Re: babel, matlab export plot to png fails

["Berry, Charles" <ccberry@ucsd.edu>]

> On Aug 15, 2017, at 2:12 AM, Neil Jerram <neil@ossau.homelinux.net> wrote:
> 
> On 13/08/17 10:33, Uwe Brauer wrote:
>> Hi
>> 
>> I would like to execute some matlab code in org file (using GNU emacs 26
>> and the git version of org mode) and save the result of the plot command
>> in a png file, so I tried
>> 
>> #+begin_src matlab :session :exports both :file testplot.png
>> t=[0:0.1:1];
>> y=sin(t);
>> plot(t,y)
>> print -dpng  testplot.png
>> #+end_src
>> 
>> And also
>> #+begin_src matlab :results output latex :exports results  :file testplot.png
>> t=[0:0.1:1];
>> y=sin(t);
>> plot(t,y)
>> print -dpng  testplot.png
>> #+end_src
>> 

I do not have matlab, but looking at the code in ob-matlab.el and ob-octave.el, it seems that the usual header args should do:

:  :results graphics :file testplot.png

and delete the print statement in the last line.

I do not see this documented in (info "(org) results") as it is language specific. Following the page that (info "(org) Languages") points to leads to 

	`http://orgmode.org/worg/org-contrib/babel/languages/ob-doc-octave-matlab.html

which looks like  it is out-of-date. (Specifically, org-babel-execute:matlab calls org-babel-execute:octave which *now* sets the result to nil and places the print statement as needed when ~:results graphics~ is specified, but the example will fail under the new regime.)

Maybe a link to the Languages worg page should be added in (info "(org) results") and (sigh) maybe the worg pages can be updated to include revision dates?

HTH,

Chuck