** tangle R and load
  :PROPERTIES:
  :tangle:   to-load.r
  :DATE:     2010-08-12
  :END:

evaluate this
#+begin_src emacs-lisp :results silent :tangle no
  (setq org-babel-post-tangle-hook nil)
  (add-hook 'org-babel-post-tangle-hook
            (lambda () (ess-load-file (buffer-file-name))))
#+end_src

then tangle

#+begin_src R :comments yes
x <- 10
#+end_src

#+begin_src R
 y <- 9
#+end_src

#+begin_src R :tangle file2.R
 y <- 9
#+end_src