matplotlib-users Mailing List for matplotlib (Page 2)

Hi,

I'm experiencing a very strange problem with plot_date that I can't
figure out.

    pyplot.plot_date(pylab.date2num(dates),diff,'b-',label='Chained')
    pyplot.show()

dates, naturally, is a list of dates and diff is an array of floats.
With my script, this fails.  But if I interactively enter dates and diff
and then type the above commands, it works with no problems.  Any ideas
or suggestions?

The traceback follows.

Thanks,
Ted

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python2.6/lib-tk/Tkinter.py", line 1413, in __call__
    return self.func(*args)
  File
"/usr/lib/pymodules/python2.6/matplotlib/backends/backend_tkagg.py",
line 245, in resize
    self.show()
  File
"/usr/lib/pymodules/python2.6/matplotlib/backends/backend_tkagg.py",
line 248, in draw
    FigureCanvasAgg.draw(self)
  File
"/usr/lib/pymodules/python2.6/matplotlib/backends/backend_agg.py", line
394, in draw
    self.figure.draw(self.renderer)
  File "/usr/lib/pymodules/python2.6/matplotlib/artist.py", line 55, in
draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/lib/pymodules/python2.6/matplotlib/figure.py", line 798, in
draw
    func(*args)
  File "/usr/lib/pymodules/python2.6/matplotlib/artist.py", line 55, in
draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/lib/pymodules/python2.6/matplotlib/axes.py", line 1946, in draw
    a.draw(renderer)
  File "/usr/lib/pymodules/python2.6/matplotlib/artist.py", line 55, in
draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/lib/pymodules/python2.6/matplotlib/axis.py", line 971, in draw
    tick_tups = [ t for t in self.iter_ticks()]
  File "/usr/lib/pymodules/python2.6/matplotlib/axis.py", line 904, in
iter_ticks
    majorLocs = self.major.locator()
  File "/usr/lib/pymodules/python2.6/matplotlib/dates.py", line 743, in
__call__
    self.refresh()
  File "/usr/lib/pymodules/python2.6/matplotlib/dates.py", line 752, in
refresh
    dmin, dmax = self.viewlim_to_dt()
  File "/usr/lib/pymodules/python2.6/matplotlib/dates.py", line 524, in
viewlim_to_dt
    return num2date(vmin, self.tz), num2date(vmax, self.tz)
  File "/usr/lib/pymodules/python2.6/matplotlib/dates.py", line 289, in
num2date
    if not cbook.iterable(x): return _from_ordinalf(x, tz)
  File "/usr/lib/pymodules/python2.6/matplotlib/dates.py", line 203, in
_from_ordinalf
    dt = datetime.datetime.fromordinal(ix)
ValueError: ordinal must be >= 1

What can be done with the current Matplotlib is to use the offset boxes.
Here is a modified version of a code snippet from

 http://abitofpythonabitofastronomy.blogspot.com/2009/05/mpl-multicolor-text.html

Regards,

-JJ


from matplotlib.offsetbox import HPacker, TextArea, AnnotationBbox

f = figure(1)
ax = f.add_subplot(111)

txt1 = TextArea("A$^3$", textprops=dict(color="r", size=150))
txt2 = TextArea("gb", textprops=dict(color="k", size=150))

txt = HPacker(children=[txt1, txt2],
            align="baseline",
            pad=0, sep=0)

bbox =  AnnotationBbox(txt, xy=(0.5, 0.5),
                       xycoords='data',
                       frameon=False,
                       box_alignment=(0.5, 0.5), # alignment center, center
                       )

ax.add_artist(bbox)

show()





On Wed, Feb 8, 2012 at 7:44 AM, Yann Tambouret <yan...@bu...> wrote:
> Along the lines of Mike's suggestion, I thought this could be done using
> Latex.
>
>
> I posted an answer on SO with an example of doing this, but it seems only to
> work with postscript backend. Other backends override the color with the mpl
> text color setting.
>
> Is there a way to prevent this override? For example don't try to use 'PS'
> backend, and look at hte figure interactively. It defaults to black.
>
> http://stackoverflow.com/a/9185143/717357
>
> -Yann
>
>
>
>
> On Tue, Feb 7, 2012 at 4:46 PM, Paul Ivanov <piv...@gm...> wrote:
>>
>> Benjamin Root, on 2012-02-07 13:46,  wrote:
>> > Also, how deep should this rabbit hole go?  I could imagine one could
>> > want
>> > this for title() and figtitle().  Maybe it would be best to implement
>> > this
>> > at the Text() constructor level?
>>
>> For this reason, I would discourage even implementing such
>> functionality in the core of matplotlib. This functionality doesn't strike
>> me
>> as something that ought to be available everywhere by default - if someone
>> needs it, they can implement it as follows:
>>
>> -----
>> import matplotlib.pyplot as plt
>> from matplotlib import transforms
>>
>> def rainbow_text(x,y,ls,lc,**kw):
>>    """
>>    Take a list of strings ``ls`` and colors ``lc`` and place them next to
>> each
>>    other, with text ls[i] being shown in color lc[i].
>>
>>    This example shows how to do both vertical and horizontal text, and
>> will
>>    pass all keyword arguments to plt.text, so you can set the font size,
>>    family, etc.
>>    """
>>    t = plt.gca().transData
>>    fig = plt.gcf()
>>    plt.show()
>>
>>    #horizontal version
>>    for s,c in zip(ls,lc):
>>        text = plt.text(x,y," "+s+" ",color=c, transform=t, **kw)
>>        text.draw(fig.canvas.get_renderer())
>>        ex = text.get_window_extent()
>>        t = transforms.offset_copy(text._transform, x=ex.width,
>> units='dots')
>>
>>    #vertical version
>>    for s,c in zip(ls,lc):
>>        text = plt.text(x,y," "+s+" ",color=c, transform=t,
>>                rotation=90,va='bottom',ha='center',**kw)
>>        text.draw(fig.canvas.get_renderer())
>>        ex = text.get_window_extent()
>>        t = transforms.offset_copy(text._transform, y=ex.height,
>> units='dots')
>>
>>
>> plt.figure()
>> rainbow_text(0.5,0.5,"all unicorns poop rainbows ! ! !".split(),
>>        ['red', 'orange', 'brown', 'green', 'blue', 'purple', 'black'],
>>        size=40)
>>
>> best,
>> --
>> Paul Ivanov
>> 314 address only used for lists,  off-list direct email at:
>> http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7
>>
>>
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Hi, I have a plot of a time series and I would like to add a single 
extra tick mark and label to the plot in a different color to the 
already existing tick marks. Is this possible??
Thanks,
D

On 2/8/12 2:53 AM, Paul Ivanov wrote:
> Patrick Marsh, on 2012-02-07 13:58,  wrote:
>> As I continue to mature as a Python person, I want to give back
>> explicitly to the community that's given so much to me. The problem
>> is, I don't know how. I'm intimidated by the awesomeness of what I see
>> being done around me that I don't even know where to begin. How does
>> one even begin to learn how to understand the deep intricacies of MPL,
>> Numpy, and Scipy so that I'd begin to develop a comfort level that
>> would allow me to begin to actively contribute? I know pretty much
>> everyone on these listservs, including myself, is busy. (I'm in the
>> midst of a 30-day PhD General Exam, and probably shouldn't even be
>> reading the listservs and/or typing this email! *wink*) But if there
>> are those out there that are willing to take a little time and invest
>> in me, and I'm sure there are others like me, I'd gladly become an
>> active contributor instead of a lurker.
>
> One simple, minimally intimidating way to contribute is by making
> improvements to the documentation. Here's a relevant pitch I just
> made on the IPython lists about how easy, yet valuable such
> improvements can be.
>
> http://mail.scipy.org/pipermail/ipython-user/2012-February/009428.html
>
> Another would be to send the colleagues whom your helping here to
> these lists, that way any effort you put in to help them has a
> good chance of helping others, thanks to search engines and
> archives.
>
> Yet another would be to go through some the active issues on the
> tracker and trying to make a test for them.
>
> Yet another still would be to test the various active pull
> requests - and confirm that the fixes or new functionality they
> provide actually work - look through patches and ask questions -
> we have a lot PRs that get very few eyes or comments on them
> (Last [academic] year, I consciously made an effort to be more
> active on this list, and though I haven't pitched in as much
> lately, perhaps the rest of this year I should focus my efforts
> on incoming PRs)


Another big way we've seen new people contribute to the Sage community 
is to answer questions on the ask.sagemath.org site.  Scipy has a 
similar ask.scipy.org site, but it seems relatively quiet.

Jason

Patrick Marsh, on 2012-02-07 13:58,  wrote:
> As I continue to mature as a Python person, I want to give back
> explicitly to the community that's given so much to me. The problem
> is, I don't know how. I'm intimidated by the awesomeness of what I see
> being done around me that I don't even know where to begin. How does
> one even begin to learn how to understand the deep intricacies of MPL,
> Numpy, and Scipy so that I'd begin to develop a comfort level that
> would allow me to begin to actively contribute? I know pretty much
> everyone on these listservs, including myself, is busy. (I'm in the
> midst of a 30-day PhD General Exam, and probably shouldn't even be
> reading the listservs and/or typing this email! *wink*) But if there
> are those out there that are willing to take a little time and invest
> in me, and I'm sure there are others like me, I'd gladly become an
> active contributor instead of a lurker.

One simple, minimally intimidating way to contribute is by making
improvements to the documentation. Here's a relevant pitch I just
made on the IPython lists about how easy, yet valuable such
improvements can be.

http://mail.scipy.org/pipermail/ipython-user/2012-February/009428.html

Another would be to send the colleagues whom your helping here to
these lists, that way any effort you put in to help them has a
good chance of helping others, thanks to search engines and
archives.

Yet another would be to go through some the active issues on the
tracker and trying to make a test for them. 

Yet another still would be to test the various active pull
requests - and confirm that the fixes or new functionality they
provide actually work - look through patches and ask questions -
we have a lot PRs that get very few eyes or comments on them
(Last [academic] year, I consciously made an effort to be more
active on this list, and though I haven't pitched in as much
lately, perhaps the rest of this year I should focus my efforts
on incoming PRs)
 
> Anyways, I know this email is a tad on the long side, and a little off
> the original topic, so if you're still reading, thanks! This is
> something that's been weighing on me for a few months now, and I
> thought Ben's exultation of the benefits of the community might be a
> good time to open up.

I'm still rather enjoying this whole thread, thanks for opening
up. I got worried how relatively quiet it's been here for a few
months, and glad we're starting to buck that trend.

best,
-- 
Paul Ivanov
314 address only used for lists,  off-list direct email at:
http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7