Thanks for your suggestion, I solved the problem using:

#+headers: :results output latex
#+begin_src R :session *R* :exports results
...
print(xtable(summary(mypca)))
#+end_src

Regards
Riccardo




2012/2/14 Andreas Leha <andreas.leha@med.uni-goettingen.de>

> Christophe Pouzat <christophe.pouzat@gmail.com> writes:
>
> > Sorry,
> >
> > Checking foo.org
> > (
> http://orgmode.org/w/?p=worg.git;a=blob_plain;f=org-contrib/babel/examples/foo.org;hb=HEAD
> )
> > I got the correct way to do it:
> >
> > #+begin_src R :results output latex :exports results
> >   library(xtable)
> >   xtable(foo, caption = "ANOVA Table", label = "tab:one",
> >       digits = c(0, 0, 2, 0, 2, 3, 3))
> > #+end_src
> >
> > Does it solve your problem?
> >
> > Christophe
> >
> > Riccardo Romoli <ric.romoli@gmail.com> writes:
> >
> >> If I set :export latex when I exports to LaTeX I have only the R code,
> not the
> >> table.
> >>
> >> Best
> >>
> >> 2012/2/14 Christophe Pouzat <christophe.pouzat@gmail.com>
> >>
> >>     Riccardo Romoli <ric.romoli@gmail.com> writes:
> >>
> >>     > Hi, I work with org-babel and R.
> >>     > In the R session I create a table that I have to export to LaTeX.
> >>     > This is the code I use:
> >>     >
> >>     > #+headers: :results latex
> >>     > #+begin_src R :session *R* :exports results
> >>     > .....
> >>     >   print(xtable(summary(mypca)))
> >>     > #+end_src
> >>     >
> >>     > I do not understand why the exported table is delimited by "|":
> >>     >
> >>     > |% latex table generated in R 2.14.1 by xtable 1.6-0 package |
> >>     > | % Tue Feb 14 16:21:48 2012 |
> >>     > | \begin{table}[ht] |
> >>     >   | \begin{center} |
> >>     >     | \begin{tabular}{rrrrrrrrrrrrrrrrr} |
> >>     >       | \hline |
> >>     >       | & PC1 & PC2 & PC3 & PC4 & PC5 & PC6 & PC7 & PC8 & PC9 &
> PC10 &
> >>     >       PC11 & PC12 & PC13 & PC14 & PC15 & PC16 \\ |
> >>     >       | \hline |
> >>     >       | Standard deviation & 3.4693 & 2.8113 & 2.5561 & 2.2668 &
> >>     >       2.0015 & 1.9236 & 1.7287 & 1.6220 & 1.4288 & 1.3456 &
> 1.2596 &
> >>     >       1.2195 & 1.1278 & 1.0778 & 0.8390 & 0.0000 \\ |
> >>     >       | Proportion of Variance & 0.2188 & 0.1437 & 0.1188 &
> 0.0934 &
> >>     >       0.0728 & 0.0673 & 0.0543 & 0.0478 & 0.0371 & 0.0329 &
> 0.0289 &
> >>     >       0.0270 & 0.0231 & 0.0211 & 0.0128 & 0.0000 \\ |
> >>     >       | Cumulative Proportion & 0.2188 & 0.3625 & 0.4813 & 0.5747
> &
> >>     >       0.6476 & 0.7149 & 0.7692 & 0.8170 & 0.8541 & 0.8871 &
> 0.9159 &
> >>     >       0.9429 & 0.9661 & 0.9872 & 1.0000 & 1.0000 \\ |
> >>     >       | \hline |
> >>     >       | \end{tabular} |
> >>     >     | \end{center} |
> >>     >   | \end{table} |
> >>     > | |
> >>     >
> >>     > Should I change some headers settings??
> >>     >
> >>     > Best
> >>     >
> >>
> >>     Hi Riccardo,
> >>
> >>     Try ":exports latex" instead of ":exports results"
> >>
> >>     Christophe
> >>     --
> >>
> >>     Most people are not natural-born statisticians. Left to our own
> >>     devices we are not very good at picking out patterns from a sea of
> >>     noisy data. To put it another way, we are all too good at picking
> out
> >>     non-existent patterns that happen to suit our purposes.
> >>     Bradley Efron & Robert Tibshirani (1993) An Introduction to the
> Bootstrap
> >>
> >>     --
> >>
> >>     Christophe Pouzat
> >>     MAP5 - Mathématiques Appliquées à Paris 5
> >>     CNRS UMR 8145
> >>     45, rue des Saints-Pères
> >>     75006 PARIS
> >>     France
> >>
> >>     tel: +33142863828
> >>     mobile: +33662941034
> >>     web: http://www.biomedicale.univ-paris5.fr/physcerv/C_Pouzat.html
> >>
> >>
>
> Hi Riccardo,
>
> additionally, if you do not want to get too tightly bound to LaTeX, check
> out the ascii-package, e.g.
>
> #+begin_src R :results output org wrap :exports results
>  library(ascii)
>
>  ## from the lm help page:
>  ctl <- c(4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14)
>  trt <- c(4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69)
>  group <- gl(2,10,20, labels=c("Ctl","Trt"))
>  weight <- c(ctl, trt)
>  lm.D9 <- lm(weight ~ group)
>  lm.D90 <- lm(weight ~ group - 1) # omitting intercept
>
>  print(ascii(anova(lm.D9)), type="org")
> #+end_src
>
>
> Cheers,
> Andreas
>
>
>