From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: Floating Point computations in elisp Date: Fri, 18 Dec 2020 18:08:10 +0100 Message-ID: <87mtybyrd1.fsf@zoho.eu> References: Reply-To: Emanuel Berg Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="10108"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:XbYnmfdsmVTos4+RM2UCsWGMcCA= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Dec 18 18:08:56 2020 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kqJFQ-0002W4-34 for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 18 Dec 2020 18:08:56 +0100 Original-Received: from localhost ([::1]:60424 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kqJFP-0002K8-62 for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 18 Dec 2020 12:08:55 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:55894) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kqJEp-0002HW-Hh for help-gnu-emacs@gnu.org; Fri, 18 Dec 2020 12:08:19 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]:36164) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kqJEn-0006Te-TT for help-gnu-emacs@gnu.org; Fri, 18 Dec 2020 12:08:19 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1kqJEl-0001pR-QZ for help-gnu-emacs@gnu.org; Fri, 18 Dec 2020 18:08:15 +0100 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Mail-Copies-To: never Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 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-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:126510 Archived-At: > How can I do floating point computations in elisp > > (setq frc (/ tpd 60.0)) As you did, just add a .0 to avoid integer division. Other than that, just compute whatever you like. (defun mean-value (vs) (let*((sum (apply #'+ vs)) (mean (/ sum (length vs) 1.0)) ) mean) ) (defun hypotenuse (c1 c2) (sqrt (+ (* c1 c1) (* c2 c2))) ) (defun speed (hour minute second km) (let*((s (+ second (* 60 minute) (* 60 60 hour))) (m (* 1000 km)) (mps (/ m s)) ) (* 3.6 mps) )) Hm ... what does that do? Anyway, you can then use `format' to - that's right - format the output. It is very versatile, see the docstring. (defun compute-space-distance (dist num-beams beam-width) (let*((spaces (1+ num-beams)) (dist-covered (* num-beams beam-width)) (dist-uncovered (- dist dist-covered)) (space (/ dist-uncovered spaces 1.0) )) space )) ;; (insert (format "\n;; %.2f" (compute-space-distance 262 16 12))) ;; 4.12 -- underground experts united http://user.it.uu.se/~embe8573 https://dataswamp.org/~incal