From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Newsgroups: gmane.emacs.bugs Subject: bug#41223: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables Date: Thu, 14 May 2020 10:43:19 +0200 Message-ID: <7A33094E-BD4C-45DE-A57D-F23D50CFC6B4@acm.org> References: Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.14\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="56507"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 41223-done@debbugs.gnu.org To: Mauro Aranda Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Thu May 14 10:44:30 2020 Return-path: Envelope-to: geb-bug-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 1jZ9Th-000EZj-RD for geb-bug-gnu-emacs@m.gmane-mx.org; Thu, 14 May 2020 10:44:29 +0200 Original-Received: from localhost ([::1]:42072 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jZ9Tg-0000jK-Rd for geb-bug-gnu-emacs@m.gmane-mx.org; Thu, 14 May 2020 04:44:28 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:53908) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jZ9TI-0000Vf-5V for bug-gnu-emacs@gnu.org; Thu, 14 May 2020 04:44:04 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:48632) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jZ9TG-0004H3-Jb for bug-gnu-emacs@gnu.org; Thu, 14 May 2020 04:44:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jZ9TG-0006u0-IK for bug-gnu-emacs@gnu.org; Thu, 14 May 2020 04:44:02 -0400 Resent-From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Original-Sender: "Debbugs-submit" Resent-To: bug-gnu-emacs@gnu.org Resent-Date: Thu, 14 May 2020 08:44:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: cc-closed 41223 X-GNU-PR-Package: emacs Mail-Followup-To: 41223@debbugs.gnu.org, mattiase@acm.org, maurooaranda@gmail.com Original-Received: via spool by 41223-done@debbugs.gnu.org id=D41223.158944582126459 (code D ref 41223); Thu, 14 May 2020 08:44:02 +0000 Original-Received: (at 41223-done) by debbugs.gnu.org; 14 May 2020 08:43:41 +0000 Original-Received: from localhost ([127.0.0.1]:60174 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jZ9Sg-0006sO-NS for submit@debbugs.gnu.org; Thu, 14 May 2020 04:43:41 -0400 Original-Received: from mail154c50.megamailservers.eu ([91.136.10.164]:43094 helo=mail50c50.megamailservers.eu) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jZ9Se-0006sE-Uy for 41223-done@debbugs.gnu.org; Thu, 14 May 2020 04:43:26 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1589445802; bh=fb4M/RJByZP5xPJPv3pR9y0nRu2/SKu0Iop1ADsaRFI=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=U9hTlx7MjP+qOjqxeW1W9rKlvup7WALvs0EzauQXT9jzjY93P1+aAKk4D8xrlSPPR Z7TKxdF4SYVHwnoeZNIHUKVp+if5JCdY6chVP2QGveym2i0y7bq0gjnzofZ2uZgVs3 sJBtkx+XkPLIwoguV2CkXnzviQlgsoVdZI1ufDkg= Feedback-ID: mattiase@acm.or Original-Received: from stanniol.lan (c-4e4ae655.032-75-73746f71.bbcust.telenor.se [85.230.74.78]) (authenticated bits=0) by mail50c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id 04E8hKFp025286; Thu, 14 May 2020 08:43:21 +0000 In-Reply-To: X-Mailer: Apple Mail (2.3445.104.14) X-CTCH-RefID: str=0001.0A782F1C.5EBD0474.005A, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0 X-CTCH-VOD: Unknown X-CTCH-Spam: Unknown X-CTCH-Score: 0.000 X-CTCH-Flags: 0 X-CTCH-ScoreCust: 0.000 X-CSC: 0 X-CHA: v=2.3 cv=NoevjPVJ c=1 sm=1 tr=0 a=klNLuyVZdLUgl+K5Uafb2A==:117 a=klNLuyVZdLUgl+K5Uafb2A==:17 a=kj9zAlcOel0A:10 a=M51BFTxLslgA:10 a=pGLkceISAAAA:8 a=XS1haWe4n0UfRBynA64A:9 a=CjuIK1q_8ugA:10 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list 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-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:180195 Archived-At: 14 maj 2020 kl. 00.15 skrev Mauro Aranda : > It is good enough for me. Thanks. The pleasure was all mine! It has now been pushed to master. No doubt there are better ways of computing the determinant for = non-numeric matrices. In particular, division shouldn't be necessary at = all, and the current algorithm results in some untidy expressions. For = example, the determinant of [a 0 0 1] [0 b 0 0] [0 0 c 0] [1 0 0 d] is given as abc*(d-1/a), falsely giving the impression of being = undefined for a=3D0, rather than bc(ad-1).