#+name: data
| 1 | 1 |  2 |
| 1 | 2 |  5 |
| 1 | 3 | 10 |
|   |   |    |
| 2 | 1 |  5 |
| 2 | 2 |  8 |
| 2 | 3 | 13 |
|   |   |    |
| 3 | 1 | 10 |
| 3 | 2 | 13 |
| 3 | 3 | 18 |

#+name: clean
#+begin_src sh :var data=data :results file :file /tmp/data.gnuplot
  echo "$data" > /tmp/data.gnuplot
#+end_src

#+begin_src gnuplot :var data=clean(data) :results silent
  splot "$data" u 1:2:3
#+end_src