From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Neon Absentius Newsgroups: gmane.emacs.help Subject: Re: Non-commutative symbolic multiplication in Calc Date: Tue, 6 Sep 2005 19:12:48 +0000 Message-ID: <20050906191248.GB12694@SDF.LONESTAR.ORG> References: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1126034564 13007 80.91.229.2 (6 Sep 2005 19:22:44 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 6 Sep 2005 19:22:44 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Sep 06 21:22:34 2005 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1ECj0k-0002r4-2T for geh-help-gnu-emacs@m.gmane.org; Tue, 06 Sep 2005 21:21:38 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ECj0W-0003fM-Pt for geh-help-gnu-emacs@m.gmane.org; Tue, 06 Sep 2005 15:21:24 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1ECizk-0003Wi-Eh for help-gnu-emacs@gnu.org; Tue, 06 Sep 2005 15:20:36 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1ECizf-0003R6-6I for help-gnu-emacs@gnu.org; Tue, 06 Sep 2005 15:20:33 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ECizZ-0003OF-Cr for help-gnu-emacs@gnu.org; Tue, 06 Sep 2005 15:20:25 -0400 Original-Received: from [192.94.73.21] (helo=sdf.lonestar.org) by monty-python.gnu.org with esmtp (Exim 4.34) id 1ECiwM-0004rw-Vh for help-gnu-emacs@gnu.org; Tue, 06 Sep 2005 15:17:07 -0400 Original-Received: from sdf.lonestar.org (IDENT:absent@otaku.freeshell.org [192.94.73.2]) by sdf.lonestar.org (8.13.1/8.12.10) with ESMTP id j86JCmxm014257 for ; Tue, 6 Sep 2005 19:12:48 GMT Original-Received: (from absent@localhost) by sdf.lonestar.org (8.13.1/8.12.8/Submit) id j86JCmEA010692 for help-gnu-emacs@gnu.org; Tue, 6 Sep 2005 19:12:48 GMT Original-To: help-gnu-emacs@gnu.org Mail-Followup-To: Neon Absentius , help-gnu-emacs@gnu.org Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor 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:29265 Archived-At: On Tue, Sep 06, 2005 at 08:36:49PM +0200, Roland Winkler wrote: > Neon Absentius writes: > > Ideally the multiplication should not be assumed commutative (or the > > variables invertible) unless explicitly declared so. > > Emacs calc (the way I look at it) is designed to be a powerful, > advanced calculator. But it is not a computer algebra system which I > would use to address the kind of problem you are talking about.. > If there is a line between an advanced desk calculator and a CAS then surely Emacs calc has crossed it! OTOH what are PC's but (glorified) advanced desk calculators? :) But (more) seriously what I am talking about is not really that more complicated than what calc does already. If it can calculate 2 2 2 (x + y) = x + 2 y x + y then it should be able to do 2 2 2 (x + y) = x + x y + y x + y > For example. take a look at Maxima, http://www.ma.utexas.edu/maxima.html. > It's now under GPL, and it even has a nice emacs interface. Yes I know about maxima and I use it. However I usually prefer calc for a "quick and dirty" calculation. And I really like the interface. -- Most precious among the relics remaining of Peter's skeleton in the Vatican are 29 fragments of one of his skulls. (St. Peter's other skull is preserved in a reliquary at the Cathedral of St. John Lateran.) -- Frank R. Zindler, "Of Bones and Boners"