** indexing into gnuplot
   :PROPERTIES:
   :DATE:     2009-11-20
   :END:

#+tblname: squares
| 1 |  1 |
| 2 |  4 |
| 3 |  9 |
| 4 | 16 |
| 5 | 25 |
| 6 | 36 |

#+begin_src gnuplot :var data=squares :results silent
plot data using 1:2 with lines
#+end_src

#+tblname: squares-with-sum
|  1 |  1 |
|  2 |  4 |
|  3 |  9 |
|  4 | 16 |
|  5 | 25 |
|  6 | 36 |
|----+----|
| 21 | 91 |

#+begin_src gnuplot :var data=squares-with-sum[0:-3] :results silent
  plot data using 1:2 with lines
#+end_src