Re: na=\"nil\" in ob-R.elo

[Jeremie Juste <jeremiejuste@gmail.com>]

Hello,

Thanks for the feedback

|| On Saturday, 16 Jan 2021 at 00:19, Berry, Charles" via "General discussions about Org-mode. wrote:
> You can use a :post header to customize outputs like this to make them
> more pleasing. Or just use your own
> `org-babel-R-write-object-command'.


As a quick work around you can use

#+name: remove-nil
#+begin_src emacs-lisp :var tbl=""
   (mapcar (lambda (row)
	     (mapcar (lambda (cell)		       
		       (if (equal "nil" cell)
			   ""
			cell))
		     row))
	   tbl)

#+end_src


    
#+BEGIN_SRC R  :results value :colnames yes :post remove-nil[:colnames yes](*this*)
data.frame(A=c(NA,1,1,1,1),B=c(1,2,NA,4,4))
#+end_src

#+RESULTS:
| A | B |
|---+---|
|   | 1 |
| 1 | 2 |
| 1 |   |
| 1 | 4 |
| 1 | 4 |



>> Probably a silly question, but in ob-R.el, what is the reason for
>> setting na=\"nil\" when defining org-babel-R-write-object-command?  Is
>> this an elisp compatibility thing?
>> 
>
> I don't get it either. The value corresponding to the NA becomes a string in emacs-lisp whether \"nil\" or \"\" is used.
> So when passed to elisp via a :post header referencing an emacs-lisp
> src block, its treated as a string.

Thanks Chuck for pointing this out. R users are used to handle NA but in
this particular case where empty string and NA are treated
the same, I'm not sure the nil feature is very useful. If it does not break
anything else I will consider removing it.


Best regards,

-- 
Jeremie Juste