From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Jean Louis Newsgroups: gmane.emacs.help Subject: Re: What is 0.01 here not 0.01 here 0.009999999999999? Date: Fri, 2 Apr 2021 21:44:40 +0300 Message-ID: References: <87eefsk2hq.fsf@iki.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="8638"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/2.0.6 (2021-03-06) Cc: help-gnu-emacs@gnu.org, Stefan Monnier To: Teemu Likonen Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Apr 02 20:48:47 2021 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 1lSOqd-000298-4s for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 02 Apr 2021 20:48:47 +0200 Original-Received: from localhost ([::1]:39846 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lSOqc-0005H2-26 for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 02 Apr 2021 14:48:46 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:35032) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lSOpo-0005Ew-2x for help-gnu-emacs@gnu.org; Fri, 02 Apr 2021 14:47:56 -0400 Original-Received: from stw1.rcdrun.com ([217.170.207.13]:41395) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lSOpl-0001En-VU for help-gnu-emacs@gnu.org; Fri, 02 Apr 2021 14:47:55 -0400 Original-Received: from localhost ([::ffff:41.202.241.42]) (AUTH: PLAIN securesender, TLS: TLS1.3,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 000000000001E1D1.00000000606766D6.00005EA4; Fri, 02 Apr 2021 11:47:49 -0700 Mail-Followup-To: Teemu Likonen , Stefan Monnier , help-gnu-emacs@gnu.org Content-Disposition: inline In-Reply-To: <87eefsk2hq.fsf@iki.fi> Received-SPF: pass client-ip=217.170.207.13; envelope-from=bugs@gnu.support; helo=stw1.rcdrun.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham 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:128818 Archived-At: * Teemu Likonen [2021-04-02 20:42]: > * 2021-04-02 20:03:54+0300, Jean Louis wrote: > > > Not that I need the absolute internally, just the practical > > result as we learned it in school like that 10.11 plus 0.01 > > results with 10.12 and not something else. Results are used for > > automated version numbers (in some cases). > > As you have learned, floating point numbers are not decimal numbers even > if they are read and printed as such. For decimal mathematics you can > use calc-eval function. Some comparison: > > ELISP> (+ 10.12 0.01) > 10.129999999999999 > > ELISP> (calc-eval "10.12 + 0.01") > "10.13" > > ELISP> (* 3 0.1) > 0.30000000000000004 > > ELISP> (calc-eval "3 * 0.1") > "0.3" Hey, that is good to know, it spares me efforts. -- Jean Take action in Free Software Foundation campaigns: https://www.fsf.org/campaigns Sign an open letter in support of Richard M. Stallman https://rms-support-letter.github.io/