After check out source code of `ob-octave.el`, I found only one places 
used `ans.m`:

```

(defvar org-babel-octave-wrapper-method
   "%s
if ischar(ans), fid = fopen('%s', 'w'); fprintf(fid, '%%s\\n', ans); 
fclose(fid);
else, dlmwrite('%s', ans, '\\t')
end")

```

Might Octave package versions compatition issue or something elseraised 
this error. Based on the error hints, should  be the calling to `ans` is 
wrong. After tesing upper code in Octave REPL, it works fine. that 
weird. The upper variable is just a wrapper around src block `body`for 
saving`ans` to file.

Anyway, hope somebody who knows elisp and Octave can check this out.


On 03/23/2018 08:09 AM, Eric S Fraga wrote:
> On Friday, 23 Mar 2018 at 07:55, stardiviner wrote:
>> I got the following error after executing src block:
>>
>> ```
>>
>> error: invalid call to script /usr/share/octave/4.2.2/m/help/ans.m
> I see the same.  Not sure why this is happening but you can fix it but
> adding any line after the saveas statement that would generate a value,
> e.g. just a "1" will do:
>
> #+begin_src org
>    ,#+begin_src octave :results file :dir "data/images" :file "figure1.png"
>    clf ();
>    surf (peaks);
>    saveas (1, "figure1.png");
>    1
>    ,#+end_src
> #+end_src
>