matplotlib-devel Mailing List for matplotlib

On Monday 24 March 2008 08:09:56 am Michael Droettboom wrote:
> Ted Drain wrote:
> > I've been investigating performance problems we've been having w/ the Qt
> > backends. One problems is that zooming takes forever. I've put a lot of
> > timing loops into the backends to see where things are happening and
> > found a couple of interesting items.
> >
> > The first is that agg seems to get much slower as you zoom in. The agg
> > draw time goes up as the zoom level goes up. These are plots that are
> > completely done w/ the Ellipse patch. Using the Arc patch helps but is
> > about 10% slower when not zooming.
>
> Out of curiosity -- are you using matplotlib 0.91.2, or the SVN trunk?
> The SVN trunk has about 25% faster out-of-bounds vertex removal that
> should improve this.
>
> > The second (and reason for the email), is that the QtAgg backends are
> > redrawing the whole plot twice when zooming w/ the mouse.
>
> It looks like Darren has addressed this part...
That was a different redundant draw() call that Ted reported earlier. I just 
committed this fix, thanks Ted.
Darren

Ted Drain wrote:
> I've been investigating performance problems we've been having w/ the Qt
> backends. One problems is that zooming takes forever. I've put a lot of
> timing loops into the backends to see where things are happening and found a
> couple of interesting items. 
>
> The first is that agg seems to get much slower as you zoom in. The agg draw
> time goes up as the zoom level goes up. These are plots that are completely
> done w/ the Ellipse patch. Using the Arc patch helps but is about 10%
> slower when not zooming. 
> 
Out of curiosity -- are you using matplotlib 0.91.2, or the SVN trunk? 
The SVN trunk has about 25% faster out-of-bounds vertex removal that 
should improve this.
> The second (and reason for the email), is that the QtAgg backends are
> redrawing the whole plot twice when zooming w/ the mouse. 
It looks like Darren has addressed this part...
Cheers,
Mike
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA