Hi Uwe,
1. Is there any equivalent to org-update-all-dblocks for the source
> blocks?
>
I think you want org-babel-execute-buffer:
Documentation
Call org-babel-execute-src-block on every source block in
the current buffer.
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.
>
Normally, =:results output= should be enough, but there might be some
peculiarities with matlab blocks that change this behavior.
--Diego
