Problems with LaTeX source block

[Julien Cubizolles <j.cubizolles@free.fr>]

I'm struggling with LaTeX source blocks and am not sure anymore if one
can use the :results file header.

I have a csv file to be processed by tikz to get a png picture displayed
in my org buffer. 

Here is what I tried 

#+NAME: python-tikz
#+header: :results file :file py2tikz_sin.png
#+header: :fit yes :headers '("\\usepackage{tikz,pgfplots}")
#+BEGIN_SRC latex :exports results
  \begin{tikzpicture}
    \begin{axis}
      \addplot  table {sin_py2csv.csv};
    \end{axis}
  \end{tikzpicture}
'py2tikz_sin.png'
#+END_SRC

#+RESULTS: python-tikz
#+BEGIN_LaTeX
[[file:py2tikz_sin.png]]
#+END_LaTeX

Two problems with that: the py2tikz_sin.png file isn't produced (the
latex code is correct though) and I was under the impression that the
:results file header should give a #RESULTS without the LaTeX block
(it's what I get for python blocks anyway).

The data is produced by python (I can get python-babel to work !) and I
could get a png directly through python-babel but latex-babel should be
able to do it, right ?

Julien.