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: ln(0), bug in Calc? Date: Thu, 6 Oct 2005 11:32:03 +0000 Message-ID: <20051006113203.GF992@SDF.LONESTAR.ORG> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1128601784 3857 80.91.229.2 (6 Oct 2005 12:29:44 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 6 Oct 2005 12:29:44 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Oct 06 14:29:35 2005 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1ENUqz-0001l5-DG for geh-help-gnu-emacs@m.gmane.org; Thu, 06 Oct 2005 14:28:06 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ENUqw-00036x-GE for geh-help-gnu-emacs@m.gmane.org; Thu, 06 Oct 2005 08:28:03 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1ENTzg-0001pv-8r for help-gnu-emacs@gnu.org; Thu, 06 Oct 2005 07:33:00 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1ENTza-0001pO-O8 for help-gnu-emacs@gnu.org; Thu, 06 Oct 2005 07:32:56 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ENTzZ-0001p7-CV for help-gnu-emacs@gnu.org; Thu, 06 Oct 2005 07:32:54 -0400 Original-Received: from [192.94.73.21] (helo=sdf.lonestar.org) by monty-python.gnu.org with esmtp (Exim 4.34) id 1ENTzY-0001ee-O7 for help-gnu-emacs@gnu.org; Thu, 06 Oct 2005 07:32:53 -0400 Original-Received: from sdf.lonestar.org (IDENT:absent@ukato.freeshell.org [192.94.73.7]) by sdf.lonestar.org (8.13.1/8.12.10) with ESMTP id j96BW3Oc027129 for ; Thu, 6 Oct 2005 11:32:03 GMT Original-Received: (from absent@localhost) by sdf.lonestar.org (8.13.1/8.12.8/Submit) id j96BW361023252 for help-gnu-emacs@gnu.org; Thu, 6 Oct 2005 11:32:03 GMT Original-To: help-gnu-emacs@gnu.org Mail-Followup-To: Neon Absentius , help-gnu-emacs@gnu.org Content-Disposition: inline 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:29973 Archived-At: When asked to solve the equation e^x = 0, Calc returns ln(0) as the answer. It indicates in the echo area: Logarithm of zero: 0 [w=more] ;; I press w Choosing 0 for arbitrary integer in solution [w=more] ;; I press w Logarithm of zero: 0 [w=more] ;; I press w Number expected: e [w=more] ;; I press w Number expected: e ;; I press w (No further explanations available) Apparently when the argument of log is non-positive Calc switches to the (multivalued) complex logarithm and sets the integer in the formula to 0. Of course this doesn't make sence when the argument of the logarithm is 0. This is confirmed by setting the Hyperbolic flag. Then I get the answer x = (s1 > 0 ? []_n1 : ln(0) + 2 pi i n2) and in the echo area "Logarithm of zero: 0". -- There is no national science just as there is no national multiplication table; what is national is no longer science. -- Anton Checov