From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.emacs.help Subject: Re: Non-Commutative calculations in Calc, Revisited Date: Thu, 06 Oct 2005 15:42:40 +0200 Organization: Organization?!? Message-ID: <851x2yu5gv.fsf@lola.goethe.zz> References: <878xx66b1c.fsf@vh213602.truman.edu> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1128611122 5693 80.91.229.2 (6 Oct 2005 15:05:22 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 6 Oct 2005 15:05:22 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Oct 06 17:05:14 2005 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1ENXHQ-0005VO-TL for geh-help-gnu-emacs@m.gmane.org; Thu, 06 Oct 2005 17:03:33 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ENXHO-0003Cv-Ul for geh-help-gnu-emacs@m.gmane.org; Thu, 06 Oct 2005 11:03:31 -0400 Original-Path: shelby.stanford.edu!newsfeed.stanford.edu!newsfeed.berkeley.edu!ucberkeley!newsfeed.arcor.de!news.arcor.de!not-for-mail Original-Newsgroups: gnu.emacs.help X-Face: 2FEFf>]>q>2iw=B6, xrUubRI>pR&Ml9=ao@P@i)L:\urd*t9M~y1^:+Y]'C0~{mAl`oQuAl \!3KEIp?*w`|bL5qr,H)LFO6Q=qx~iH4DN; i"; /yuIsqbLLCh/!U#X[S~(5eZ41to5f%E@'ELIi$t^ Vc\LWP@J5p^rst0+('>Er0=^1{]M9!p?&:\z]|;&=NP3AhB!B_bi^]Pfkw User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.50 (gnu/linux) Cancel-Lock: sha1:i0DhyBEBD8Dceptn9zVnpsyb/k4= Original-Lines: 16 Original-NNTP-Posting-Date: 06 Oct 2005 15:42:40 MEST Original-NNTP-Posting-Host: b38eb5ae.newsread2.arcor-online.net Original-X-Trace: DXC=>@fiSWE; _h; 2j7j^L?86D8Q5U85hF6f; 4jW\KbG]kaM8GSi?jHD8GO0`0UN??^NEd:1_LiI6ENVa=3>5MOK` List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:29976 Archived-At: Jay Belanger writes: > Neon Absentius writes: > >> When in non-commutative (aka `matrix') mode calc calculates >> (a b)^-1 to be a^-1 b^-1 instead of the correct b^-1 a^-1. Uh, what's correct about b^-1 a^-1? Set a=[1,1], b=[1;0], then (a b)^-1 = [1], and neither b^-1 nor a^-1 exist. This only works with a and b being square matrices. -- David Kastrup, Kriemhildstr. 15, 44793 Bochum