Re: [matplotlib-devel] Bugs in Qt4 backend with the latest PyQt release

[william r. <wil...@gm...>]

Things are more responsive than with python 2.5 and with qt 4.4.3, but the
lag is still noticeable--especially compared to with the addition of the
line.

On Mon, Aug 31, 2009 at 12:05 PM, Darren Dale <dsd...@gm...> wrote:

> I don't understand. With py-2.6, are things more responsive or is
> there an extremely noticeable lag?
>
> On Mon, Aug 31, 2009 at 11:51 AM, william
> ratcliff<wil...@gm...> wrote:
> > Ok, I upgraded to python 2.6, installed mpl 0.99 qt 4.5, and the new pyqt
> > and things are more responsive...However, the difference between having
> that
> > line in and taking it out are the difference between having pan/zoom
> events
> > being extremely responsive and having an extremely noticeable lag.  I've
> > attached a test file from the web which is rather simple.  You can notice
> > the lag if you either try to pan/zoom using the toolbar, or if you try to
> > use the slider to change the sizes of the horizontal bars.
> >
> > Sigh, upgrading everything to 2.6 is going to be a chore...
> >
> >
> > Thanks,
> > William
> >
> > On Mon, Aug 31, 2009 at 11:30 AM, Darren Dale <dsd...@gm...>
> wrote:
> >>
> >> I've been using 2.6. It should be fine on windows now, but I can't
> >> attest to it since I only use windows when I have to test and make
> >> windows installers.
> >>
> >> On Mon, Aug 31, 2009 at 10:02 AM, william
> >> ratcliff<wil...@gm...> wrote:
> >> > Let me try to upgrade to PyQt 4.5--I'm currently using 4.4.3 on vista
> 32
> >> > bit.  Btw. are you using python 2.6 or 2.5 (I ask because I'm still on
> >> > 2.5
> >> > and am wondering if anyone has noticed any difficulties with 2.6).
> >> >
> >> > Cheers,
> >> > Wiliam
> >> >
> >> > On Mon, Aug 31, 2009 at 9:36 AM, Darren Dale <dsd...@gm...>
> wrote:
> >> >>
> >> >> Hi William,
> >> >>
> >> >> On Mon, Aug 31, 2009 at 8:25 AM, william
> >> >> ratcliff<wil...@gm...> wrote:
> >> >> > Hi!  I just installed matplotlib version .99 (windows vista,
> >> >> > python25,
> >> >> > 32bit) and found that
> >> >> > this line was missing:
> >> >> > QtGui.qApp.processEvents()
> >> >> >
> >> >> > Adding it sped the QT4Agg backend back to reasonable speeds--but it
> >> >> > still
> >> >> > seems a bit slow.  Otherwise, I am using the excellent Python(x,y)
> >> >> > 2.1.14
> >> >> > release for my python distribution on this machine.  Could this
> line
> >> >> > be
> >> >> > added back?
> >> >>
> >> >> Unfortunately, no, that line can not be added back in. When that line
> >> >> is in place, the backend attempts to process queued events before it
> >> >> is finished processing the current event. It was leading to segfaults
> >> >> in some cases. processEvents should not be called in the middle of
> >> >> processing an event.
> >> >>
> >> >> I tested the responsiveness of panning and zooming with and without
> >> >> that call to processEvents, on Linux and windows and it looked fine.
> >> >> Maybe its an issue related to a specific Qt version on windows.
> Things
> >> >> looked fine for me with Qt-4.5/PyQt-4.5 on 64bit Vista.
> >> >>
> >> >> Darren
> >> >
> >> >
> >>
> >>
> >>
> >> --
> >> "In our description of nature, the purpose is not to disclose the real
> >> essence of the phenomena but only to track down, so far as it is
> >> possible, relations between the manifold aspects of our experience" -
> >> Niels Bohr
> >>
> >> "It is a bad habit of physicists to take their most successful
> >> abstractions to be real properties of our world." - N. David Mermin
> >>
> >> "Once we have granted that any physical theory is essentially only a
> >> model for the world of experience, we must renounce all hope of
> >> finding anything like the correct theory ... simply because the
> >> totality of experience is never accessible to us." - Hugh Everett III
> >
> >
>
>
>
> --
> "In our description of nature, the purpose is not to disclose the real
> essence of the phenomena but only to track down, so far as it is
> possible, relations between the manifold aspects of our experience" -
> Niels Bohr
>
> "It is a bad habit of physicists to take their most successful
> abstractions to be real properties of our world." - N. David Mermin
>
> "Once we have granted that any physical theory is essentially only a
> model for the world of experience, we must renounce all hope of
> finding anything like the correct theory ... simply because the
> totality of experience is never accessible to us." - Hugh Everett III
>