matplotlib-users Mailing List for matplotlib

Hello, 
I'm creating a web application that will take user input from a javascript
map to give me bounding coordinates (i.e. urcrnrlat, urcrnrlon, llcrnrlat,
llcrnrlon) and possibly a switch for polar projection. Other than that I
have no further information. Which projection is the most suitable to handle
anything from a 'global' plot to a zoom say over a state? I don't see the
zoom being too tight, but global projections are likely. I personally prefer
Equal Area, hence right now I'm working with 'aeqd', but I seem to have
problems if the plot is global with that projection.
Just looking for advice, opinions, and ideally examples if anyone has
created a similar function / module to use in a web environment.
Thanks!
-john
-- 
View this message in context: http://www.nabble.com/dynamic-basemap-tp20121594p20121594.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Hello,
I am getting an error with savefig and pdf when I try to used matplotlib
with latex font rendering (attached below). In etc/matplotlibrc, I set
text.latex.preamble : \usepackage{MinionPro},
\renewcommand{\sfdefault}{Myriad-LF}
It seems that the dviread backend does not find a specific *.vf,
MinionPro-It--lcdfj.vf to be specific,
 file that is not needed in my opinion. Any ideas how to solve that?
Thanks,
David
------------------------------------------------------------------------------------
Traceback (most recent call
last):
 File "niotrode_tipz.py", line 71, in
<module>
p.savefig('niotrode_impedance_plot.pdf')
 File "/usr/lib/python2.5/site-packages/matplotlib/pyplot.py", line 342, in
savefig
 return fig.savefig(*args,
**kwargs)
 File "/usr/lib/python2.5/site-packages/matplotlib/figure.py", line 964, in
savefig
 self.canvas.print_figure(*args,
**kwargs)
 File
"/usr/lib/python2.5/site-packages/matplotlib/backends/backend_qt4agg.py",
line 147, in
print_figure
 FigureCanvasAgg.print_figure(self, *args,
**kwargs)
 File "/usr/lib/python2.5/site-packages/matplotlib/backend_bases.py", line
1310, in print_figure
**kwargs)
 File "/usr/lib/python2.5/site-packages/matplotlib/backend_bases.py", line
1204, in print_pdf
 return pdf.print_pdf(*args,
**kwargs)
 File
"/usr/lib/python2.5/site-packages/matplotlib/backends/backend_pdf.py", line
1864, in print_pdf
self.figure.draw(renderer)
 File "/usr/lib/python2.5/site-packages/matplotlib/figure.py", line 759, in
draw
 for a in self.axes:
a.draw(renderer)
 File "/usr/lib/python2.5/site-packages/matplotlib/axes.py", line 1523, in
draw
a.draw(renderer)
 File "/usr/lib/python2.5/site-packages/matplotlib/axis.py", line 733, in
draw
self.label.draw(renderer)
 File "/usr/lib/python2.5/site-packages/matplotlib/text.py", line 299, in
draw
 bbox, info =
self._get_layout(renderer)
 File "/usr/lib/python2.5/site-packages/matplotlib/text.py", line 199, in
_get_layout
 line, self._fontproperties,
ismath=self.is_math_text(line))
 File
"/usr/lib/python2.5/site-packages/matplotlib/backends/backend_pdf.py", line
1560, in
get_text_width_height_descent
 page =
iter(dvi).next()
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 62, in
__iter__
 have_page =
self._read()
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 119,
in _read
self._dispatch(byte)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 207,
in _dispatch
 self._fnt_def(k, c, s, d, a, l,
n)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 368,
in _fnt_def
 vf =
_vffile(n[-l:])
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 779,
in _vffile
 return _fontfile(texname, Vf, '.vf', _vfcache)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 768,
in _fontfile
 result = class_(filename)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 437,
in __init__
 self._read()
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 119,
in _read
 self._dispatch(byte)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 466,
in _dispatch
 Dvi._dispatch(self, byte)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 207,
in _dispatch
 self._fnt_def(k, c, s, d, a, l, n)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 504,
in _fnt_def
 Dvi._fnt_def(self, k, *args)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 368,
in _fnt_def
 vf = _vffile(n[-l:])
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 779,
in _vffile
 return _fontfile(texname, Vf, '.vf', _vfcache)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 768,
in _fontfile
 result = class_(filename)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 437,
in __init__
 self._read()
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 119,
in _read
 self._dispatch(byte)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 466,
in _dispatch
 Dvi._dispatch(self, byte)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 207,
in _dispatch
 self._fnt_def(k, c, s, d, a, l, n)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 504,
in _fnt_def
 Dvi._fnt_def(self, k, *args)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 370,
in _fnt_def
 self.fonts[k] = DviFont(scale=s, tfm=tfm, texname=n, vf=vf)
 File "/usr/lib/python2.5/site-packages/matplotlib/dviread.py", line 398,
in __init__
 for char in range(0, max(tfm.width)) ]
ValueError: max() arg is an empty sequence

Jesper Larsen wrote:
> Hi mpl users,
>
> I am trying to save a figure to a file like object (a StringIO object)
> and load this object into PIL (Python Imaging Library). The code for
> this is really simple (fig is my figure object):
>
> # This works
> fig.savefig('test.png', format='png')
> im = Image.open('test.png')
>
> # This fails
> imgdata = StringIO.StringIO()
> fig.savefig(imgdata, format='png')
> im = Image.open(imgdata)
>
> File "/home/jl/testfile.py", line 551, in contour
> im = Image.open(imgdata)
> File "/usr/lib/python2.5/site-packages/PIL/Image.py", line 1916, in open
> raise IOError("cannot identify image file")
> IOError: cannot identify image file
> 
You need to "rewind" the StringIO cursor before opening with PIL:
imgdata = StringIO.StringIO()
fig.savefig(imgdata, format='png')
imgdata.seek(0)
im = Image.open(imgdata)
Hope that helps,
Mike
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Hi mpl users,
I am trying to save a figure to a file like object (a StringIO object)
and load this object into PIL (Python Imaging Library). The code for
this is really simple (fig is my figure object):
# This works
fig.savefig('test.png', format='png')
im = Image.open('test.png')
# This fails
imgdata = StringIO.StringIO()
fig.savefig(imgdata, format='png')
im = Image.open(imgdata)
 File "/home/jl/testfile.py", line 551, in contour
 im = Image.open(imgdata)
 File "/usr/lib/python2.5/site-packages/PIL/Image.py", line 1916, in open
 raise IOError("cannot identify image file")
IOError: cannot identify image file
Does anyone know what I am doing wrong? I would really like to avoid
putting the image on disk before opening it in PIL since I am using
the code in a web application where speed is important.
Best regards,
Jesper

On Wed, Oct 22, 2008 at 1:38 PM, Anthony Floyd <ant...@gm...> wrote:
> On Wed, Oct 22, 2008 at 11:00 AM, Michael Droettboom <md...@st...> wrote:
>> Some of the documentation has not yet been reformatted to reST for Sphinx.
>>
>> There is a status page here:
>>
>> http://matplotlib.sourceforge.net/devel/outline.html
>
> Ah, thanks!
>
> [snip]
>
>> As to whether we provide the old docs in parallel -- I'll leave that
>> question to the John or others.
I think it is a good idea to put a copy of the pydoc autogenerated
module docs up, but I won't be able to get to it until next week.
Ditto for the old user's guide.
In the meantime, I've added matplotlib.ticker to the new docs:
 http://matplotlib.sourceforge.net/api/ticker_api.html
JDH

On Wed, Oct 22, 2008 at 11:00 AM, Michael Droettboom <md...@st...> wrote:
> Some of the documentation has not yet been reformatted to reST for Sphinx.
>
> There is a status page here:
>
> http://matplotlib.sourceforge.net/devel/outline.html
Ah, thanks!
[snip]
> As to whether we provide the old docs in parallel -- I'll leave that
> question to the John or others.
I think that it's critical that documentation is not 'lost' (even
temporarily) during the conversion process. Especially for novices or
even for just quick class-checking for advanced users. And while I
suppose people who really need the documentation will run epydoc
against it themselves (guilty) it seems odd to have a reduction of
information on the website.
Just my 0ドル.02. Keep up the good work!
A>

Some of the documentation has not yet been reformatted to reST for Sphinx.
There is a status page here:
http://matplotlib.sourceforge.net/devel/outline.html
(And I'm embarrassed to note that I'm slated to update the ticker 
module... ;)
As to whether we provide the old docs in parallel -- I'll leave that 
question to the John or others.
Mike
Anthony Floyd wrote:
> While I like the redesign (and Sphinx in general), it seems some
> information has gone missing, particularly with regards to the API
> documentation.
>
> For example, ticker.py has a tonne of useful information in the
> docstring about how to set up formatters and tickers. For some reason
> I just cannot find this information on the redesign. The best I get
> is a single line ("class matplotlib.axis.Ticker") on the the Axis
> class API page. On the epydoc based system, it was easy to find.
> Perhaps there's merit in making the API documentation (as spat out by
> epydoc or equivalent) available in parallel to the Sphinx
> documentation?
>
> Cheers,
> A>
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> 
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

While I like the redesign (and Sphinx in general), it seems some
information has gone missing, particularly with regards to the API
documentation.
For example, ticker.py has a tonne of useful information in the
docstring about how to set up formatters and tickers. For some reason
I just cannot find this information on the redesign. The best I get
is a single line ("class matplotlib.axis.Ticker") on the the Axis
class API page. On the epydoc based system, it was easy to find.
Perhaps there's merit in making the API documentation (as spat out by
epydoc or equivalent) available in parallel to the Sphinx
documentation?
Cheers,
A>

Dear Mike,
thanks a lot for the information.
Best wishes,
Federico
Michael Droettboom wrote:
> Unfortunately, clip paths are not implemented for the Agg backend. 
> Other backends (Ps, Pdf, Svg) may work, but I haven't tried that in a 
> while.
>
> I've spent a few tries trying to come up with the magic Agg 
> incantation to make this work. It's not really documented in Agg, but 
> it should theoretically be possible. It would take someone probably 
> to dig through the Agg source code and figure it out. Any volunteers? ;)
>
> Cheers,
> Mike
>
> Federico Milano wrote:
>> Dear All,
>>
>> I am a new user of python and of matplotlib, so, please excuse me if I
>> am asking a trivial question.
>>
>> I am trying to use the funciton imshow to plot a temperature map of the
>> voltage levels of an electrical grid. After creating the grid data
>> using "meshgrid" and "griddata" functions, "imshow" works nicely and
>> fills up the whoe axes box.
>>
>> Since, I also have the border line of the electrical grid (in the form
>> of a closed polygon coordinates), my next step is to clip the
>> temperature map using this polygon as a patch. Thus, I have created a
>> Path instance with the polygon coordinates, subsequently, a PathPatch
>> instance, say "patch".
>>
>> Finally, I call the imshow function using the Artist options
>> "clip_on=True" and "clip_path=patch". I was expecting that imshow would
>> have filed up only the region inside the polygon, but imshow is still
>> mapping the full figure axis box, i.e., the plots with and without the
>> clip_path option are identical.
>>
>> What am I missing or doing wrong?
>>
>> Thank you very much in advance for any help,
>>
>> Best wishes,
>>
>> Federico
>>
>>
>>
>> ------------------------------------------------------------------------- 
>>
>> This SF.Net email is sponsored by the Moblin Your Move Developer's 
>> challenge
>> Build the coolest Linux based applications with Moblin SDK & win 
>> great prizes
>> Grand prize is a trip for two to an Open Source event anywhere in the 
>> world
>> http://moblin-contest.org/redirect.php?banner_id=100&url=/
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>> 
>

Unfortunately, clip paths are not implemented for the Agg backend. 
Other backends (Ps, Pdf, Svg) may work, but I haven't tried that in a while.
I've spent a few tries trying to come up with the magic Agg incantation 
to make this work. It's not really documented in Agg, but it should 
theoretically be possible. It would take someone probably to dig 
through the Agg source code and figure it out. Any volunteers? ;)
Cheers,
Mike
Federico Milano wrote:
> Dear All,
>
> I am a new user of python and of matplotlib, so, please excuse me if I
> am asking a trivial question.
>
> I am trying to use the funciton imshow to plot a temperature map of the
> voltage levels of an electrical grid. After creating the grid data
> using "meshgrid" and "griddata" functions, "imshow" works nicely and
> fills up the whoe axes box.
>
> Since, I also have the border line of the electrical grid (in the form
> of a closed polygon coordinates), my next step is to clip the
> temperature map using this polygon as a patch. Thus, I have created a
> Path instance with the polygon coordinates, subsequently, a PathPatch
> instance, say "patch".
>
> Finally, I call the imshow function using the Artist options
> "clip_on=True" and "clip_path=patch". I was expecting that imshow would
> have filed up only the region inside the polygon, but imshow is still
> mapping the full figure axis box, i.e., the plots with and without the
> clip_path option are identical.
>
> What am I missing or doing wrong?
>
> Thank you very much in advance for any help,
>
> Best wishes,
>
> Federico
>
>
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> 
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Dear All,
I am a new user of python and of matplotlib, so, please excuse me if I
am asking a trivial question.
I am trying to use the funciton imshow to plot a temperature map of the
voltage levels of an electrical grid. After creating the grid data
using "meshgrid" and "griddata" functions, "imshow" works nicely and
fills up the whoe axes box.
Since, I also have the border line of the electrical grid (in the form
of a closed polygon coordinates), my next step is to clip the
temperature map using this polygon as a patch. Thus, I have created a
Path instance with the polygon coordinates, subsequently, a PathPatch
instance, say "patch".
Finally, I call the imshow function using the Artist options
"clip_on=True" and "clip_path=patch". I was expecting that imshow would
have filed up only the region inside the polygon, but imshow is still
mapping the full figure axis box, i.e., the plots with and without the
clip_path option are identical.
What am I missing or doing wrong?
Thank you very much in advance for any help,
Best wishes,
Federico

On Wed, Oct 22, 2008 at 7:27 AM, Jeffrey Fogel
<mat...@je...> wrote:
> I've having a problem creating multiple x-axis and I'm hoping someone
> here will be able to help me. I have two directly correlated values
> (z and N) that I am using as the independent variables. What I would
> like to do is plot my data vs. N, but then show the corresponding z
> values on the top axis (there is a 1-to-1 correspondence between every
> z and N value). I have tried twiny, but this requires me to plot the
> line again and, since the z and N values are scaled differently, I end
> up with 2 lines that don't match up.
>
Hi Jeffrey,
Are you adverse to drawing two lines? If you use the 'twiny'
approach, you can simply manually set the top-axis limits to
correspond to what you need:
In [2]: plot([1,2,3], [4,5,6])
Out[2]: [<matplotlib.lines.Line2D instance at 0x91abd8>]
In [3]: ax1 = gca()
In [4]: ax2 = gcf().add_axes(ax1.get_position(), sharey=ax1, frameon=False)
In [5]: ax2.xaxis.tick_top()
In [6]: plot([1.3, 2.6, 3.9],[4,5,6])
Out[6]: [<matplotlib.lines.Line2D instance at 0x1b76ab8>]
In [7]: ax2.set_xlim([1.3,3.9])
Out[7]: (1.3, 3.8999999999999999)
In [8]: draw()
Cheers,
A>

Mike Bauer wrote:
> Jeff,
>
> Using Python 2.6 results in the following Deprecation Warnings:
>
> /usr/local/lib/python2.6/site-packages/pytz/tzinfo.py:5: 
> DeprecationWarning: the sets module is deprecated
> from sets import Set
> /usr/local/lib/python2.6/site-packages/httplib2/__init__.py:29: 
> DeprecationWarning: the md5 module is deprecated; use hashlib instead
> import md5
> /usr/local/lib/python2.6/site-packages/httplib2/__init__.py:44: 
> DeprecationWarning: the sha module is deprecated; use the hashlib 
> module instead
> import sha
>
> Don't know if this is a problem.
Mike: No, that's not a problem. I've fixed the httplib2 warnings in SVN.
>
> I moved the basemap instance call outside the loop and the problem is 
> greatly reduced; although my memory usage still linearly increases but 
> by say 0.5 Gb instead of 6 Gb.
> I can live with that. Python2.5 lacks this increase as you expected.
>
> I ran trunk/matplotlib/unit//memleak_hawaii.py with python2.6:
> Average memory consumed per loop: 0.4428k bytes
>
> /Same call from python2.5:
> Average memory consumed per loop: 0.5672k bytes
>
> Seems basemap is needed to the memory leak.
>
> Mike
Can you send me the script you used to detect the leak?
-Jeff
>
> On Tue, Oct 21, 2008 at 5:36 PM, Jeff Whitaker <js...@fa... 
> <mailto:js...@fa...>> wrote:
>
> Mike Bauer wrote:
>
> I've been testing matplotlib and basemap (0.98.x and 0.99.x
> via svn source) and python 2.6 (via svn) on ubuntu 8.04 (AMD-64).
>
> I noticed that calling basemap in a loop results in a fairly
> steep linear increase in memory use; I burn though 6 Gb in a
> minute.
>
> Putting a loop in plotmap.py from the provided examples does
> this as well, so I don't think it's something I'm doing.
>
> Any ideas?
>
> Thanks.
>
> Mike
>
> P.S. Note that I'd like to use python 2.6 for the
> multiprocessing module (not in use in this script as of yet).
> My base install of python 2.5 with matplotlib and basemap
> (0.98.3 and 0.99.1 via sourceforge sourse) works fine.
>
>
> Mike: Note that you don't actually need to recreate the basemap
> instance each time through the loop (since the map projection
> region is not changing).
> AFAIK there are no serious memory leaks in basemap with python 2.5
> - so if you can provide an example that triggers one I'd like to
> see it.
> Sounds like it might only be occurring with python 2.6?
>
> -Jeff
>
> -- 
> Jeffrey S. Whitaker Phone : (303)497-6313
> Meteorologist FAX : (303)497-6449
> NOAA/OAR/PSD R/PSD1 Email : Jef...@no...
> <mailto:Jef...@no...>
> 325 Broadway Office : Skaggs Research Cntr 1D-113
> Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg
>
>
-- 
Jeffrey S. Whitaker Phone : (303)497-6313
Meteorologist FAX : (303)497-6449
NOAA/OAR/PSD R/PSD1 Email : Jef...@no...
325 Broadway Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg

I've having a problem creating multiple x-axis and I'm hoping someone
here will be able to help me. I have two directly correlated values
(z and N) that I am using as the independent variables. What I would
like to do is plot my data vs. N, but then show the corresponding z
values on the top axis (there is a 1-to-1 correspondence between every
z and N value). I have tried twiny, but this requires me to plot the
line again and, since the z and N values are scaled differently, I end
up with 2 lines that don't match up.
I hope that was understandable. Any advice? Thanks.
-Jeffrey

Hello list,
I observe a small bug in slider_demo.py, which lives in the svn 
folder /examples/widgets and can be accessed via
http://matplotlib.sourceforge.net/_static/plot_directive/mpl_examples/widgets/slider_demo.py .
The hovercolor for grey needs to be a string instead of a float. I attached a 
small patch for simplicity.
regards
Matthias
ps: Nevertheless the new webpage looks very nice and searching is well 
supported.

Hello,
Are the docs for the maintenence release (0.91) available online? I cannot
find them online anymore and it would be useful for people who are still
using it.
thanks
Bartek
P.S. I'm new to the list so it's a good opportunity to thank everyone
involved for making matplotlib. It's really a good piece of software.
-- 
Bartek Wilczynski
==================
Postdoctoral fellow
EMBL, Furlong group
Meyerhoffstrasse 1,
69012 Heidelberg,
Germany
tel: +49 6221 387 8433

You need full administrator rights for pylab to work - power user status is
not enough.
got the following error when I tried to call in
"From pylab import *" :
 Traceback (most recent call last):
 File "<pyshell#0>", line 1, in <module>
 from pylab import *
 File "C:\Python25\Lib\site-packages\pylab.py", line 1, in <module>
 from matplotlib.pylab import *
 File "C:\Python25\lib\site-packages\matplotlib\__init__.py", line 677, in
<module>
 rcParams = rc_params()
 File "C:\Python25\lib\site-packages\matplotlib\__init__.py", line 598, in
rc_params
 fname = matplotlib_fname()
 File "C:\Python25\lib\site-packages\matplotlib\__init__.py", line 548, in
matplotlib_fname
 fname = os.path.join(get_configdir(), 'matplotlibrc')
 File "C:\Python25\lib\site-packages\matplotlib\__init__.py", line 242, in
wrapper
 ret = func(*args, **kwargs)
 File "C:\Python25\lib\site-packages\matplotlib\__init__.py", line 438, in
_get_configdir
 raise RuntimeError("Failed to create %s/.matplotlib; consider setting
MPLCONFIGDIR to a writable directory for matplotlib configuration data"%h)
RuntimeError: Failed to create C:\/.matplotlib; consider setting
MPLCONFIGDIR to a writable directory for matplotlib configuration data
-- 
View this message in context: http://www.nabble.com/Can%27t-Import-Pylab-on-XP---runtime-error.-tp20034693p20108537.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Dear mpl developers -
I recall there has been some discussion in the past on developing the
ability to have a widget for entering data. I also recall that was not an
easy thing to do.
What's the current status? Doable?
Thanks, Mark
ps. The new website is really very nice!