd/iFZoeWNmD9i++cQ.user.speranza.aioe.org Original-X-Complaints-To: abuse@aioe.org User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) X-Notice: Filtered by postfilter v. 0.8.2 Cancel-Lock: sha1:Kl/vnjJQ5ztsKUxIWzFsP+NDvMg= Mail-Copies-To: never Original-Xref: usenet.stanford.edu gnu.emacs.help:204979 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:97244 Archived-At: ;; As you know, the Easter Bunny isn't the kind of guy ;; to go on vacation, neglecting his duty. Instead, he ;; dropped me this interesting piece of Elisp to ;; calculate the distance between Earth locations, ;; based on the "Haversine formula". ;; ;; According to the program, the Easter Island (the ;; world's most desolate place) is 4301 kilometers from ;; the capital of Chile. I Googled that selfsame ;; distance, and the result makes me think the Easter ;; Bunny pulled of a successful implementation, though ;; no one, of course, should be above criticism. ;; ;; Enjoy! (defun sin2 (p) (let ((sin-p (sin p))) (* sin-p sin-p) )) (defun distance (l1-r f1-r l2-r f2-r) (interactive) (let ((l1 (degrees-to-radians l1-r)) (f1 (degrees-to-radians f1-r)) (l2 (degrees-to-radians l2-r)) (f2 (degrees-to-radians f2-r)) ) (* 2 6378.1 ; Earth's radius (asin (sqrt (+ (sin2 (/ (- f2 f1) 2)) (* (cos f2) (cos f1) (sin2 (/ (- l2 l1) 2))) )))))) (distance 33.45 ; Santiago 70.6667 27.1167 ; Easter Island 109.3667 ) ; should be 3757.41 [1] ;; [1] http://www.mapcrow.info/Distance_between_Santiago_CI_and_Easter_Island_CI.html -- underground experts united: http://user.it.uu.se/~embe8573