org mode with babel source: execute all source blocks, don't export them to latex

[Uwe Brauer <oub@mat.ucm.es>]

Hi 

I have a org file with has a lot source blocks of the form 

#+begin_src matlab  :results output raw :exports code  :eval never-export
close all
N = 3; % number of chebyshev nodes
n = 1; % polytropic index
iters = 1; % iterations
j=[0 1 2 3];
z=cos((pi*j)/3);
y=1-(0.5*(z+1)).^2;
a=n*(8);
a2=eye(3+1)*a;
disp('\begin{align*}')
disp('A_{1,k-1}&=')
disp('\begin{pmatrix}')
fprintf('%g &%g &%g &%g\\\\\n',a2')
disp('\end{pmatrix}=OK\\')
disp('\end{align*}')
#+end_src

#+RESULTS:
\begin{align*}
A_{1,k-1}&=
\begin{pmatrix}
8 &0 &0 &0\\
0 &8 &0 &0\\
0 &0 &8 &0\\
0 &0 &0 &8\\
\end{pmatrix}=OK\\
\end{align*}

Two questions. 

    1. Is there any equivalent to org-update-all-dblocks for the source blocks?

    2. I want to export the org file to latex, in the current setting
       the source blocks are also exported. I tried
       #+begin_src matlab  :results output raw   :eval never-export
       but it did not help. 

Thanks 

Uwe Brauer