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

[Ben Abbott]

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.

Comments?

Ben