From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Alexis Newsgroups: gmane.emacs.bugs Subject: bug#19025: 24.4; precision error when adding two floats Date: Wed, 12 Nov 2014 12:38:12 +1100 Message-ID: <87oasd6vl4.fsf@gmail.com> References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1415756791 14475 80.91.229.3 (12 Nov 2014 01:46:31 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 12 Nov 2014 01:46:31 +0000 (UTC) To: 19025@debbugs.gnu.org Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Wed Nov 12 02:46:24 2014 Return-path: Envelope-to: geb-bug-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 1XoN0q-0000Z7-2X for geb-bug-gnu-emacs@m.gmane.org; Wed, 12 Nov 2014 02:46:24 +0100 Original-Received: from localhost ([::1]:51997 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoN0p-0007uW-Jg for geb-bug-gnu-emacs@m.gmane.org; Tue, 11 Nov 2014 20:46:23 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:54347) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoN0d-0007uA-Nv for bug-gnu-emacs@gnu.org; Tue, 11 Nov 2014 20:46:20 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XoN0U-00030i-NB for bug-gnu-emacs@gnu.org; Tue, 11 Nov 2014 20:46:11 -0500 Original-Received: from debbugs.gnu.org ([140.186.70.43]:60756) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoN0U-00030a-KU for bug-gnu-emacs@gnu.org; Tue, 11 Nov 2014 20:46:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1XoN0U-0004La-7z for bug-gnu-emacs@gnu.org; Tue, 11 Nov 2014 20:46:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Alexis Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 12 Nov 2014 01:46:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 19025 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: X-Debbugs-Original-To: bug-gnu-emacs@gnu.org Original-Received: via spool by submit@debbugs.gnu.org id=B.141575673516671 (code B ref -1); Wed, 12 Nov 2014 01:46:02 +0000 Original-Received: (at submit) by debbugs.gnu.org; 12 Nov 2014 01:45:35 +0000 Original-Received: from localhost ([127.0.0.1]:57969 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XoN02-0004Ko-7R for submit@debbugs.gnu.org; Tue, 11 Nov 2014 20:45:35 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:52366) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XoMzz-0004Kf-I6 for submit@debbugs.gnu.org; Tue, 11 Nov 2014 20:45:32 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XoMzq-0002sh-0T for submit@debbugs.gnu.org; Tue, 11 Nov 2014 20:45:31 -0500 Original-Received: from lists.gnu.org ([2001:4830:134:3::11]:36121) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoMzp-0002sZ-Tr for submit@debbugs.gnu.org; Tue, 11 Nov 2014 20:45:21 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:54013) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoMzg-0007rO-TE for bug-gnu-emacs@gnu.org; Tue, 11 Nov 2014 20:45:21 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XoMzX-0002c4-TL for bug-gnu-emacs@gnu.org; Tue, 11 Nov 2014 20:45:12 -0500 Original-Received: from mail-pd0-x231.google.com ([2607:f8b0:400e:c02::231]:47422) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoMzX-0002Z0-Mv for bug-gnu-emacs@gnu.org; Tue, 11 Nov 2014 20:45:03 -0500 Original-Received: by mail-pd0-f177.google.com with SMTP id v10so11104130pde.22 for ; Tue, 11 Nov 2014 17:45:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=references:from:to:subject:date:in-reply-to:message-id:mime-version :content-type; bh=4aLMmOCUQCPwV40TelK+lOLj9MVhbxJexrL64rEMuWU=; b=TzHjQe7lX62J4OVCZMaOeBbwiSdjRsgyIiGTleCfFqqm0/+i57EGaWm3SfYw+vzbAT fuXqTwJQ6l7KSIeFkNGt/yX4JF3ISmggLN+n7rNT8SmqldZXX80YGlsy3g8qH/amHCEV Tz2TFyr9f//AewFjvOHPI+E31SZtqkHjc2QpR291qykYmH6NSdHuAp5f3nsmMpztlaVa TkM2IinpNe3XxDqoHONJdxyEIIl1v8iVKqkAzi2bB7zV6NURTx7aQG1YeqlaOC4bjP+s LmixH0aCQaRuVgzGZsxQg3IhJu/2Nx3YIp2hx0LDVT9LZ1IjgrTIouCJDAZeD1dH1c5U rRfw== X-Received: by 10.70.118.165 with SMTP id kn5mr15655280pdb.140.1415756702187; Tue, 11 Nov 2014 17:45:02 -0800 (PST) Original-Received: from localhost (ppp118-209-92-67.lns20.mel4.internode.on.net. [118.209.92.67]) by mx.google.com with ESMTPSA id rz6sm20432179pbc.74.2014.11.11.17.45.00 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Tue, 11 Nov 2014 17:45:01 -0800 (PST) In-reply-to: X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:95888 Kevin W. Currey writes: > (message "%s" (+ 379.744 57.93)) > > The above prints 437.67400000000004. Same if I use 57.930, but if I use 57.931 (below) I get the correct answer 437.675. > > (message "%s" (+ 379.744 57.931)) > > I was able to work around by using format: > > (message "%s" (format "%f" (+ 379.744 57.93))) > > which prints 437.674000. > > FYI, I can replicate the issue with Emacs 21.3.1. Isn't this an artifact of the nature of floating-point arithmetic, rather than an issue with Emacs per se? For example, in Python: Python 2.7.3 (default, Mar 13 2014, 11:03:55) [GCC 4.7.2] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> 379.744 + 57.93 437.67400000000004 >>> Alexis.