matplotlib-users Mailing List for matplotlib

What it means, specifically, is that one (or more) figure objects still in
memory at the time of exiting the python interpretor are missing the
expected canvas attribute. I see this happen in various backends from time
to time. The best I can figure is that somehow, the destructor for the
figure has already been called (as it should), which should eliminate its
"FigureManager" instance, but for some reason, that figure manager is still
around and its destructor finally tries to destroy the canvas, which is
already gone.
It is really an odd bug, and I am fairly certain my diagnostic isn't quite
right because I never was able to make a SSCE for
testing/debugging/traceback purposes. The closest I was able to get was
with a preliminary version of the animation framework Ryan May and I were
working on a few years back. His code was holding some extra references,
while destroying other objects... it was weird.
Sorry, I don't have any solutions for you. Maybe someone else will.
Ben Root
On Wed, Jun 25, 2014 at 8:29 AM, <kei...@bt...> wrote:
> I am running matplotlib 1.3.1 under Ubuntu 13 and python3.
> Everything works fine, but I get this message every time:
>
> Error in atexit._run_exitfuncs:
> AttributeError: 'FigureManagerGTK3Cairo' object has no attribute 'canvas'
>
> What does it mean, and how do I stop it?
>
> Keith
>
>
>
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It is because the polar projection expects theta to be in radians, not
degrees. This is a somewhat common mistake as the default labelling of a
polar plot is in degrees, and so it tends to confuse new users.
Also, don't forget that your radar data is (most likely) describing
"bearing" (so, 0 azimuth is North rather than East).
Cheers!
Ben Root
On Wed, Jun 25, 2014 at 9:14 AM, Alexander Borghgraef <
ale...@gm...> wrote:
> Hi all,
>
> I'm trying to plot some radar data I'm working on, which is presented as
> a 2048x1440 2D array of ints. This means 2048 azimuth angle values between
> 0° and 360°, and 1440 range increments. Array values represent signal
> return in that angle/range coordinate. Due to hardware problems, some angle
> ranges are missing, there the signal value is zero in the grid.
> The obvious way of plotting this would be a polar grid, so I used a
> pcolormesh, like this:
>
>
>
>
> * import numpy as np import matplotlib.pyplot as plt *
>
> * plt.ion()*
>
>
>
>
> * fig = plt.figure() ax = fig.add_subplot(111, projection='polar')
> theta,rad = np.meshgrid(np.arange(0., 360., 360./scan.shape[0]),
> np.arange(scan.shape[1])) ax.pcolormesh(theta, rad, scan.T) plt.draw()*
>
> I transposed scan because theta and rad are 1440x2048 arrays, where scan
> is a 2048x1440 array.
> The resulting image seemed ok, but there were no gaps, which I knew were
> there, so I ran the same code without the 'polar' option, and put them side
> to side. The result is this:
>
>
> ​In the rectangular plot, there is a gap between around 120° to 160°,
> which should be an empty wedge in the polar plot, but it isn't there. Same
> for the obvious echos at long range between 0° and 50°. OTOH the plot seems
> quite right, with the gating gap around the radar station in the center and
> the stronger echos at short range.
> So I'm a bit baffled as to why this doesn't work the way it should. Does
> anyone here have an explanation?
>
> --
> Alex Borghgraef
>
>
> ------------------------------------------------------------------------------
> Open source business process management suite built on Java and Eclipse
> Turn processes into business applications with Bonita BPM Community Edition
> Quickly connect people, data, and systems into organized workflows
> Winner of BOSSIE, CODIE, OW2 and Gartner awards
> http://p.sf.net/sfu/Bonitasoft
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>

Hi all,
 I'm trying to plot some radar data I'm working on, which is presented as a
2048x1440 2D array of ints. This means 2048 azimuth angle values between 0°
and 360°, and 1440 range increments. Array values represent signal return
in that angle/range coordinate. Due to hardware problems, some angle ranges
are missing, there the signal value is zero in the grid.
 The obvious way of plotting this would be a polar grid, so I used a
pcolormesh, like this:
* import numpy as np import matplotlib.pyplot as plt *
* plt.ion()*
* fig = plt.figure() ax = fig.add_subplot(111, projection='polar')
theta,rad = np.meshgrid(np.arange(0., 360., 360./scan.shape[0]),
np.arange(scan.shape[1])) ax.pcolormesh(theta, rad, scan.T) plt.draw()*
I transposed scan because theta and rad are 1440x2048 arrays, where scan is
a 2048x1440 array.
The resulting image seemed ok, but there were no gaps, which I knew were
there, so I ran the same code without the 'polar' option, and put them side
to side. The result is this:
​In the rectangular plot, there is a gap between around 120° to 160°, which
should be an empty wedge in the polar plot, but it isn't there. Same for
the obvious echos at long range between 0° and 50°. OTOH the plot seems
quite right, with the gating gap around the radar station in the center and
the stronger echos at short range.
 So I'm a bit baffled as to why this doesn't work the way it should. Does
anyone here have an explanation?
-- 
Alex Borghgraef

I am running matplotlib 1.3.1 under Ubuntu 13 and python3.
Everything works fine, but I get this message every time:
 Error in atexit._run_exitfuncs: 
 AttributeError: 'FigureManagerGTK3Cairo' object has no attribute 'canvas'
What does it mean, and how do I stop it?
Keith