** units in R plot
   :PROPERTIES:
   :DATE:     2011-04-21
   :END:
#+begin_src R  :results graphics :file test.png :width 8 :height 8 :res 200 :units cm
  x <- -10:10
  y <- x^2
  plot(x, y, type="l", col="red", lty=1)
#+end_src

#+name:
[[file:test.png]]