Re: Print Plot Results in all Black plot in file

[Thomas D. Dean]

On 08/03/15 16:33, Markus Appel wrote:
> On 08/04/2015 12:40 AM, Mike Miller wrote:
> > On Mon, Aug 3, 2015 at 15:34:22 -0700, Thomas D. Dean wrote:
> > > When I open sin.png with eog, the axis labels are OK, but, the
> > > plot is just a black square.
> > >
> > > I have something set wrong, but, what?
> >
> > Nope, it's
> >
> > > G N U P L O T Version 5.1 patchlevel 0    last modified
> > > 2015-07-11
> >
> > It's a known bug, see http://savannah.gnu.org/bugs/?42838.
> >
> > I don't remember if there's a viable patch on that bug report yet
> > or what the status is.
> >
> > You can downgrade to gnuplot 4, that works for me. Or use the
> > other toolkits if you can.
>
> I have had this 'black-squares-over-my-plots'-problem as well for some
> time, but could not find the time and motivation (yet) to get to the
> bottom of it.
> As workaround for the time being I suggest trying -dpngcairo or
> -dpdfcairo as print terminal, works for me.
>
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I am struggling thru the code for print.

Is there a global value that can be set to control the output of print.

octave:> z=1:.1:pi;
octave:> plot(z,sin(z));
octave:> print("sin.png","-dpngcairo");

works.

Without -dpngcairo opts.devopt gets set to "-dpng" and print produces a 
black square.

It looks like the opts structure is passed to gnuplot in 
__gnuplot_print__.m.  As a work-around, I patched this file to force 
pngcairo.  Not a solution, just makes lots of scripts work, again.

I don't see any global mechanism to set a default print device.

True?

Tom Dean