matplotlib-users Mailing List for matplotlib (Page 3)

On Dec 3, 2007 4:57 AM, Dirk Zickermann <dir...@go...> wrote:
> Dear users,
> I would like to generate a colored histogram using a colormap.
> via
> ...
> vals, bins, patchs = pylab.hist(hist_data ,75 ,normed=1)
> ..
> Does anybody know how to assign a colormap to a histogram to find map data
> so that one can find easily data from a 2d map in the histogram?

We need to rewrite histogram to use a PatchCollection, which would be
more efficient and would support colormapping out of the box.  In the
current implementation, you can do it by using the colormap
normalization code and mapping manually on each rectangle.  Here is an
example:

import numpy as n
from pylab import figure, show
import matplotlib.cm as cm
import matplotlib.colors as colors

fig = figure()
ax = fig.add_subplot(111)
Ntotal = 1000
N, bins, patches = ax.hist(n.random.rand(Ntotal), 20)

#I'll color code by height, but you could use any scalar


# we need to normalize the data to 0..1 for the full
# range of the colormap
fracs = N.astype(float)/N.max()
norm = colors.normalize(fracs.min(), fracs.max())

for thisfrac, thispatch in zip(fracs, patches):
    color = cm.jet(norm(thisfrac))
    thispatch.set_facecolor(color)


show()

I'll remove the exe's from SF.  It's been a while since a release, and
I guess I was a little rusty. ;)

- Charlie

On Dec 3, 2007 7:02 PM, John Hunter <jd...@gm...> wrote:
>
> On Dec 3, 2007 5:53 PM, John Hunter <jd...@gm...> wrote:
> > On Dec 3, 2007 5:49 PM, John Hunter <jd...@gm...> wrote:
> >
> > > Charlie, I don't know how you handled this last time, but is there
> > > something in setuptools you have to disable for this build?
> >
> > Well, here's a clue: matplotlib/__init__.py does not exist in this instal
>
> When I copy all the dirs from the 2.5 egg you built into
> site-packages, I get a matplotlib with rcParams and the rest of the
> __init__.py stuff.  Unfortunately, when I try to import pylab, I get
> the dreaded old msvcp71.dll error.  If I recall correctly, we used to
> hack distutils to remove the line that linked with that lib.
>
> JDH
>

On Dec 3, 2007 10:13 AM, John Hunter <jd...@gm...> wrote:

> Sorry for the confusion, I was still on the *old* problem of tkagg
> hanging w/ hist, and was wondering if it was hanging with other plot
> commands too.  Not that you can easily test now w/ the active tcl
> install.

Chris, if you get some time to explore this further, I'd like to see
if we can sort it out.  If you could remove the acive tcl and do a
clean rebuild of mpl, I'd like to verify the hang still exists, and
whether it is hist or all plot commands, and et some version info (eg
what tcl/tk) and see a copy of the mpl build output.  Also, I'd like
to see a run w/ --verbose-debug output.  I find it strange because I
am on the same platform and am not having any troubles (yet) with
tkagg.

JDH

sorry instances of self.plotView.image

On Dec 3, 2007 3:38 PM, Chris Fonnesbeck <lis...@ma...> wrote:
> OK, I'm having a bad backend day (insert joke here).
>
> Since I am on OSX, I decided to switch over to the CocoaAgg backend,
> but it fails when trying to show a histogram, yielding the following
> TypeError:
>
> In [4]: from matplotlib import use
>
> In [5]: use('CocoaAgg')
>
> In [6]: from pylab import hist, show
>
> In [7]: from numpy import random
>
> In [8]: x = random.exponential(2, 1000)
>
> In [9]: hist(x)
> Out[9]:
> (array([545, 230, 117,  59,  18,  15,  11,   1,   3,   1]),
>  array([  2.99606603e-03,   1.52977050e+00,   3.05654494e+00,
>          4.58331937e+00,   6.11009381e+00,   7.63686824e+00,
>          9.16364268e+00,   1.06904171e+01,   1.22171915e+01,
>          1.37439660e+01]),
>  <a list of 10 Patch objects>)
>
> In [10]: show()
> ---------------------------------------------------------------------------
> TypeError                                 Traceback (most recent call last)
>
> /Users/chris/Projects/Occupancy-abundance Manuscript/<ipython console>
> in <module>()
>
> /Library/Python/2.5/site-packages/matplotlib/backends/backend_cocoaagg.py
> in show()
>      44 def show():
>      45     for manager in Gcf.get_all_fig_managers():
> ---> 46         manager.show()
>      47
>      48 def draw_if_interactive():
>
> /Library/Python/2.5/site-packages/matplotlib/backends/backend_cocoaagg.py
> in show(self)
>     203                 mplBundle,
>     204                 False)
> --> 205         NSApplication.sharedApplication().run()
>     206
>     207
>
> /Library/Python/2.5/site-packages/matplotlib/backends/backend_cocoaagg.py
> in startWithBundle_(self, bundle)
>     179     def startWithBundle_(self, bundle):
>     180         #NSApplicationLoad()
> --> 181         if not
> bundle.loadNibFile_externalNameTable_withZone_('Matplotlib.nib', {},
> None):
>     182             print >>sys.stderr, 'Unable to load Matplotlib Cocoa UI!'
>     183             sys.exit()
>
> /Library/Python/2.5/site-packages/matplotlib/backends/backend_cocoaagg.py
> in awakeFromNib(self)
>      79
>      80         self.plotView.setImageFrameStyle_(NSImageFrameGroove)
> ---> 81         self.plotView.image = NSImage.alloc().initWithSize_((0,0))
>      82         self.plotView.setImage_(self.plotView.image)
>      83
>
> TypeError: cannot change a method
>
> --
> Christopher J. Fonnesbeck
> + Fish & Wildlife Research Institute (FWC)
> + 727.235.5570
>
> -------------------------------------------------------------------------
> SF.Net email is sponsored by: The Future of Linux Business White Paper
> from Novell.  From the desktop to the data center, Linux is going
> mainstream.  Let it simplify your IT future.
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> _______________________________________________
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> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

Chris,

This error is due to more stringent error checking in pyobjc2 which
ships with Leopard. I was just preparing a patch to send to the
matplotlib dev guys, but if you replace all instances of self.image
with self._image in backend_cocoaagg.py, things should work. Because
PlotView is an NSImage subclass, it inherits a method named image.
pyobjc previously let you overwrite that method with a python instance
variable, but no longer, hence having to rename the instance variable.

barry

On Dec 3, 2007 3:38 PM, Chris Fonnesbeck <lis...@ma...> wrote:
> OK, I'm having a bad backend day (insert joke here).
>
> Since I am on OSX, I decided to switch over to the CocoaAgg backend,
> but it fails when trying to show a histogram, yielding the following
> TypeError:
>
> In [4]: from matplotlib import use
>
> In [5]: use('CocoaAgg')
>
> In [6]: from pylab import hist, show
>
> In [7]: from numpy import random
>
> In [8]: x = random.exponential(2, 1000)
>
> In [9]: hist(x)
> Out[9]:
> (array([545, 230, 117,  59,  18,  15,  11,   1,   3,   1]),
>  array([  2.99606603e-03,   1.52977050e+00,   3.05654494e+00,
>          4.58331937e+00,   6.11009381e+00,   7.63686824e+00,
>          9.16364268e+00,   1.06904171e+01,   1.22171915e+01,
>          1.37439660e+01]),
>  <a list of 10 Patch objects>)
>
> In [10]: show()
> ---------------------------------------------------------------------------
> TypeError                                 Traceback (most recent call last)
>
> /Users/chris/Projects/Occupancy-abundance Manuscript/<ipython console>
> in <module>()
>
> /Library/Python/2.5/site-packages/matplotlib/backends/backend_cocoaagg.py
> in show()
>      44 def show():
>      45     for manager in Gcf.get_all_fig_managers():
> ---> 46         manager.show()
>      47
>      48 def draw_if_interactive():
>
> /Library/Python/2.5/site-packages/matplotlib/backends/backend_cocoaagg.py
> in show(self)
>     203                 mplBundle,
>     204                 False)
> --> 205         NSApplication.sharedApplication().run()
>     206
>     207
>
> /Library/Python/2.5/site-packages/matplotlib/backends/backend_cocoaagg.py
> in startWithBundle_(self, bundle)
>     179     def startWithBundle_(self, bundle):
>     180         #NSApplicationLoad()
> --> 181         if not
> bundle.loadNibFile_externalNameTable_withZone_('Matplotlib.nib', {},
> None):
>     182             print >>sys.stderr, 'Unable to load Matplotlib Cocoa UI!'
>     183             sys.exit()
>
> /Library/Python/2.5/site-packages/matplotlib/backends/backend_cocoaagg.py
> in awakeFromNib(self)
>      79
>      80         self.plotView.setImageFrameStyle_(NSImageFrameGroove)
> ---> 81         self.plotView.image = NSImage.alloc().initWithSize_((0,0))
>      82         self.plotView.setImage_(self.plotView.image)
>      83
>
> TypeError: cannot change a method
>
> --
> Christopher J. Fonnesbeck
> + Fish & Wildlife Research Institute (FWC)
> + 727.235.5570
>
> -------------------------------------------------------------------------
> SF.Net email is sponsored by: The Future of Linux Business White Paper
> from Novell.  From the desktop to the data center, Linux is going
> mainstream.  Let it simplify your IT future.
> http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

On Dec 3, 2007 5:53 PM, John Hunter <jd...@gm...> wrote:
> On Dec 3, 2007 5:49 PM, John Hunter <jd...@gm...> wrote:
>
> > Charlie, I don't know how you handled this last time, but is there
> > something in setuptools you have to disable for this build?
>
> Well, here's a clue: matplotlib/__init__.py does not exist in this instal

When I copy all the dirs from the 2.5 egg you built into
site-packages, I get a matplotlib with rcParams and the rest of the
__init__.py stuff.  Unfortunately, when I try to import pylab, I get
the dreaded old msvcp71.dll error.  If I recall correctly, we used to
hack distutils to remove the line that linked with that lib.

JDH