[Matlab-emacs-discuss] org mode: execute matlab code and insert it, the matlab shell, matlab live editor, jupiter notebook

[Uwe B. <ou...@ma...>]

Hi

I am not sure whether this mail made to the list, I never saw it. I also
cc this message to John and Eric since they might know more about the
matlab shell.

One of new features in matlab is the matlab live editor, which allows to
mix documentation, matlab code and, most importantly, the results of
executed matlab code. 

It seems that the jupiter notebooks should have a similar feature, but I
have not tried it out.

The question is whether there is a similar solution using emacs. 

And the answer to this is yes, but it is, at the moment, quite slow, at
least with recent matlab releases.

The point is to use org mode.

Org mode is a mayor mode which becomes increasing popular since it ships
with an amazing amount of features.

One of them is to execute code and insert the result in the org buffer,
formatted if wished.
Now matlab is not really supported natively, but John Kitchin posted a
while ago a nice solution on the org mailing list.

(defun org-babel-execute:matlab-john-org (body params) 
  (interactive "P")
  (let* ((current-file (buffer-file-name)) 
	 (code (org-element-property :value (org-element-context)))
	 (result-params (cdr (assoc :result-params params)))
	 m-file
	 md5-hash)
    (with-temp-buffer 
      (insert code)
      (setq md5-hash (md5 (buffer-string))
	    mbuffer (format "*m-%s*" md5-hash)
	    m-file (format "m-%s.m" md5-hash)))
    ;; create the file to run
    (with-temp-file m-file 
      (insert code))
    (let ((results
           (shell-command-to-string
		    (concat
		     "/usr/local/bin/matlab "
		     "-nodesktop <"
;		     "-nodesktop -nojvm -nosplash -nodisplay <"
;		     "-nodesktop -nojvm -nosplash  <"
		     m-file))))
      (delete-file m-file)
      (when results
	;; strip out >>
	(setq results (replace-regexp-in-string ">> " "" results))
	;; remove first 10 lines that are the header.
        ;; matlab license seem to expire soon, so 5 warning lines are added
        ;; change first 10 to first 15 lines
	(setq results (mapconcat 'identity
				 (nthcdr 10 (split-string results "\n"))
				 "\n")))
      (org-babel-result-cond result-params
	results))))

There is a problem with his code, however: It starts every time it is
called the whole matlab engine, making it quite slow.

So I thought of running the emacs matlab shell running and use it
instead. So I came up with the following

(defun org-babel-execute:matlab-john-shell (body params) 
  (interactive "P")
  (let* ((current-file (buffer-file-name)) 
         (code (org-element-property :value (org-element-context)))
         (result-params (cdr (assoc :result-params params))))
    (let ((results
           (matlab-shell-collect-command-output code)))
      (org-babel-result-cond result-params
        results))))



That works, however take the following example
#+begin_src matlab :results output latex :exports results :wrap latex
X=[1,2,3,4,5,6,7];
p=[1/7 1/7 1/7 1/7 1/7 1/7 1/7];
E=X*p';
x2=X.*X;
E2=x2*p';
V=E2-E^2;
disp('\begin{align}')
fprintf('E[X]&=%g\\\\ \n', E)
fprintf('E^2[X]&=%g\\\\\n', E2)
fprintf('V[X]&=%g\n', V)
disp('\end{align}')
disp('\end{align}')
#+end_src

By code only extracts:
#+RESULTS:
#+BEGIN_latex
>> >> p=[1/7 1/7 1/7 1/7 1/7 1/7 1/7];
>> >> E=X*p';
>> >> x2=X.*X;
\begin{align}
E[X]&=4\\ 
E^2[X]&=20\\
V[X]&=4
#+END_latex


But not the last 2 lines of the original matlab code.

Anybody with a better  know of the matlab-shell can explain that to me
please? In order to test the code I should send a bunch of more
functions, which I attach for convince.


Regards

Uwe Brauer