From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Schulte Subject: Re: [babel] calc var floating point number error Date: Fri, 20 Jul 2012 08:34:43 -0600 Message-ID: <87txx2ijr0.fsf@gmx.com> References: <1342792553.1277.YahooMailNeo@web29802.mail.ird.yahoo.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="=-=-=" Return-path: Received: from eggs.gnu.org ([208.118.235.92]:39263) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SsEIG-0003Fa-Ub for emacs-orgmode@gnu.org; Fri, 20 Jul 2012 10:35:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SsEIA-0006M6-IH for emacs-orgmode@gnu.org; Fri, 20 Jul 2012 10:35:00 -0400 Received: from mailout-us.gmx.com ([74.208.5.67]:55358) by eggs.gnu.org with smtp (Exim 4.71) (envelope-from ) id 1SsEIA-0006Ls-Bk for emacs-orgmode@gnu.org; Fri, 20 Jul 2012 10:34:54 -0400 In-Reply-To: <1342792553.1277.YahooMailNeo@web29802.mail.ird.yahoo.com> (Giovanni Ridolfi's message of "Fri, 20 Jul 2012 14:55:53 +0100 (BST)") 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: Giovanni Ridolfi Cc: Orgmode --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Giovanni Ridolfi writes: > Hello everyone, > > GNU Emacs 24.1.1 (i386-mingw-nt6.1.7601) of 2012-06-10 on MARVIN > Org-mode version 7.8.11 (eed478ffa @=20 > > > I have a problem with babel and calc. > > I am not able to pass (as variable) floating point numbers.=C2=A0 > > this example works: > > #+BEGIN_SRC calc :var thi=3D20 :var tha=3D90 :var a=3D10 :var rho=3D7854 = :var cp=3D434 :var r=3D5 > ?tha -? (tha - thi) * exp((-3.0*a)/(rho*cp*r)) > #+END_SRC > > #+RESULTS: > : 20.0001232163 > > > However var "r" should be 0.05, but if I use such floating point number I= got an error: > > > #+NAME sphere > #+BEGIN_SRC calc :var thi=3D20 :var tha=3D90 :var a=3D10 :var rho=3D7854 = :var cp=3D434 :var r=3D0.05 > ?tha -? (tha - thi) * exp((-3.0*a)/(rho*cp*r)) > #+END_SRC > > #+RESULTS: > | 19 | Expected a number | > > This behaviour has been reported also in SO > > http://stackoverflow.com/questions/9559221/simple-math-results-in-an-emac= s-org-mode-file-with-babel > The calc internals are truly perplexing. In fact, passing floating point numbers does work as long as division is preformed (see below). When division and floating point numbers are both present, calc inserts a ' into its internal representation. Striping this quote out manually allows the calculation to proceed. The attached patch does this stripping, resulting the in the change of behavior shown below. I suspect that the ' is inserted for some valid reason, so I wouldn't recommend actually applying this patch to Org-mode unless/until someone who is familiar with calc can review it. Here are some calc blocks before and after the patch. --=-=-= Content-Type: text/x-org; charset=utf-8 Content-Disposition: inline; filename=babel-calc.org Content-Transfer-Encoding: quoted-printable #+Title: some calc examples #+BEGIN_SRC calc :var rho=3D7854 :var cp=3D434 :var r=3D0.05 (rho*cp*r) #+END_SRC #+RESULTS: : 170431.8 #+BEGIN_SRC calc :var r=3D0.10 1/r #+END_SRC =E2=86=91 before patch ---------------------------------------------------------------------- =E2=86=93 after patch #+BEGIN_SRC calc :var r=3D0.10 1/r #+END_SRC #+RESULTS: : 10. #+BEGIN_SRC calc :var thi=3D20 :var tha=3D90 :var a=3D10 :var rho=3D7854 :v= ar cp=3D434 :var r=3D0.05 tha - (tha - thi) * exp((-3.0*a)/(rho*cp*r)) #+END_SRC #+RESULTS: : 20.0123205598 --=-=-= Content-Type: text/plain Best, --=-=-= Content-Type: text/x-patch Content-Disposition: inline; filename=0001-strip-quotes-from-calc-internal-representations.patch >From d68c69482013e408c20d0d940abc6bf41b71519c Mon Sep 17 00:00:00 2001 From: Eric Schulte Date: Fri, 20 Jul 2012 08:33:19 -0600 Subject: [PATCH] strip quotes from calc internal representations This allows more calculations to be performed, but at what cost? * lisp/ob-calc.el (org-babel-execute:calc): Strip single quotes from calc internal representations. --- lisp/ob-calc.el | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lisp/ob-calc.el b/lisp/ob-calc.el index f8ad7e3..8f94bcd 100644 --- a/lisp/ob-calc.el +++ b/lisp/ob-calc.el @@ -74,7 +74,7 @@ ((listp res) (error "calc error \"%s\" on input \"%s\"" (cadr res) line)) (t (replace-regexp-in-string - "'\\[" "[" + "'" "" (calc-eval (math-evaluate-expr ;; resolve user variables, calc built in -- 1.7.11.2 --=-=-= Content-Type: text/plain -- Eric Schulte http://cs.unm.edu/~eschulte --=-=-=--