From debbugs-submit-bounces@debbugs.gnu.org Tue May 12 19:25:02 2020 Received: (at submit) by debbugs.gnu.org; 12 May 2020 23:25:02 +0000 Received: from localhost ([127.0.0.1]:56850 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jYeGj-0005Ey-Go for submit@debbugs.gnu.org; Tue, 12 May 2020 19:25:02 -0400 Received: from lists.gnu.org ([209.51.188.17]:39014) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jYeGh-0005El-74 for submit@debbugs.gnu.org; Tue, 12 May 2020 19:24:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53624) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYeGh-00037B-1F for bug-gnu-emacs@gnu.org; Tue, 12 May 2020 19:24:59 -0400 Received: from mail-wm1-x32e.google.com ([2a00:1450:4864:20::32e]:38641) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jYeGe-0004wL-O9 for bug-gnu-emacs@gnu.org; Tue, 12 May 2020 19:24:58 -0400 Received: by mail-wm1-x32e.google.com with SMTP id g12so26074016wmh.3 for ; Tue, 12 May 2020 16:24:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=oyVQ98DWd/qkRgwED+s8RsISSmU3r3SV86YHnL+oVZA=; b=iLWLgZkvATfp3WPbUNo1gF7PlcU6IQw4RS48VWuQ6MqpUhEPNJBnnV9oSA8QKWs2Qw L+IV4w8SpycuZ1j0OfOZd7CaLRSvCzkovDDQ31zqFK7cRdOEWxG7f/YtIQSFnPAO+O55 VZBo5Zpdc2tNIwAz8USygV/nPbAvJriKHOW1igrb1Sma3Abw9pyPbARWSPIUzx4Ltrtz YrnlzbeJ5CrAv01Oc6P1l6d+f/UoptaK61CwoN5sevI2OC5Qh5HZ6L7mHFOEqJJsxXbh BJLC5VoiTpS/02twzhKUpEOo0vlyqEMPAUZAowlfjohHtYwdCA4IuIIebulkuXFOCSmG YbdA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=oyVQ98DWd/qkRgwED+s8RsISSmU3r3SV86YHnL+oVZA=; b=j6yxQ/IaKBcV7x5BXBqgfFP0dUJPDYmQI9Tw3W1mX6/pAQ0SbTOOO3YDCSTAVVnD9i 6nqgOybRuyCfWZ1CxBK4k9pom00NkVWqVQpQvbKRf0tNk/Z85WR3UChdJ13cfjogDW2v DWlHRwlB6uxe0heooD78LEXwuDrbIzNxKhEtTww9MSXhkRmkuQtDO/NUMLZl3ioogCeJ aPnazkUPetVF8qEsMrqnTld1tnohYoWjuvgdAIYZMSH8ovqU/XU4HUgy4XSuD0rmWg/Q EXRcbxjpnYQ75uXPA1QznlSMGSk14GvFXxHJv/OsNj/Hnj7ztu8lMjusvTW8/fAYLhxi UYYw== X-Gm-Message-State: AGi0Pua2Y+J6ri/dnMwMV5o9Hz5JXQ6ws5yrJo2YWogaLbXwuNNG1rYA 9AhnRiMVGlC0UCINiiEyqKywl6tt4OcDM/ThiN3JgBGxuAA= X-Google-Smtp-Source: APiQypJlvmM9DkOCGXg8xbIlhY8ENuSISFOq0CQrB2x/1nic1RUStzQN1QU6PM//NcTtbzqfJhInFa2Pak/UWVrGuoE= X-Received: by 2002:a1c:7308:: with SMTP id d8mr19362622wmb.6.1589325894086; Tue, 12 May 2020 16:24:54 -0700 (PDT) MIME-Version: 1.0 From: Mauro Aranda Date: Tue, 12 May 2020 20:24:42 -0300 Message-ID: Subject: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables To: bug-gnu-emacs Content-Type: multipart/alternative; boundary="00000000000059742d05a57bc547" Received-SPF: pass client-ip=2a00:1450:4864:20::32e; envelope-from=maurooaranda@gmail.com; helo=mail-wm1-x32e.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-Spam-Score: 0.6 (/) X-Debbugs-Envelope-To: submit X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -2.3 (--) --00000000000059742d05a57bc547 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I found this problem with matrices larger than 3x3. Consider a matrix like this: 1 0 0 0 0 1 0 0 0 0 0 1 0 0 a 0 Its determinant is -a, but Calc says its 0. Steps to reproduce: 1) emacs -Q 2) Start Calc: C-x * c 3) Enter algebraic mode by typing ' 4) Enter the above matrix, like this: [[1 0 0 0][0 1 0 0][0 0 0 1][0 0 a 0]] 5) Calculate the determinant: V D Calc says that the determinant is 0, which is wrong. If, however, a is replaced with a value, say 5, Calc correctly solves it and reports the determinant as -5. With a 3x3 matrix, the result is correct. That is: V D on [[1 0 0][0 0 1][0 a 0]] gives -a as the result. I think the algorithm for choosing the pivots should be improved to be able to permutate the rows and choose a symbolic variable as the pivot. In GNU Emacs 28.0.50 (build 7, x86_64-pc-linux-gnu, GTK+ Version 3.22.30, cairo version 1.15.10) of 2020-05-12 built on tbb-desktop Repository revision: 703115829b35de6a90d7bafb7931f905e79d0d35 Repository branch: master Windowing system distributor 'The X.Org Foundation', version 11.0.12005000 System Description: Ubuntu 18.04.4 LTS Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. C-x * (Type ? for a list of Calc options) Welcome to the GNU Emacs Calculator! Press =E2=80=98?=E2=80=99 or =E2=80= =98h=E2=80=99 for help, =E2=80=98q=E2=80=99 to quit Working... LUD step =3D 3/4 C-x * (Type ? for a list of Calc options) Configured features: XPM JPEG TIFF GIF PNG CAIRO SOUND DBUS GSETTINGS GLIB NOTIFY INOTIFY GNUTLS FREETYPE HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS PDUMPER GMP Important settings: value of $LC_MONETARY: es_AR.UTF-8 value of $LC_NUMERIC: es_AR.UTF-8 value of $LC_TIME: es_AR.UTF-8 value of $LANG: en_US.UTF-8 locale-coding-system: utf-8-unix Major mode: Lisp Interaction Minor modes in effect: tooltip-mode: t global-eldoc-mode: t eldoc-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs format-spec rfc822 mml mml-sec password-cache epa derived epg epg-config gnus-util rmail rmail-loaddefs text-property-search time-date subr-x seq byte-opt gv bytecomp byte-compile cconv mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils calc-arith calc-mtx calccomp calc-alg calc-vec calc-aent calc-menu easymenu calc-misc calc-prog calc-ext cl-loaddefs cl-lib calc calc-loaddefs calc-macs tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote threads dbusbind inotify dynamic-setting system-font-setting font-render-setting cairo move-toolbar gtk x-toolkit x multi-tty make-network-process emacs) Memory information: ((conses 16 76586 9357) (symbols 48 9259 1) (strings 32 22656 1028) (string-bytes 1 685264) (vectors 16 11989) (vector-slots 8 156067 9126) (floats 8 28 37) (intervals 56 207 0) (buffers 992 12)) --00000000000059742d05a57bc547 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I found this problem with matrices larger than 3x3.
Consider a matrix like this:
1 0 0 0
0 1 0 0
0 0 0 1
0 0 a 0
Its determinant is -a, but Calc says its 0.

Steps to reproduce= :

1) emacs -Q
2) Start Calc: C-x * c
3) Enter algebraic mode b= y typing '
4) Enter the above matrix, like this:
[[1 0 0 0][0 1 0= 0][0 0 0 1][0 0 a 0]]
5) Calculate the determinant: V D

Calc say= s that the determinant is 0, which is wrong.

If, however, a is repla= ced with a value, say 5, Calc correctly solves it
and reports the determ= inant as -5.

With a 3x3 matrix, the result is correct.=C2=A0 That is= :
V D on [[1 0 0][0 0 1][0 a 0]] gives -a as the result.

I think the algorithm for choosing the pivots should be improved to= be
able to permutate the rows and choose a symbolic variable as the piv= ot.

In GNU Emacs 28.0.50 (build 7, x86_64-pc-linux-gnu, GTK+ = Version 3.22.30, cairo version 1.15.10)
=C2=A0of 2020-05-12 built on t= bb-desktop
Repository revision: 703115829b35de6a90d7bafb7931f905e79d0d35=
Repository branch: master
Windowing system distributor 'The X.Or= g Foundation', version 11.0.12005000
System Description: Ubuntu 18.0= 4.4 LTS

Recent messages:
For information about GNU Emacs and the = GNU system, type C-h C-a.
C-x * =C2=A0(Type ? for a list of Calc options= )
Welcome to the GNU Emacs Calculator!=C2=A0 Press =E2=80=98?=E2=80=99 o= r =E2=80=98h=E2=80=99 for help, =E2=80=98q=E2=80=99 to quit
Working... L= UD step =3D 3/4
C-x * =C2=A0(Type ? for a list of Calc options)

C= onfigured features:
XPM JPEG TIFF GIF PNG CAIRO SOUND DBUS GSETTINGS GLI= B NOTIFY INOTIFY
GNUTLS FREETYPE HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS GTK3 = X11 XDBE XIM
MODULES THREADS PDUMPER GMP

Important settings:
= =C2=A0 value of $LC_MONETARY: es_AR.UTF-8
=C2=A0 value of $LC_NUMERIC: e= s_AR.UTF-8
=C2=A0 value of $LC_TIME: es_AR.UTF-8
=C2=A0 value of $LAN= G: en_US.UTF-8
=C2=A0 locale-coding-system: utf-8-unix

Major mode= : Lisp Interaction

Minor modes in effect:
=C2=A0 tooltip-mode: t<= br>=C2=A0 global-eldoc-mode: t
=C2=A0 eldoc-mode: t
=C2=A0 electric-i= ndent-mode: t
=C2=A0 mouse-wheel-mode: t
=C2=A0 tool-bar-mode: t
= =C2=A0 menu-bar-mode: t
=C2=A0 file-name-shadow-mode: t
=C2=A0 global= -font-lock-mode: t
=C2=A0 font-lock-mode: t
=C2=A0 blink-cursor-mode:= t
=C2=A0 auto-composition-mode: t
=C2=A0 auto-encryption-mode: t
= =C2=A0 auto-compression-mode: t
=C2=A0 line-number-mode: t
=C2=A0 tra= nsient-mark-mode: t

Load-path shadows:
None found.

Feature= s:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs=
format-spec rfc822 mml mml-sec password-cache epa derived epg epg-confi= g
gnus-util rmail rmail-loaddefs text-property-search time-date subr-x s= eq
byte-opt gv bytecomp byte-compile cconv mm-decode mm-bodies mm-encode=
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
= rfc2045 ietf-drums mm-util mail-prsvr mail-utils calc-arith calc-mtx
cal= ccomp calc-alg calc-vec calc-aent calc-menu easymenu calc-misc
calc-prog= calc-ext cl-loaddefs cl-lib calc calc-loaddefs calc-macs
tooltip eldoc = electric uniquify ediff-hook vc-hooks lisp-float-type
mwheel term/x-win = x-win term/common-win x-dnd tool-bar dnd fontset image
regexp-opt fringe= tabulated-list replace newcomment text-mode elisp-mode
lisp-mode prog-m= ode register page tab-bar menu-bar rfn-eshadow isearch
timer select scro= ll-bar mouse jit-lock font-lock syntax facemenu
font-core term/tty-color= s frame minibuffer cl-generic cham georgian
utf-8-lang misc-lang vietnam= ese tibetan thai tai-viet lao korean
japanese eucjp-ms cp51932 hebrew gr= eek romanian slovak czech european
ethiopic indian cyrillic chinese comp= osite charscript charprop
case-table epa-hook jka-cmpr-hook help simple = abbrev obarray
cl-preloaded nadvice loaddefs button faces cus-face macro= exp files
text-properties overlay sha1 md5 base64 format env code-pages = mule
custom widget hashtable-print-readable backquote threads dbusbindinotify dynamic-setting system-font-setting font-render-setting cairo
= move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

M= emory information:
((conses 16 76586 9357)
=C2=A0(symbols 48 9259 1)<= br>=C2=A0(strings 32 22656 1028)
=C2=A0(string-bytes 1 685264)
=C2=A0= (vectors 16 11989)
=C2=A0(vector-slots 8 156067 9126)
=C2=A0(floats 8= 28 37)
=C2=A0(intervals 56 207 0)
=C2=A0(buffers 992 12))
--00000000000059742d05a57bc547-- From debbugs-submit-bounces@debbugs.gnu.org Wed May 13 08:58:48 2020 Received: (at 41223) by debbugs.gnu.org; 13 May 2020 12:58:48 +0000 Received: from localhost ([127.0.0.1]:57647 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jYqyG-00086e-3Y for submit@debbugs.gnu.org; Wed, 13 May 2020 08:58:48 -0400 Received: from mail1480c50.megamailservers.eu ([91.136.14.80]:57244 helo=mail118c50.megamailservers.eu) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jYqyC-00086L-Qa for 41223@debbugs.gnu.org; Wed, 13 May 2020 08:58:47 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1589374715; bh=aLlYVS2PCl9e6wKib2NghO3l/rIQyShtvoL8VaHLU08=; h=From:Subject:Date:Cc:To:From; b=TNBWSmsPLK3eZBdWqChpXfW8suloJMke8lOryDNCX4j1eeVR5sEguW3GODoK4c277 eTSGaWLdm/Eqp2vZIKxvktPK+IeE+PTW3pn/s9DyEHD5SW2OJahswS8Z97UkhTkvX3 Wx8TQjowHwGHUVMgIX+tQ8vdDxdEsk0QuNFcvYxk= Feedback-ID: mattiase@acm.or Received: from stanniol.lan (c-4e4ae655.032-75-73746f71.bbcust.telenor.se [85.230.74.78]) (authenticated bits=0) by mail118c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id 04DCwXIH023701; Wed, 13 May 2020 12:58:35 +0000 From: =?utf-8?Q?Mattias_Engdeg=C3=A5rd?= Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.14\)) Subject: bug#41223: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables Message-Id: Date: Wed, 13 May 2020 14:58:33 +0200 To: Mauro Aranda X-Mailer: Apple Mail (2.3445.104.14) X-CTCH-RefID: str=0001.0A782F26.5EBBEEB2.009F, 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-Rules: X-CTCH-Flags: 0 X-CTCH-ScoreCust: 0.000 X-CSC: 0 X-CHA: v=2.3 cv=KaGsTjQD c=1 sm=1 tr=0 a=klNLuyVZdLUgl+K5Uafb2A==:117 a=klNLuyVZdLUgl+K5Uafb2A==:17 a=kj9zAlcOel0A:10 a=8z6JA8MJd_sA:10 a=M51BFTxLslgA:10 a=z0kmUskR1w02NVpta3kA:9 a=w2WOszxD3TwRewte:21 a=1vXBW5M9s8K8Bu2d:21 a=CjuIK1q_8ugA:10 X-Spam-Score: 1.2 (+) X-Spam-Report: Spam detection software, running on the system "debbugs.gnu.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Thank you for reporting this. If Calc cannot compute something, at least it shouldn't lie. In this case I'm tempted to apply the expedient below. Would that suffice for you? --- a/lisp/calc/calc-mtx.el +++ b/lisp/calc/calc-mtx.el @@ -275,7 +275,7 @@ math-do-matrix-lud k (1+ k))) (setcar (nthcdr j (nth i lu)) sum) (let ((dum (math-lud-pivot-check sum))) - (if (Math-lessp b [...] Content analysis details: (1.2 points, 10.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: megamailservers.eu] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 1.0 SPF_SOFTFAIL SPF: sender does not match SPF record (softfail) 0.3 KHOP_HELO_FCRDNS Relay HELO differs from its IP's reverse DNS X-Debbugs-Envelope-To: 41223 Cc: 41223@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -0.0 (/) Thank you for reporting this. If Calc cannot compute something, at least = it shouldn't lie. In this case I'm tempted to apply the expedient below. Would that = suffice for you? --- a/lisp/calc/calc-mtx.el +++ b/lisp/calc/calc-mtx.el @@ -275,7 +275,7 @@ math-do-matrix-lud k (1+ k))) (setcar (nthcdr j (nth i lu)) sum) (let ((dum (math-lud-pivot-check sum))) - (if (Math-lessp big dum) + (if (or (math-zerop big) (Math-lessp big dum)) (setq big dum imax i))) (setq i (1+ i))) From debbugs-submit-bounces@debbugs.gnu.org Wed May 13 18:16:09 2020 Received: (at 41223) by debbugs.gnu.org; 13 May 2020 22:16:09 +0000 Received: from localhost ([127.0.0.1]:59751 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jYzfd-0003Wy-Ce for submit@debbugs.gnu.org; Wed, 13 May 2020 18:16:09 -0400 Received: from mail-wm1-f42.google.com ([209.85.128.42]:34728) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jYzfc-0003Wa-C8 for 41223@debbugs.gnu.org; Wed, 13 May 2020 18:16:08 -0400 Received: by mail-wm1-f42.google.com with SMTP id g14so12870497wme.1 for <41223@debbugs.gnu.org>; Wed, 13 May 2020 15:16:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=cRUAaXPWMBmxhxDu3p1XSGo4WC0o1GuF1h9k2tW1PIM=; b=WoeS5TJLR9ujIX5Tdibr4ATnu0s8e+Z2J4tfHRTq+kxFfMl8PssNS4B/Jwlu0TAlMG TAwOxIRSFPsTp/FSty3vXnnQxn7fnnZVM2GnmzE2eJndBTL88qmVAHupZzzPO/GAWmjG E/OuKZJxABmCZB6r+973JFItQafGHHvCCcEOHH9+7EtvBDnW+m1TuOPgPyrQCBqzfDPV aFmJ/dJ+8Da0LgyzpLLBbweXfUu1xW6gUnUaKoBtK1kAbXLfG9C+CBHkeRETn1WcKCNX yHvlW5QPvLWUjMjw+wSqbUx0zUTxt6pNCeA82w4HhppuskAbH69V8zPMbmXyEF3X1b0L +sjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=cRUAaXPWMBmxhxDu3p1XSGo4WC0o1GuF1h9k2tW1PIM=; b=nUdoniq+0TCOCVj4sS2+k5i+5efx/H6v6cOoIY0CEvp0vpwv3d5rVAQwGsrs/X/xj7 CAkTAaa8+seN/saRFFlsZrHaaJNrbpBfniIsDp3Zegd5ztEiKQ7SgmFnLxxCEdHt++y0 tMy+h/y1mAikoJrb4HoTB3LabqL21U6JB3VBl1Gfo9SSmsJ0g6rff70/W2jnEruc2hBw mqc6OIBG0qw4SCw51XrXcxTWOyx1XAmQUVCwbl2SzaecLp5sKnMaU9hcP31R2bfADc+n I2p39mVvWbI3KGM9Yf9y6Qcw2WvzG5hVUgV/T2JsXpkFE0eaeeakpsIiB8DmLoWWc1ls mbTQ== X-Gm-Message-State: AGi0Publc5FPzQFXzch6irYUF39tHy65SOPejNFW/laW/0tnmLkOUUx2 SobSzccDBNN0pXpEclYBhSrqzhccAGYieEeD+XA= X-Google-Smtp-Source: APiQypIufBRf/TJlGI3i+n9129KX+Xx4Kw/ROip7pXC0QROT6Ob7uyzYBwIDTmUUdtUT1WdLzO+Y/I25I+1Fr/u3vPg= X-Received: by 2002:a1c:a74a:: with SMTP id q71mr31846406wme.23.1589408162581; Wed, 13 May 2020 15:16:02 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Mauro Aranda Date: Wed, 13 May 2020 19:15:48 -0300 Message-ID: Subject: Re: bug#41223: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables To: =?UTF-8?Q?Mattias_Engdeg=C3=A5rd?= Content-Type: multipart/alternative; boundary="000000000000ef10a905a58eec31" X-Spam-Score: 0.0 (/) X-Debbugs-Envelope-To: 41223 Cc: 41223@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -1.0 (-) --000000000000ef10a905a58eec31 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mattias Engdeg=C3=A5rd writes: Hello Mattias. > Thank you for reporting this. If Calc cannot compute something, at least it shouldn't lie. Agreed. And thank you for taking care of this so quickly. > In this case I'm tempted to apply the expedient below. Would that suffice for you? > > --- a/lisp/calc/calc-mtx.el > +++ b/lisp/calc/calc-mtx.el > @@ -275,7 +275,7 @@ math-do-matrix-lud > k (1+ k))) > (setcar (nthcdr j (nth i lu)) sum) > (let ((dum (math-lud-pivot-check sum))) > - (if (Math-lessp big dum) > + (if (or (math-zerop big) (Math-lessp big dum)) > (setq big dum > imax i))) > (setq i (1+ i))) It is good enough for me. Thanks. Best regards, Mauro. --000000000000ef10a905a58eec31 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Mattias Engdeg=C3=A5rd <mattiase@acm.org> writes:

Hello Mattias.

> Tha= nk you for reporting this. If Calc cannot compute something, at least it sh= ouldn't lie.

Agreed.=C2=A0 And thank you for taking care of this= so quickly.

> In this case I'm tempted to apply the expedien= t below. Would that suffice for you?
>
> --- a/lisp/calc/calc-m= tx.el
> +++ b/lisp/calc/calc-mtx.el
> @@ -275,7 +275,7 @@ math-= do-matrix-lud
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 k (1+ k)))
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 (setcar (nthcdr j (nth i= lu)) sum)
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 (let ((dum (math-lud-pivot-c= heck sum)))
> - =C2=A0 =C2=A0 =C2=A0 =C2=A0 (if (Math-lessp big dum)<= br>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 (if (or (math-zerop big) (Math-lessp = big dum))
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 (setq bi= g dum
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 imax i)))
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 (setq i (1+ i)))
It is good enough for me.=C2=A0 Thanks.

Best regards,
Mauro= .
--000000000000ef10a905a58eec31-- From debbugs-submit-bounces@debbugs.gnu.org Thu May 14 04:43:41 2020 Received: (at 41223-done) by debbugs.gnu.org; 14 May 2020 08:43:41 +0000 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 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 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 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.14\)) Subject: Re: bug#41223: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables From: =?utf-8?Q?Mattias_Engdeg=C3=A5rd?= In-Reply-To: Date: Thu, 14 May 2020 10:43:19 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <7A33094E-BD4C-45DE-A57D-F23D50CFC6B4@acm.org> References: To: Mauro Aranda 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-Rules: 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-Spam-Score: 1.2 (+) X-Spam-Report: Spam detection software, running on the system "debbugs.gnu.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: 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. Content analysis details: (1.2 points, 10.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: megamailservers.eu] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 1.0 SPF_SOFTFAIL SPF: sender does not match SPF record (softfail) 0.3 KHOP_HELO_FCRDNS Relay HELO differs from its IP's reverse DNS X-Debbugs-Envelope-To: 41223-done Cc: 41223-done@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -0.0 (/) 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). From debbugs-submit-bounces@debbugs.gnu.org Thu May 14 05:57:02 2020 Received: (at 41223) by debbugs.gnu.org; 14 May 2020 09:57:02 +0000 Received: from localhost ([127.0.0.1]:60286 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jZAbt-0000eZ-MA for submit@debbugs.gnu.org; Thu, 14 May 2020 05:57:01 -0400 Received: from mail1444c50.megamailservers.eu ([91.136.14.44]:41274 helo=mail264c50.megamailservers.eu) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jZAbq-0000e9-F8 for 41223@debbugs.gnu.org; Thu, 14 May 2020 05:56:59 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1589450210; bh=q1DDzLY107fKdU15vJYhOP/Wfufb6dwkzgYCuEidJTc=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=NZ2IqTidB0/Tvl65EbDu79sL74CJXcJ7Wn8lOkTQiC6O8VbMEkCVpKmUbbxVUW4KY 8ZuTBaAOJCIKd72g8lolhKyanjg8fNzDdoCaa8opl9XJtLmLLpQn/Tf/bKXQrG5l+3 i/Sv9u6upR1V0WEozcq0ZxtXs37QeBTDsyPIC9eU= Feedback-ID: mattiase@acm.or Received: from stanniol.lan (c-4e4ae655.032-75-73746f71.bbcust.telenor.se [85.230.74.78]) (authenticated bits=0) by mail264c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id 04E9umoP011065; Thu, 14 May 2020 09:56:49 +0000 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.14\)) Subject: Re: bug#41223: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables From: =?utf-8?Q?Mattias_Engdeg=C3=A5rd?= In-Reply-To: <7A33094E-BD4C-45DE-A57D-F23D50CFC6B4@acm.org> Date: Thu, 14 May 2020 11:56:47 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <2CF164B5-2BB9-4740-BF86-FA9CA721672D@acm.org> References: <7A33094E-BD4C-45DE-A57D-F23D50CFC6B4@acm.org> To: Mauro Aranda X-Mailer: Apple Mail (2.3445.104.14) X-CTCH-RefID: str=0001.0A782F25.5EBD1576.0082, 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-Rules: X-CTCH-Flags: 0 X-CTCH-ScoreCust: 0.000 X-CSC: 0 X-CHA: v=2.3 cv=PPNxBsiC c=1 sm=1 tr=0 a=klNLuyVZdLUgl+K5Uafb2A==:117 a=klNLuyVZdLUgl+K5Uafb2A==:17 a=kj9zAlcOel0A:10 a=M51BFTxLslgA:10 a=XclehxbK_wuC0LPE3NcA:9 a=CjuIK1q_8ugA:10 X-Spam-Score: 1.2 (+) X-Spam-Report: Spam detection software, running on the system "debbugs.gnu.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: By the way, the change also fixes inversion of matrices such as the one in your example. Previously, Calc would (erroneously) complain that the matrix was singular. Content analysis details: (1.2 points, 10.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: megamailservers.eu] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 1.0 SPF_SOFTFAIL SPF: sender does not match SPF record (softfail) 0.3 KHOP_HELO_FCRDNS Relay HELO differs from its IP's reverse DNS X-Debbugs-Envelope-To: 41223 Cc: 41223@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -0.0 (/) By the way, the change also fixes inversion of matrices such as the one = in your example. Previously, Calc would (erroneously) complain that the = matrix was singular. From debbugs-submit-bounces@debbugs.gnu.org Thu May 14 07:42:00 2020 Received: (at 41223) by debbugs.gnu.org; 14 May 2020 11:42:00 +0000 Received: from localhost ([127.0.0.1]:60513 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jZCFT-0006Ct-SZ for submit@debbugs.gnu.org; Thu, 14 May 2020 07:42:00 -0400 Received: from mail-wr1-f50.google.com ([209.85.221.50]:33285) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jZCFS-0006Cc-7B for 41223@debbugs.gnu.org; Thu, 14 May 2020 07:41:58 -0400 Received: by mail-wr1-f50.google.com with SMTP id l11so3615892wru.0 for <41223@debbugs.gnu.org>; Thu, 14 May 2020 04:41:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YVlgzkFHwkFGoGasT0X1HWaSWYirwYISJ7dbiEvi4Vw=; b=O39BCnzh8I05GCpPd7xtm2Lio61Nn1nEWiSeOuLcJZwAYARVq9qttyMjXoL2bkVAUp l0GaLF5gfcjIKwmNEuolu6cyxUH78VIblCHbC0DrubbB6z8hk7l9PW+zU9FDJ+2aafzh CF+PIg62nghHrmXzES2gyeyM13IwC0Fs7/EftAAs+bxG68aLQb+cIk9Wd0Rx5Ob5SyEw 4leEOkbD+QfnkyxSUTZRlE4n0AJVPfhBgEwQUj2c2IF1bkG1gGBCI6jg2rniW083GKay ssx9xe0wrFH/CzH+uDqPH/HFvh1SkS7CnrOSG+0mt8sAO5/dPZxoyQCm0AzUM9Dx0eDl JDoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=YVlgzkFHwkFGoGasT0X1HWaSWYirwYISJ7dbiEvi4Vw=; b=DfNez6+PqXA4Z1mfG3FW8HPb6DOhoTWDrzweKM/ItVhGFg7oPLyPWhc0zCiX5i2eNl WXITn/q1uDggQ81IAu0q4Kvt7ht+lJlIZ6+gmo4skKveVctsncNZApZHXCC0pbrMTFE8 W7l13J8QsSrO4Yk48fnsywPEocmbsQRfWqSDP6uv+n9NziML2W8WqYSszUtFV9SDlXi6 P+EcxB3bx8VhtG29ys8q6TT+e5AMcB2iJkVX7+PBcgDCEQH+TecSuwjDkOuovTOkc0Dd DAa6LJUBcCxq5X9EazRV4DLqfPKYLAydBho9uJ+BsWaKIobvb2dgdlAs6M0qCp7ctWfm KR8A== X-Gm-Message-State: AOAM531QJp/Xs1Vxj0FmPBLzdnG+bPLXOh7vkrgmdplvv7LxyobtZUST Uj6VwSDKexUbcX0l5gZvuOaqTo4w3yBwYLGMCgg= X-Google-Smtp-Source: ABdhPJz8RE08OpjzEg5sZkOkqz3IoGbk9qlrMPwfpTbsLrQm3XK4IWaDWHCFGsTiLv4SvNc+jfCm60BN+ETUfoIVPXU= X-Received: by 2002:adf:f786:: with SMTP id q6mr4958755wrp.120.1589456512562; Thu, 14 May 2020 04:41:52 -0700 (PDT) MIME-Version: 1.0 References: <7A33094E-BD4C-45DE-A57D-F23D50CFC6B4@acm.org> In-Reply-To: <7A33094E-BD4C-45DE-A57D-F23D50CFC6B4@acm.org> From: Mauro Aranda Date: Thu, 14 May 2020 08:41:40 -0300 Message-ID: Subject: Re: bug#41223: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables To: =?UTF-8?Q?Mattias_Engdeg=C3=A5rd?= Content-Type: multipart/alternative; boundary="000000000000d138a705a59a2ee4" X-Spam-Score: 0.0 (/) X-Debbugs-Envelope-To: 41223 Cc: 41223@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -1.0 (-) --000000000000d138a705a59a2ee4 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mattias Engdeg=C3=A5rd writes: > 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). I see. Yes, using a fraction-free algorithm would be good. But for the moment, getting bc(ad-1) as the result is one `j M' away. --000000000000d138a705a59a2ee4 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Mattias Engdeg=C3=A5rd <mattiase@acm.org> writes:

> No doubt there are better= ways of computing the determinant for
> non-numeric matrices. In par= ticular, division shouldn't be necessary
> at all, and the curren= t algorithm results in some untidy
> expressions. For example, the de= terminant of
>
> [a 0 0 1]
> [0 b 0 0]
> [0 0 c 0]<= br>> [1 0 0 d]
>
> is given as abc*(d-1/a), falsely giving t= he impression of being
> undefined for a=3D0, rather than bc(ad-1).
I see.=C2=A0 Yes, using a fraction-free algorithm would be good.=C2= =A0 But for the
moment, getting bc(ad-1) as the result is one `j M' = away.
--000000000000d138a705a59a2ee4-- From debbugs-submit-bounces@debbugs.gnu.org Thu May 14 07:50:12 2020 Received: (at 41223) by debbugs.gnu.org; 14 May 2020 11:50:12 +0000 Received: from localhost ([127.0.0.1]:60529 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jZCNQ-0006Ut-Hw for submit@debbugs.gnu.org; Thu, 14 May 2020 07:50:12 -0400 Received: from mail-wm1-f48.google.com ([209.85.128.48]:36787) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jZCNO-0006UL-MR for 41223@debbugs.gnu.org; Thu, 14 May 2020 07:50:11 -0400 Received: by mail-wm1-f48.google.com with SMTP id w19so17467634wmc.1 for <41223@debbugs.gnu.org>; Thu, 14 May 2020 04:50:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=sE/7HAmKyeL3Yu1zeVV6Hu6+/MeOCzJQZXNl2+nlxgs=; b=nCm0OFzMGRNJAFZtLJ+ah4rlOrJ7xBNcrQxWKHv6IwzN46vdOgOlp5fLWTo8anZZ1W Ur4nLK1FOYNJvo5XR9yoii/UclI5V/BTKSlGTaL03xl+dD32cIkaSZC86zBp2+Ghxqqa o0oGlKaHwDIjpmgMPY/CGP5eMzxnxNGLHniS0/82U8iamAf+esxQmlBFnP7thVbmM/Dg iBFPqFVZceG0ihe4ohjkUHB19YPooAryaid80sdJYkiXxEKNevUk18IIb6iiVr7AZaGS i59vS2z24naaqTkDDK9HaeQG/xMRVsIC9psM9uYz9Sua5paYxGwLi65NB4o0YUVQj4n3 tgFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=sE/7HAmKyeL3Yu1zeVV6Hu6+/MeOCzJQZXNl2+nlxgs=; b=SllmVf0QS5++TrpvP2cMSKCzvGE4FacAiSEzJnhHGMIG878GwVozeVjyUxaZ4mfWFo rGI2yThktcp30Yya2fakJCe+q0W69G4C3/VpBnlapwaSfgNRvdrhJK9UA3OIfKq23Q6N PwXHVU0TRZecaZLOPdZ3I2vpbCurn3NyWo8zgHZ7WBRNTm35HxUgYRBxF2mu5XuOdsSY WAfkkuzTivZiaZodYBelE3f6GRYA3hzRCcYJ2zYPuVojPHbJqgfZZtGCQq5EzLttiVOq b2yFFY3viJoFEblZV9nlgKMERtTHJraGDnt14hKRWTwm/Bv4T7ZbCYHJ0jPoNc+cVjkB v4wA== X-Gm-Message-State: AGi0PuZCmSlV6wB5gZOIV4/c+Rd9CFb+bzTQfzk4+SMD9PjEoc6VxVGx uJGy8uJlbozmg3vSqzL+tNU86v3cKdLmKL4Pl6A= X-Google-Smtp-Source: APiQypLUJ83Rbl3uVUKoEnGsV6bdH2Jyz+qhKsdBl+RUeWivO5tQZg3hQp1qne71OEtGy/fJSEYKOuim1E1xHexnUM8= X-Received: by 2002:a1c:6156:: with SMTP id v83mr37263275wmb.28.1589457004776; Thu, 14 May 2020 04:50:04 -0700 (PDT) MIME-Version: 1.0 References: <7A33094E-BD4C-45DE-A57D-F23D50CFC6B4@acm.org> <2CF164B5-2BB9-4740-BF86-FA9CA721672D@acm.org> In-Reply-To: <2CF164B5-2BB9-4740-BF86-FA9CA721672D@acm.org> From: Mauro Aranda Date: Thu, 14 May 2020 08:49:51 -0300 Message-ID: Subject: Re: bug#41223: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables To: =?UTF-8?Q?Mattias_Engdeg=C3=A5rd?= Content-Type: multipart/alternative; boundary="00000000000027d02005a59a4cb7" X-Spam-Score: 0.0 (/) X-Debbugs-Envelope-To: 41223 Cc: 41223@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -1.0 (-) --00000000000027d02005a59a4cb7 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mattias Engdeg=C3=A5rd writes: > By the way, the change also fixes inversion of matrices such as the > one in your example. Previously, Calc would (erroneously) complain > that the matrix was singular. Ah, yes. I tested that, but forgot to include it in the bug report. Thanks again! --00000000000027d02005a59a4cb7 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Mattias Engdeg=C3=A5rd <mattiase@acm.org> writes:

> By the way, the change al= so fixes inversion of matrices such as the
> one in your example. Pre= viously, Calc would (erroneously) complain
> that the matrix was sing= ular.

Ah, yes.=C2=A0 I tested that, but forgot to include it in= the bug report.

Thanks again!
--00000000000027d02005a59a4cb7-- From unknown Mon Jun 23 00:35:17 2025 Received: (at fakecontrol) by fakecontrolmessage; To: internal_control@debbugs.gnu.org From: Debbugs Internal Request Subject: Internal Control Message-Id: bug archived. Date: Fri, 12 Jun 2020 11:24:05 +0000 User-Agent: Fakemail v42.6.9 # This is a fake control message. # # The action: # bug archived. thanks # This fakemail brought to you by your local debbugs # administrator