matplotlib-users Mailing List for matplotlib (Page 2)

Alexandar Hansen wrote:
> Hello,
>
> I've been struggling with this for a while now and have effectively 
> two issues. One, how can I define the range over which hexbin ... 
> bins? And two, how do I change the background color of a plot?

Alexandar:  To change the background color to the lowest value in the 
colormap:

ax = plt.gca()
ax.set_axis_bgcolor(plt.cm.jet(0))


-Jeff
> The latter I thought would be trivial, but nothing I've tried has 
> worked.  Let's take the example:
>
> import numpy as np
> import matplotlib.cm <http://matplotlib.cm> as cm
> import  matplotlib.pyplot as plt
>
> n = 100000
> x = np.random.standard_normal(n)
> y = 2.0 + 3.0 * x + 4.0 * np.random.standard_normal(n)
> #xmin = x.min()
> #xmax = x.max()
> #ymin = y.min()
> #ymax = y.max()
> xmin = 0
> xmax = 10
> ymin = 0
> ymax = 30
>
> plt.hexbin(x,y, cmap=cm.jet)
> #plt.hexbin(x,y, cmap=cm.jet, extent=[xmin, xmax, ymin, ymax])
> plt.axis([xmin, xmax, ymin, ymax])
> plt.title("Hexagon binning")
> cb = plt.colorbar()
> cb.set_label('counts')
>
> plt.show()
>
>
> Let's say i'm only interested in the positive quadrant of the data, so 
> I only want to bin data in the range of 0-10 in x and 0-30 in y.  The 
> first thing I tried was to use the extent option to only bin the 
> specified range of data, but that gives these errors:
>
> [tesla:~/NMR/500-Tupp/IM7][349] HexBin.py
> Traceback (most recent call last):
>   File "HexBin.py", line 28, in <module>
>     plt.hexbin(x,y, cmap=cm.jet, extent=[xmin, xmax, ymin, ymax])
>   File "/usr/lib64/python2.5/site-packages/matplotlib/pyplot.py", line 
> 1920, in hexbin
>     ret =  gca().hexbin(*args, **kwargs)
>   File "/usr/lib64/python2.5/site-packages/matplotlib/axes.py", line 
> 5447, in hexbin
>     collection.update(kwargs)
>   File "/usr/lib64/python2.5/site-packages/matplotlib/artist.py", line 
> 548, in update
>     raise AttributeError('Unknown property %s'%k)
> AttributeError: Unknown property extent
>
>
> After that, I just set the plt.axis range to what I'm interested in. 
> However, the range not binned by hexbin shows up as white, instead of 
> the 0-count blue. I've tried adding facecolor, edgecolor, axisbg, and 
> who knows what else as part of plt.hexbin, plt.axis, and plt.savefig, 
> But most have no consequence on the plot. plt.savefig(myname, 
> facecolor='blue') successfully changed everything blue except the 
> white region within the plot.
>
> So, where am I going wrong? I'm finding myself out of options and 
> would ideally not like to trim or add false points to my data just to 
> get the axis and colors correct.
>
> Best,
> Alex
>
>
> ------------------------------------------------------------------------
>
> ------------------------------------------------------------------------------
>   
> ------------------------------------------------------------------------
>
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>   

Hi,

I just downloaded matplotlib-0.98.5.3.win32-py2.6.exe from sourceforge.

I have an existing Application that works fine with
python       : 2.5.4 final 0
pyGTK        : 2.12.1
GTK+         : 2.14.7
numpy        : 1.2.1
matplotlib   : 0.98.5.2


Now I am trying the same App on
python version    : 2.6.0 final 0
pyGTK version     : 2.12.1
gtk+ version      : 2.16.2
numpy version     : 1.3.0
matplotlib version: 0.98.5.3

I got the following traceback, I'm wondering:
     - Am I looking at changes due to the different matplotlib versions?
    - Are some bits are missing in the downloaded installer ?
     - or is there incompatibility with the newer versions of GTK?

importing matplotlib
Traceback (most recent call last):
  File "C:\SVNproj\FrictionTests2\PyGTKFricPlot.py", line 17, in <module>
    from matplotlib.backends.backend_gtk import FigureCanvasGTK as 
FigureCanvas
  File 
"C:\Python26\Lib\site-packages\matplotlib\backends\backend_gtk.py", line 
25, in <module>
    from matplotlib.backends.backend_gdk import RendererGDK, FigureCanvasGDK
  File 
"C:\Python26\Lib\site-packages\matplotlib\backends\backend_gdk.py", line 
29, in <module>
    from matplotlib.backends._backend_gdk import pixbuf_get_pixels_array
ImportError: No module named _backend_gdk

Thanks for any clues
Steve

As usual, I ended up figuring this out after I sent this question.

The trick was adding the central widget (FigureCanvas) to a QLayout, and
just ignoring the resizeEvent.  So, I just did:

vbox = QVBoxLayout()
vbox.addWidget(self.canvas)
self.setLayout(vbox)

in the custom QWidget which holds the canvas and everything worked fine.  I
also removed the overridden resizeEvent.

BZ

On Wed, Jul 1, 2009 at 1:17 PM, Brian Zambrano <br...@gm...> wrote:

> Hi all,
>
> I'm having a problem with resizing a FigureCanvas using the Qt4 backend
> when the FigureCanvas is used alongside some dock widgets.  What happens is
> that the figure never grows beyond the original size set when the window or
> other dock widgets are expanded.  It's probably easier to look at a
> screenshot taken after I resized (grew) things a bit:
>
> http://brianz.s3.amazonaws.com/mpl_buggy.png
>
> The simple code I used to generate and test this is located here:
>
> http://brianz.s3.amazonaws.com/mpl_qt_buggy.py.txt
>
> To get the FigureCanvas to resize at all, I'm passing the resizeEvent from
> the parent widget down to the FigureCanvas's resizeEvent.
>
> Am I doing something incorrectly here or is this a bug?
>
> Thanks,
> BZ
>