* [babel] calc var floating point number error @ 2012-07-20 13:55 Giovanni Ridolfi 2012-07-20 14:34 ` Eric Schulte 0 siblings, 1 reply; 3+ messages in thread From: Giovanni Ridolfi @ 2012-07-20 13:55 UTC (permalink / raw) To: Orgmode 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 @ I have a problem with babel and calc. I am not able to pass (as variable) floating point numbers. this example works: #+BEGIN_SRC calc :var thi=20 :var tha=90 :var a=10 :var rho=7854 :var cp=434 :var r=5 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=20 :var tha=90 :var a=10 :var rho=7854 :var cp=434 :var r=0.05 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-emacs-org-mode-file-with-babel cheers, Giovanni ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [babel] calc var floating point number error 2012-07-20 13:55 [babel] calc var floating point number error Giovanni Ridolfi @ 2012-07-20 14:34 ` Eric Schulte 2012-07-25 15:32 ` Eric Schulte 0 siblings, 1 reply; 3+ messages in thread From: Eric Schulte @ 2012-07-20 14:34 UTC (permalink / raw) To: Giovanni Ridolfi; +Cc: Orgmode [-- Attachment #1: Type: text/plain, Size: 1666 bytes --] Giovanni Ridolfi <giovanni.ridolfi@yahoo.it> 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 @ > > > I have a problem with babel and calc. > > I am not able to pass (as variable) floating point numbers. > > this example works: > > #+BEGIN_SRC calc :var thi=20 :var tha=90 :var a=10 :var rho=7854 :var cp=434 :var r=5 > ?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=20 :var tha=90 :var a=10 :var rho=7854 :var cp=434 :var r=0.05 > ?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-emacs-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. [-- Attachment #2: babel-calc.org --] [-- Type: text/x-org, Size: 550 bytes --] #+Title: some calc examples #+BEGIN_SRC calc :var rho=7854 :var cp=434 :var r=0.05 (rho*cp*r) #+END_SRC #+RESULTS: : 170431.8 #+BEGIN_SRC calc :var r=0.10 1/r #+END_SRC ↑ before patch ---------------------------------------------------------------------- ↓ after patch #+BEGIN_SRC calc :var r=0.10 1/r #+END_SRC #+RESULTS: : 10. #+BEGIN_SRC calc :var thi=20 :var tha=90 :var a=10 :var rho=7854 :var cp=434 :var r=0.05 tha - (tha - thi) * exp((-3.0*a)/(rho*cp*r)) #+END_SRC #+RESULTS: : 20.0123205598 [-- Attachment #3: Type: text/plain, Size: 8 bytes --] Best, [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #4: 0001-strip-quotes-from-calc-internal-representations.patch --] [-- Type: text/x-patch, Size: 866 bytes --] From d68c69482013e408c20d0d940abc6bf41b71519c Mon Sep 17 00:00:00 2001 From: Eric Schulte <eric.schulte@gmx.com> 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 [-- Attachment #5: Type: text/plain, Size: 46 bytes --] -- Eric Schulte http://cs.unm.edu/~eschulte ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [babel] calc var floating point number error 2012-07-20 14:34 ` Eric Schulte @ 2012-07-25 15:32 ` Eric Schulte 0 siblings, 0 replies; 3+ messages in thread From: Eric Schulte @ 2012-07-25 15:32 UTC (permalink / raw) To: Giovanni Ridolfi; +Cc: Orgmode Eric Schulte <eric.schulte@gmx.com> writes: > Giovanni Ridolfi <giovanni.ridolfi@yahoo.it> 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 @ >> >> >> I have a problem with babel and calc. >> >> I am not able to pass (as variable) floating point numbers. >> >> this example works: >> >> #+BEGIN_SRC calc :var thi=20 :var tha=90 :var a=10 :var rho=7854 :var cp=434 :var r=5 >> ?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=20 :var tha=90 :var a=10 :var rho=7854 :var cp=434 :var r=0.05 >> ?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-emacs-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. > Looking more closely at the previous behavior (which does remove the ' in some cases), as compared to the patched behavior (which removes the ' in all cases) I have applied this patch after all. It is simpler than the previous behavior, and there is at least one case where it is known to work and the previous behavior is not known to work. Best, -- Eric Schulte http://cs.unm.edu/~eschulte ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-07-25 15:40 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-07-20 13:55 [babel] calc var floating point number error Giovanni Ridolfi 2012-07-20 14:34 ` Eric Schulte 2012-07-25 15:32 ` Eric Schulte
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