matplotlib-users Mailing List for matplotlib

John Hunter wrote:

>Thanks for the bug reports,
>
>I thing the crash and the shear effect are both part of the same bug
>that arose from a floating point error in converting figure units to
>width and height.  I believe this is a simple fix.  I was able to
>replicate both of the buggy behaviors on my winxp box, and the
>following change fixed both.  Perhaps you and Heiko can test on your
>respective scripts and let me know.
>
>On site-packages/matplotlib/backends/backend_wxagg.py, replace
>FigureCanvasWXAgg.draw with
>
>    def draw(self):
>        """
>        Render the figure using agg
>        """
>        DEBUG_MSG("draw()", 1, self)
>
>        FigureCanvasAgg.draw(self)
>        s = self.tostring_rgb()  
>        w = int(self.renderer.width)
>        h = int(self.renderer.height)
>        image = wxEmptyImage(w,h)
>        image.SetData(s)
>        self.bitmap = image.ConvertToBitmap()
>        self.gui_repaint()
>
>Let me know!
>
>Know if I can just figure out why there is the irritating flicker on
>resizes in win32....
>
>JDH        
>
>
>
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Hello John,

I tested the fix and the problem seems to be gone. I will continue the 
testing and will let you know in case I will find anything else.

Thank you for your fast response and for the great library..

Heiko

>>>>> "Mark" == Mark Howson <ao...@ds...> writes:

    Mark> BTW, the embedding_in_wx4 example (among others) exhibits
    Mark> the same problem for me. I can always reproduce it by
    Mark> launching and resizing the window from small to large,
    Mark> without ever releasing the mouse button. This usually
    Mark> crashes within 10 resizes or so, but as with your
    Mark> description it's intermittent, it can take longer. This is
    Mark> with Windows XP, Python 2.3.4, matplotlib 0.61.0, wxPython
    Mark> 2.5.2.7. It was also present in the last matplotlib and
    Mark> wxPython releases at least. I seem to remember the plain wx
    Mark> frontend also being flaky under this kind of 'abuse', but I
    Mark> can't seem to get that to break now.

    Mark> I also notice that you get a shear effect on some of the
    Mark> resizes (where the plot is drawn as a parallelogram). That's
    Mark> reproducible by shrinking the plot very small, but also
    Mark> occasionally happens at other sizes. I can't be sure whether
    Mark> the size/aspect ratio of the window causes that.

Thanks for the bug reports,

I thing the crash and the shear effect are both part of the same bug
that arose from a floating point error in converting figure units to
width and height.  I believe this is a simple fix.  I was able to
replicate both of the buggy behaviors on my winxp box, and the
following change fixed both.  Perhaps you and Heiko can test on your
respective scripts and let me know.

On site-packages/matplotlib/backends/backend_wxagg.py, replace
FigureCanvasWXAgg.draw with

    def draw(self):
        """
        Render the figure using agg
        """
        DEBUG_MSG("draw()", 1, self)

        FigureCanvasAgg.draw(self)
        s = self.tostring_rgb()  
        w = int(self.renderer.width)
        h = int(self.renderer.height)
        image = wxEmptyImage(w,h)
        image.SetData(s)
        self.bitmap = image.ConvertToBitmap()
        self.gui_repaint()

Let me know!

Know if I can just figure out why there is the irritating flicker on
resizes in win32....

JDH        

Hi,

> I'm getting access violations while resizing the window/splitters of the 
> attached script. The problem is intermittant.

BTW, the embedding_in_wx4 example (among others) exhibits the same 
problem for me. I can always reproduce it by launching and resizing the 
window from small to large, without ever releasing the mouse button. 
This usually crashes within 10 resizes or so, but as with your 
description it's intermittent, it can take longer. This is with Windows 
XP, Python 2.3.4, matplotlib 0.61.0, wxPython 2.5.2.7. It was also 
present in the last matplotlib and wxPython releases at least. I seem to 
remember the plain wx frontend also being flaky under this kind of 
'abuse', but I can't seem to get that to break now.

I also notice that you get a shear effect on some of the resizes (where 
the plot is drawn as a parallelogram). That's reproducible by shrinking 
the plot very small, but also occasionally happens at other sizes. I 
can't be sure whether the size/aspect ratio of the window causes that.