matplotlib-devel Mailing List for matplotlib

Hi,
I am currently on vacation, so I can ́t be of much help - back 
beginning of next month. It would be useful if
you could try the clabel and ginput demo scripts and send images of 
the resulting figures so that we can determine exactly what things 
work and don ́t work.
Thanks,
David
Mark Bakker <ma...@gm...> ha escrito:
> Hello David and the developers list-
>
> I have had little luck on the mailing list, so sorry for writing you
> directly (David may be on vacation).
>
> I have two problems labeling contour lines in 0.98.3.
>
> First, when I call clabel, it removes all contours that are not labeled
> (because the label doesn't fit on the section of contour, I presume).
> This seems like a bug to me (or a really odd feature). It doesn't do this
> when inline = False, but I don't think it should do it either when inline =
> True
> Easy example:
>
>>>> x,y = meshgrid( linspace(-10,10,50), linspace(-10,10,50) )
>>>> z = log(x**2 + y**2)
>>>> cobj = contour(x,y,z) # Note that there are 8 contours levels (11
> contour sections in all)
>>>> cobj.clabel()
> <a list of 8 text.Text objects>
>>>> draw() # Now only 5 contours are drawn; the ones in the middle are
> removed.
>
> Second, when using the new manual labeling of contour labels (which is
> pretty neat!), how do I end this feature?
> The doc string says: right click, or potentially click both mouse buttons
> together (which already worries me).
> Neither works for me on win32, mpl 0.98.3, TkAgg backend, interactive mode.
> Does anybody have a solution?
>
> Thanks, Mark
>
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On Tue, 2007年11月20日 at 11:15 -1000, Eric Firing wrote:
> Jeff Whitaker wrote:
> > If I draw two images with imshow, then set_zorder for one of them to be 
> > higher than the other, should that one be the one that displays?
> 
> Jeff,
> 
> It is a wart. Images are handled separately from other artists, and 
> always drawn first, either as a composite or in the order in which they 
> were added to the list. Here is the relevant code in the Axes.draw() 
> method:
> 
> if len(self.images)<=1 or renderer.option_image_nocomposite():
> for im in self.images:
> im.draw(renderer)
> else:
> # make a composite image blending alpha
> # list of (mimage.Image, ox, oy)
> 
> 
> mag = renderer.get_image_magnification()
> ims = [(im.make_image(mag),0,0)
> for im in self.images if im.get_visible()]
> 
> 
> im = mimage.from_images(self.bbox.height()*mag,
> self.bbox.width()*mag,
> ims)
> im.is_grayscale = False
> l, b, w, h = self.bbox.get_bounds()
> # composite images need special args so they will not
> # respect z-order for now
> renderer.draw_image(l, b, im, self.bbox)
> 
> Maybe the set_zorder method for images should raise a warning, since it 
> can't do what one might reasonably expect.
> 
> Mike may be able to comment on the prospects for removing this wart at 
> some point in the transforms branch; he is looking at related questions 
> right now.
> 
> Eric
> 
> > 
> > for example, with
> > 
> > from pylab import *
> > delta = 0.025
> > x = y = arange(-3.0, 3.0, delta)
> > X, Y = meshgrid(x, y)
> > Z1 = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
> > Z2 = bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
> > Z = Z2-Z1 # difference of Gaussians
> > im2 = imshow(Z2, interpolation='bilinear', cmap=cm.gray,
> > origin='lower', extent=[-3,3,-3,3])
> > im2.set_zorder(2)
> > im1 = imshow(Z1, interpolation='bilinear', cmap=cm.gray,
> > origin='lower', extent=[-3,3,-3,3])
> > im1.set_zorder(1)
> > show()
> > 
> > I expected Z2 to be plotted, but I actually see Z1. In fact, I always 
> > see the last one that was plotted, regardless of what I set the zorder to.
> > 
> > I'm using the latest SVN, with GTKAgg.
> > 
> > -Jeff
> > 
Any idea if the "wart" can be removed? I tried to use zorder with the
SVN matplotlib (in conjuction with alpha-transparency, it can give a
great way to represent missing data in waterfall diagram)
but without success, image is still always in the back....
I did not use imshow, but NonUniformImage, but I guess the problem is
the same for all AxisImage instances...
BTW, I also submitted a patch to NonUniformImage to allows for bilinear
interpolation on rectangular non-uniform grids. I think the original
code was yours, so maybe you have something to say about the patch ;-)
Best regards,
Greg.

Hi Darren,
2008年8月18日 Darren Dale <dsd...@gm...>:
> Nevermind. It turns out its not exactly poor performance, but for some reason
> the gui events were not getting processed as frequently on windows. Maybe Qt
> changed something in an attempt to optimize performance.
>
> I applied a patch in svn 6043, but its a really simple fix. At the end of
> backend_qt4agg.FigureCanvasQTAgg.draw, after self.update(), add this line:
>
> QtGui.qApp.processEvents()
>
> It seemed to improve things on my windows laptop, but let me know if it fixes
> the problem for you.
Good work Darren, thanks, it works perfectly!
That is great news because I found (and reported) this bug three
months ago, so I was beginning to worry about the future of Qt4
backend.
Now I can consider updating PyQt in Python(x,y).
> I forgot to mention, the svg icons display fine for me with windows xp,
> matplotlib-0.98.
Forget about it, I've just found out that this is related to one of my
own-made packages.
Thanks
Pierre

Hello David and the developers list-
I have had little luck on the mailing list, so sorry for writing you
directly (David may be on vacation).
I have two problems labeling contour lines in 0.98.3.
First, when I call clabel, it removes all contours that are not labeled
(because the label doesn't fit on the section of contour, I presume).
This seems like a bug to me (or a really odd feature). It doesn't do this
when inline = False, but I don't think it should do it either when inline =
True
Easy example:
>>> x,y = meshgrid( linspace(-10,10,50), linspace(-10,10,50) )
>>> z = log(x**2 + y**2)
>>> cobj = contour(x,y,z) # Note that there are 8 contours levels (11
contour sections in all)
>>> cobj.clabel()
<a list of 8 text.Text objects>
>>> draw() # Now only 5 contours are drawn; the ones in the middle are
removed.
Second, when using the new manual labeling of contour labels (which is
pretty neat!), how do I end this feature?
The doc string says: right click, or potentially click both mouse buttons
together (which already worries me).
Neither works for me on win32, mpl 0.98.3, TkAgg backend, interactive mode.
Does anybody have a solution?
Thanks, Mark