From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Abrahamsen Subject: Re: Unit conversions and symbolic mathematics with Babel Date: Wed, 03 Sep 2014 15:32:55 +0800 Message-ID: <87d2bdb1lk.fsf@ericabrahamsen.net> References: <87vbp5urc4.fsf@vsl28t2g.ww011> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:52416) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XP4zk-0000tx-Er for emacs-orgmode@gnu.org; Wed, 03 Sep 2014 03:28:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XP4ze-0004y9-HF for emacs-orgmode@gnu.org; Wed, 03 Sep 2014 03:28:44 -0400 Received: from plane.gmane.org ([80.91.229.3]:50652) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XP4ze-0004y5-AM for emacs-orgmode@gnu.org; Wed, 03 Sep 2014 03:28:38 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XP4zc-0006vG-6I for emacs-orgmode@gnu.org; Wed, 03 Sep 2014 09:28:36 +0200 Received: from 123.122.44.4 ([123.122.44.4]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 03 Sep 2014 09:28:36 +0200 Received: from eric by 123.122.44.4 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 03 Sep 2014 09:28:36 +0200 List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org Sender: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org To: emacs-orgmode@gnu.org dieter@duenenhof-wilhelm.de (H. Dieter Wilhelm) writes: > Hello Org, > > for some engineering most often I need estimations with unit > conversions, Emacs Calc is perfect for this. > > When it comes to reporting and documentation I'd like to do it with > org-mode, of course. For numerical stuff and visualisation purposes I'm > using already R and TikZ. But for unit conversions and symbolic maths > I'm in a bind when trying to do this with free programs. If you're on a linux of some sort, you probably have the "units" command line program installed. That's sort of the mother of all unit converters, as far as I'm concerned -- you could call out to it and return the results. What do you think? > - R :: Do you have experience with a units packages under the R-project? > What I've seen so far is not so reassuring... > > - Maxima :: I think there is a nice and intuitive units package for > maxima. But this would mean learning an additional tool and mentally > switching between both within one document. > > - Calc :: I'd prefer to do it with Calc but the Babel interface is > (yet?) restricted > > For example, I can define functions and do some unit conversions: > > #+BEGIN_SRC emacs-lisp > (defmath cvun(a b) > (math-convert-units a b)) > #+END_SRC > > > #+RESULTS: > : calcFunc-cvun > > #+BEGIN_SRC calc :var L1 = "5 mm" > cvun( L1, m) > #+END_SRC > > > #+RESULTS: > : 5e-3 m > > But what is missing is to assign variables within a source block > > > #+BEGIN_SRC calc :var L1 = "5 mm" > L2 := cvun( L1, m) > #+END_SRC > > > Unfortunately this is not working. Do you have an idea how to > implement this? > > - Are you using (better) alternatives? > > Thanks for your insights > > Dieter