From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: dieter@duenenhof-wilhelm.de (H. Dieter Wilhelm) Newsgroups: gmane.emacs.help Subject: Re: Getting used to Calc's Radian convention Date: Sat, 13 Sep 2014 09:41:01 +0200 Organization: The Church of Emacs Message-ID: <87vbosvugi.fsf@vsl28t2g.ww011> References: <87bnqklkg8.fsf@debian.uxu> <26301a71-0d4b-4ac5-bf8a-c1deb3f236bd@googlegroups.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1410594111 15374 80.91.229.3 (13 Sep 2014 07:41:51 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 13 Sep 2014 07:41:51 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sat Sep 13 09:41:42 2014 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XShxj-00027F-IC for geh-help-gnu-emacs@m.gmane.org; Sat, 13 Sep 2014 09:41:39 +0200 Original-Received: from localhost ([::1]:48812 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XShxj-0008RX-1r for geh-help-gnu-emacs@m.gmane.org; Sat, 13 Sep 2014 03:41:39 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:60740) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XShxS-0008RC-78 for help-gnu-emacs@gnu.org; Sat, 13 Sep 2014 03:41:29 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XShxJ-00083p-Uv for help-gnu-emacs@gnu.org; Sat, 13 Sep 2014 03:41:22 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:36190) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XShxJ-000839-OH for help-gnu-emacs@gnu.org; Sat, 13 Sep 2014 03:41:13 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XShxH-0001y1-SM for help-gnu-emacs@gnu.org; Sat, 13 Sep 2014 09:41:11 +0200 Original-Received: from p4fd4fb19.dip0.t-ipconnect.de ([79.212.251.25]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 13 Sep 2014 09:41:11 +0200 Original-Received: from dieter by p4fd4fb19.dip0.t-ipconnect.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 13 Sep 2014 09:41:11 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 51 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: p4fd4fb19.dip0.t-ipconnect.de User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3.93 (gnu/linux) Cancel-Lock: sha1:oBpKIA8bFml8sW9QbQ+5XV6YMyM= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:99871 Archived-At: jay.p.belanger@gmail.com writes: >> > Calc's unit convention of revolution per minute (rpm) >> >> > is derived from the angular speed and not from a >> >> > frequency. One does not need to type the factor of `2 >> >> > pi' when calculating, for example, the >> >> > circumferential velocity from the radius and some >> >> > value in rpm. So far so good. >> >> > >> >> > But it has the slight aesthetic drawback that now the >> >> > velocity turns out to be in units of radians. >> >> > >> >> > n <- 1 rpm >> >> > r <- 1 m >> >> > n r -> 2 pi rad m / min > > >> My thoughts are: What?! > > He's referring to Calc (part of Emacs), which can work with units > (such as meters, radians, etc.) Sorry, I made myself not clear and it is basically a question about physics but there seems to be not separate Calc mailing list. > Calc doesn't "know" that the rad probably shouldn't be there; perhaps > there could be a simple way of telling it. As I said I'm happy with the angular notion of Calc's rpm unit but it. Maybe it would help to "degrade" Radian -- it is in Calc a base unit -- to a constant like pi and when converting to base units it simply vanishes when saying `u b' calc-base-units or an additional unit function for converting it to its numerical value? Have fun with Calc -- Best wishes H. Dieter Wilhelm Darmstadt, Germany