"errors" when running plot

[Ben Abbott]

On Jun 11, 2009, at 4:46 AM, Francesco Potorti` wrote:

>> One thing is that if you are running a server, superfluous messages  
>> like about
>> X11 not being set can really [...]
>
> I don't fully understand if this is really the same issue, but I  
> have an
> instance of Octave running in a CGI and creating a PNG plot.  Even  
> if I
> start the plotting commands with
>
>   figure("visible","off")
>
> I get
>
>   warning: X11 DISPLAY environment variable not set
>
> in Apache's error log for each invocation of the CGI script.  This
> happens even with Octave 3.2 rc4.

That warning is from Octave's src/display.cc, which determines the  
resolution (dpi) and size of the screen.

The warning is not triggered by using the graphics backend, but is  
part of the initialization process.

Ben