From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Lennart Borgman Newsgroups: gmane.emacs.devel Subject: Re: Elisp manual, node "Comparison of Numbers" Date: Mon, 29 May 2006 16:40:17 +0200 Message-ID: <447B07D1.8020503@student.lu.se> References: <85fyitc5w4.fsf@lola.goethe.zz> <447AFCFD.6030405@student.lu.se> <85bqtgditu.fsf@lola.goethe.zz> <447B02B8.6070201@student.lu.se> <857j44di4o.fsf@lola.goethe.zz> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: sea.gmane.org 1148913647 10128 80.91.229.2 (29 May 2006 14:40:47 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Mon, 29 May 2006 14:40:47 +0000 (UTC) Cc: "Kim F. Storm" , Drew Adams , Emacs-Devel Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon May 29 16:40:41 2006 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1Fkiv6-00051N-79 for ged-emacs-devel@m.gmane.org; Mon, 29 May 2006 16:40:36 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Fkiv5-0003Cd-OU for ged-emacs-devel@m.gmane.org; Mon, 29 May 2006 10:40:35 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Fkius-0003C0-J1 for emacs-devel@gnu.org; Mon, 29 May 2006 10:40:22 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Fkiur-0003Bg-Qn for emacs-devel@gnu.org; Mon, 29 May 2006 10:40:21 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Fkiur-0003Bd-JZ for emacs-devel@gnu.org; Mon, 29 May 2006 10:40:21 -0400 Original-Received: from [81.228.8.83] (helo=pne-smtpout1-sn2.hy.skanova.net) by monty-python.gnu.org with esmtp (Exim 4.52) id 1Fkj0P-0000qT-Fp; Mon, 29 May 2006 10:46:05 -0400 Original-Received: from [192.168.123.121] (83.249.218.244) by pne-smtpout1-sn2.hy.skanova.net (7.2.072.1) id 447421AF0010C77F; Mon, 29 May 2006 16:40:17 +0200 User-Agent: Thunderbird 1.5.0.2 (Windows/20060308) Original-To: David Kastrup In-Reply-To: <857j44di4o.fsf@lola.goethe.zz> X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:55432 Archived-At: David Kastrup wrote: >>> >>> >> Yes, in a sense you are right. I should have expressed my self a bit >> differently, but I am afraid you missed the point. The crucial thing >> is that you divide the difference with the "distance" from 0 to >> construct the number you compare to the fuzz factor. >> > > In which case, the relative distance from 0 is 1.0 for _any_ nonzero > number. And your point was? > This of course. > >> It seems reasonable to me but breaks down in the special case where >> one of the numbers are 0 (and the other is not). >> > > Relative measures don't work when comparing with 0. But 0.0 can > pretty much only come about by cancellation, and then comparison is > unreliable anyway. It might be worth pointing out, but it certainly > is not a remedy to rechristen a relative measure to absolute. > I guess that is true. So maybe it is better to ask Drew what he was going to compare so we can construct a better measurement.