[0][babel][R] Undesired conversion of integers to floats in R code block output

[Daniel Drake <silophophe@gmail.com>]

Hi All,

I'm using R in org-mode/babel to analyze data from a psychological
study.  The subjects in this study are identified by nine digit integers
(e.g., 987654321) that I treat as strings (or factors) in my R data
frames.

Tables output by an R code block that contain these subject IDs are
not formatted properly: the subject IDs seem to be treated as numbers
and a decimal point and a trailing zero are appended.  For example,
what should be
|   subj.id |
|-----------|
| 987654321 |
becomes
|     subj.id |
| 987654321.0 |
(I've included real, self-contained code below.)

When I write the data frames directly to a file from within the R code
block (using a write.table function call that mimics the one in
ob-R.el), the integer IDs are preserved; but when code from ob-R.el
writes them out, the values get reformated as floats.

I've noticed that eight digit integers are not modified in the same
way, which makes me wonder if there is a 'digits' threshold I could
modify to prevent this from happening.

I've pretty much ruled out the possibility that this transformation
occurs in R; however I'm not proficient enough in elisp to follow the
operations that happen after the data frame is written to a file in
the org-babel-R-write-object-command.

Any pointers to help me figure this out would be very appreciated!
(I've seen this thread:
http://comments.gmane.org/gmane.emacs.orgmode/31373, but do not know
if the conversion to calc has been made already or if it is the source
of the problem.)

Thanks,
Dan

I'm running:
- Arch Linux (32 bit)
- GNU Emacs 23.4.1
- Org-mode version release_7.8.03-351-g47eb3
- R version 2.14.1 (2011-12-22)

* Test
** table as generated by org-mode/babel
#+name: make
#+begin_src R  :results value  :colnames yes
   temp <- data.frame('A'=c('987654321'),'B'=c('98765432'))
   ## -- this call mimics the one in ob-R.el
write.table(temp,file='test_r.tsv',sep='\t',na='nil',row.names=FALSE,col.names=TRUE,quote=FALSE)
   temp
#+end_src

#+RESULTS: make
|           A |        B |
|-------------+----------|
| 987654321.0 | 98765432 |

** table as generated by R directly
#+name: read
#+begin_src sh  :results output
   cat test_r.tsv
#+end_src

#+RESULTS: read
: A	B
: 987654321	98765432