matplotlib-users Mailing List for matplotlib

hi all,
i am trying to plot asymmetric yaxis error bars. i have the following code:
import matplotlib.pyplot as plt
a = array([[ 0.5, 1.5],
 [ 0.7, 2.2],
 [ 2.8, 3.1]])
plt.errorbar([1,2,3],[1,2,3],yerr=a)
where each element in the list represents the -yerror, +yerror, like
the documentation for plt.errorbar asks for. when i try to plot this,
i get the following error:
/Library/Python/2.5/site-packages/matplotlib/axes.pyc in vlines(self,
x, ymin, ymax, colors, linestyles, label, **kwargs)
 3271
 3272 verts = [ ((thisx, thisymin), (thisx, thisymax))
-> 3273 for thisx, (thisymin,
thisymax) in zip(x,Y)]
 3274 #print 'creating line collection'
 3275 coll = mcoll.LineCollection(verts, colors=colors,
ValueError: too many values to unpack
any idea what's causing this?
the only way it lets me plot is if i do:
plt.errorbar([1,2,3],[1,2,3],yerr=[a[:, 0], a[:, 1]])
which is not the intended result, since the first column in a is the
-yerror and the second is +yerror. does anyone know how to fix this?
thank you.

On 09/11/2009 10:51 PM, Michael Droettboom wrote:
> The log doesn't show any actual plotting. Did you run the same example
> with debug-annoying turned on? Turning debugging on shouldn't change
> any behavior -- only output more debugging information to the console.
There seems to be something really, really wrong here. As running the
_same_ example with debug-annoying turned on just terminates the
execution at:
backend Agg version v2.2
backend_agg.new_figure_manager
-- 
Regards,
Kamran Riaz Khan.
http://inspirated.com/

davide lasagna <las...@gm...> writes:
> gcc: error trying to exec 'cc1plus': execvp: No such file or directory
Sounds like you don't have a complete g++ install. Since you mentioned
Ubuntu, I suppose the command you need to run is
 sudo apt-get install build-essential g++
and perhaps also
 sudo apt-get build-dep python-matplotlib
to install all the dependencies.
-- 
Jouni K. Seppänen
http://www.iki.fi/jks

Hi everybody,
I have a problem in building matplotlib from svn sources. Here is the output
of the build process.
#######################################################################################
smif1984@ubuntu [14:11:05] ~/cvs/matplotlib :sudo python setupegg.py develop
============================================================================
BUILDING MATPLOTLIB
 matplotlib: 1.0.svn
 python: 2.6.2 (release26-maint, Apr 19 2009, 01:56:41) [GCC
 4.3.3]
 platform: linux2
REQUIRED DEPENDENCIES
 numpy: 1.2.1
 freetype2: 9.20.3
OPTIONAL BACKEND DEPENDENCIES
 libpng: 1.2.27
 Tkinter: no
 * TKAgg requires Tkinter
 wxPython: 2.8.9.1
 * WxAgg extension not required for wxPython >= 2.8
 pkg-config: looking for pygtk-2.0 gtk+-2.0
 * Package pygtk-2.0 was not found in the pkg-config
 * search path. Perhaps you should add the directory
 * containing `pygtk-2.0.pc' to the PKG_CONFIG_PATH
 * environment variable No package 'pygtk-2.0' found
 * You may need to install 'dev' package(s) to
 * provide header files.
 Gtk+: no
 * Could not find Gtk+ headers in any of
 * '/usr/local/include', '/usr/include', '.'
 Mac OS X native: no
 Qt: no
 Qt4: no
 Cairo: 1.4.12
OPTIONAL DATE/TIMEZONE DEPENDENCIES
 datetime: present, version unknown
 dateutil: matplotlib will provide
 pytz: 2008c
OPTIONAL USETEX DEPENDENCIES
 dvipng: 1.11
 ghostscript: 8.64
 latex: 3.141592
 pdftops: 0.10.5
[Edit setup.cfg to suppress the above messages]
============================================================================
pymods ['pylab']
packages ['matplotlib', 'matplotlib.backends', 'matplotlib.projections',
'matplotlib.testing', 'matplotlib.testing.jpl_units', 'matplotlib.tests',
'mpl_toolkits', 'mpl_toolkits.mplot3d', 'mpl_toolkits.axes_grid',
'matplotlib.sphinxext', 'matplotlib.numerix', 'matplotlib.numerix.mlab', '
matplotlib.numerix.ma', 'matplotlib.numerix.linear_algebra',
'matplotlib.numerix.random_array', 'matplotlib.numerix.fft',
'matplotlib.delaunay', 'dateutil', 'dateutil/zoneinfo']
running develop
running egg_info
writing lib/matplotlib.egg-info/PKG-INFO
writing namespace_packages to lib/matplotlib.egg-info/namespace_packages.txt
writing top-level names to lib/matplotlib.egg-info/top_level.txt
writing dependency_links to lib/matplotlib.egg-info/dependency_links.txt
writing entry points to lib/matplotlib.egg-info/entry_points.txt
reading manifest template 'MANIFEST.in'
warning: no files found matching 'MANIFEST'
warning: no files found matching 'examples/data/*'
warning: no files found matching 'lib/mpl_toolkits'
writing manifest file 'lib/matplotlib.egg-info/SOURCES.txt'
running build_ext
building 'matplotlib.ft2font' extension
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall
-Wstrict-prototypes -fPIC -DPY_ARRAYAUNIQUE_SYMBOL=MPL_ARRAY_API
-I/usr/lib/python2.6/dist-packages/numpy/core/include
-I/usr/include/freetype2 -I/usr/local/include -I/usr/include -I.
-I/usr/include/python2.6 -c src/ft2font.cpp -o
build/temp.linux-i686-2.6/src/ft2font.o
gcc: error trying to exec 'cc1plus': execvp: No such file or directory
error: command 'gcc' failed with exit status 1
#############################################################################################
Any help is appreciated.
Cheers
Davide

Thanks, work like a charm.
On Sat, Sep 12, 2009 at 4:06 PM, Gary Ruben <gr...@bi...> wrote:
> gray() sets the default colormap for raster-based plot commands like
> imshow(), matshow() and figimage(). For scatter(), you need to set the
> colors of plot elements invidually. Setting the facecolor in the scatter()
> command will work for the example you tried:
>
> scatter(x,y,s=area, marker='^', facecolor=(.7,.7,.7), c='r')
>
> Gary R.
>
>
> lotrpy wrote:
>
>> Hello, Sorry for my broken english. I copy the source code from
>>
>> http://matplotlib.sourceforge.net/examples/pylab_examples/scatter_demo.html
>> Just Insert one line "gray()" before the last line "show()".
>> But the picture is sitll colorful. not a gray picture.
>> It there somethig I missed. Thanks in advance.
>>
>

gray() sets the default colormap for raster-based plot commands like 
imshow(), matshow() and figimage(). For scatter(), you need to set the 
colors of plot elements invidually. Setting the facecolor in the 
scatter() command will work for the example you tried:
scatter(x,y,s=area, marker='^', facecolor=(.7,.7,.7), c='r')
Gary R.
lotrpy wrote:
> Hello, Sorry for my broken english. I copy the source code from
> http://matplotlib.sourceforge.net/examples/pylab_examples/scatter_demo.html
> 
> Just Insert one line "gray()" before the last line "show()".
> But the picture is sitll colorful. not a gray picture.
> It there somethig I missed. Thanks in advance.