Re: Silent plot(x,y) (3.2 or later bug?)

[Ben Abbott]

On Oct 16, 2009, at 7:10 AM, Ben Abbott wrote:

> On Oct 16, 2009, at 6:14 AM, Tatsuro MATSUOKA wrote:
>
> > Hello
> >
> > I have looked at  codes of gnuplot_drawnow.m and print.m.
> > Initialization of __pixels_per_inch__ is executed in print.m
> >
> > I think that this is a bug.
> >
> > Tentatively, this bug(?) can be avoided by dummy print once for
> > octave 3.2 or later.
> >
> > plot (1:10);print ('dummy.png','-dpng');clf;
> > x=[0:1];
> > for i=[0:100]
> > plot(x,x*i);
> > filename=sprintf("%02d.png",i);
> > drawnow('png',filename);
> > end
> > close;unlink('dummy.png');
> >
> >
> > Side effect: An empty plow window is open during print :-(, but it
> > is no relation for speed
> > please forgive the bug will be fixed.
> >
> > Tatsuro
> >
> > Regards
> >
> > Tatsuro
>
> Yes, it is a bug.
>
> To be consistent with Matlab the default output size is specified in
> inches. When the output is a bitmap, __pixels_per_inch__ is used to do
> the units conversion.
>
> A fix is to edit gnuplot_drawnow.m and replace ...
>
> >             ## Convert to inches using the property set by print().
> >             gnuplot_size = gnuplot_size * get (h, "__pixels_per_inch__");
>
> with ...
>
> >             ## Convert to inches using the property set by print().
> >             try
> >               gnuplot_size = gnuplot_size * get (h, "__pixels_per_inch__");
> >             catch
> >               gnuplot_size = gnuplot_size * get (0, "screenpixelsperinch");
> >             end_try_catch
>
> This would produce an output in the same size as seen on the screen.

Correction, this will not produce an output in the expected size. I'm  
happy to help push a changeset, but don't have time to look at his in  
the necessary detail to produce a proper one myself.

Ben