matplotlib-users — Discussion related to using matplotlib

Re: [Matplotlib-users] Plotting from datafile

[Steven B. <bo...@ph...>]

Hey Sayan,

Here is the manual page:

http://docs.scipy.org/doc/numpy/reference/generated/numpy.genfromtxt.html

It works (basically) the same as loadtxt, but it is more flexible when 
there are holes in your data.

Good luck.

Steven

On Wed Mar 27 10:07:10 2013, Sayan Chatterjee wrote:
> Hi Steven,
>
> I am a newbie to Python and hence Matplotlib. I cannot get your point
> properly. Could you please redirect me to a page where the usage is
> demonstrated?
>
> As I can see, you're a doctoral student in Physics, it might be
> worthwhile to tell you that I'm trying to code a  Zeldovich
> Approximation for a simple sinusoidal potential and want to make it
> evolve with varying scale factor and make an animation of it.
>
> Cheers,
> Sayan
>
>
> On 27 March 2013 19:58, Steven Boada <bo...@ph...
> <mailto:bo...@ph...>> wrote:
>
>     Another, slightly more flexible, option is the genfromtxt
>     function, also in numpy. Normally you should try genfromtxt after
>     loadtxt doesn't work. Or, that is my normal method.
>
>     Steven
>
>
>     On Wed Mar 27 07:16:45 2013, Sayan Chatterjee wrote:
>
>         Thank you very much for your prompt reply.
>
>         Florian,  your reply seems to be the answer to my question.
>         I'll try
>         it out. If can't figure out,I'll get back to you.
>
>
>         On 27 March 2013 15:37, Florian M. Wagner
>         <wag...@st... <mailto:wag...@st...>
>         <mailto:wag...@st....__ch
>         <mailto:wag...@st...>>> wrote:
>
>             Hey Sayan,
>
>             for reading in simple ASCII-Files containing your two
>         arrays you
>             should have a look at the numpy.loadtxt function.
>
>             Scatter plots in matplotlib are then easily created as
>         shown here
>         http://matplotlib.org/__examples/pylab_examples/__scatter_demo.html
>         <http://matplotlib.org/examples/pylab_examples/scatter_demo.html>
>
>             For your purpose you can do something like:
>
>                 import os
>                 import numpy as np
>                 import matplotlib.pyplot as plt
>
>                 for file in os.path.listdir():
>                     x, y = np.loadtxt(file, unpack=True)
>                     plt.scatter(x,y)
>                     plt.savefig(file + '.png')
>
>             Cheers,
>
>             Florian
>
>
>             Am 27.03.2013 09:32, schrieb Sayan Chatterjee:
>
>                 Dear All,
>
>                 I'm new to Matplotlib. It might be a silly question,
>             how does one
>                 plot data(not functions) in Matplotlib.
>
>                 How:
>                 1)Two arrays (X and Y) can be plotted in a scatter
>             diagram?
>
>                 2) or a number of data files can used to produce
>             different plots
>                 having different(sequential) name?
>
>                 Thanks in anticipation.
>                 Regards,
>                 Sayan
>
>                 --
>
>
>
>             ------------------------------__------------------------------__--------------
>                 *Sayan  Chatterjee*
>
>                 Dept. of Physics and Meteorology
>                 IIT Kharagpur
>                 Lal Bahadur Shastry Hall of Residence
>                 Room AB 205
>                 Mob: +91 9874513565
>                 blog: www.blissprofound.blogspot.com
>             <http://www.blissprofound.blogspot.com>
>                 <http://www.blissprofound.__blogspot.com
>             <http://www.blissprofound.blogspot.com>>
>
>                 Volunteer , Padakshep
>             www.padakshep.org <http://www.padakshep.org>
>             <http://www.padakshep.org>
>
>
>
>
>             ------------------------------__------------------------------__------------------
>                 Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>                 Rise to greatness in Intel's independent game demo
>             contest.
>                 Compete for recognition, cash, and the chance to get
>             your game
>                 on Steam. $5K grand prize plus 10 genre and skill prizes.
>                 Submit your demo by
>             6/6/13.http://p.sf.net/sfu/__intel_levelupd2d
>             <http://p.sf.net/sfu/intel_levelupd2d>
>
>
>                 _________________________________________________
>                 Matplotlib-users mailing list
>             Matplotlib-users@lists.__sourceforge.net
>             <mailto:Mat...@li...>
>              <mailto:Matplotlib-users@__lists.sourceforge.net
>             <mailto:Mat...@li...>>
>             https://lists.sourceforge.net/__lists/listinfo/matplotlib-__users
>             <https://lists.sourceforge.net/lists/listinfo/matplotlib-users>
>
>
>
>
>         ------------------------------__------------------------------__------------------
>             Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>             Rise to greatness in Intel's independent game demo contest.
>             Compete for recognition, cash, and the chance to get your game
>             on Steam. $5K grand prize plus 10 genre and skill prizes.
>             Submit your demo by 6/6/13.
>         http://p.sf.net/sfu/intel___levelupd2d
>         <http://p.sf.net/sfu/intel_levelupd2d>
>             _________________________________________________
>             Matplotlib-users mailing list
>         Matplotlib-users@lists.__sourceforge.net
>         <mailto:Mat...@li...>
>             <mailto:Matplotlib-users@__lists.sourceforge.net
>         <mailto:Mat...@li...>>
>         https://lists.sourceforge.net/__lists/listinfo/matplotlib-__users
>         <https://lists.sourceforge.net/lists/listinfo/matplotlib-users>
>
>
>
>
>         --
>
>
>         ------------------------------__------------------------------__--------------
>         *Sayan  Chatterjee*
>
>         Dept. of Physics and Meteorology
>         IIT Kharagpur
>         Lal Bahadur Shastry Hall of Residence
>         Room AB 205
>         Mob: +91 9874513565
>         blog: www.blissprofound.blogspot.com
>         <http://www.blissprofound.blogspot.com>
>         <http://www.blissprofound.__blogspot.com
>         <http://www.blissprofound.blogspot.com>>
>
>         Volunteer , Padakshep
>         www.padakshep.org <http://www.padakshep.org>
>         <http://www.padakshep.org>
>
>
>
>         ------------------------------__------------------------------__------------------
>         Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>         Rise to greatness in Intel's independent game demo contest.
>         Compete for recognition, cash, and the chance to get your game
>         on Steam. $5K grand prize plus 10 genre and skill prizes.
>         Submit your demo by 6/6/13.
>         http://p.sf.net/sfu/intel___levelupd2d
>         <http://p.sf.net/sfu/intel_levelupd2d>
>
>
>         _________________________________________________
>         Matplotlib-users mailing list
>         Matplotlib-users@lists.__sourceforge.net
>         <mailto:Mat...@li...>
>         https://lists.sourceforge.net/__lists/listinfo/matplotlib-__users
>         <https://lists.sourceforge.net/lists/listinfo/matplotlib-users>
>
>
>     --
>
>     Steven Boada
>
>     Doctoral Student
>     Dept of Physics and Astronomy
>     Texas A&M University
>     bo...@ph... <mailto:bo...@ph...>
>
>
>
>
> --
>
>
> --------------------------------------------------------------------------
> *Sayan  Chatterjee*
> Dept. of Physics and Meteorology
> IIT Kharagpur
> Lal Bahadur Shastry Hall of Residence
> Room AB 205
> Mob: +91 9874513565
> blog: www.blissprofound.blogspot.com
> <http://www.blissprofound.blogspot.com>
>
> Volunteer , Padakshep
> www.padakshep.org <http://www.padakshep.org>

--

Steven Boada

Doctoral Student
Dept of Physics and Astronomy
Texas A&M University
bo...@ph...

[Matplotlib-users] problem with axhline and yscale

[Steven B. <bo...@ph...>]

Hey List,

If you create a horizontal line, and then adjust the size of the figure, 
or axis limits the horizontal line does not move with everything else...

To reproduce in ipython -pylab:

axhline(5)
yscale('log')
ylim(0.5,30)

The line stays where it started and is not moved when the plot is redrawn.

This was discussed here (back in 2008!!!!!):

http://matplotlib.1069221.n5.nabble.com/transforms-bug-axhline-with-log-y-scale-td35548.html

Then... when you save the figure, the position of the horizontal line 
does *NOT* match the position you see when the figure is shown...

savefig('test.eps')

Am I missing something?

Steven

-- 

Steven Boada

Doctoral Student
Dept of Physics and Astronomy
Texas A&M University
bo...@ph...

[Matplotlib-users] difficult LaTeX formula for rendering

[Ilias M. <Mir...@um...>]

Dear experts,

in our sphinx-based project documentation (www.diracprogram.org) we have a complicated latex math formula, which is not rendered:

/usr/lib/pymodules/python2.7/matplotlib/sphinxext/mathmpl.py:56: Warning: Could not render math expression $i \hbar \frac{\partial}{\partial t} \left( \begin{array}{c}\Psi^L \\\Psi^S \end{array} \right) = c  \left( \begin{array}{c}(\vec{\sigma} \cdot \vec{\pi}) \Psi^S \\(\vec{\sigma} \cdot \vec{\pi}) \Psi^L \end{array} \right)+ m_ec^2  \left( \begin{array}{c} \Psi^L \\-\Psi^S \end{array} \right) + V  \left( \begin{array}{c}\Psi^L \\\Psi^S \end{array} \right)$

The index.rst file with the sole math formula is attached.

I have most recent Ubuntu 12.10 (x86_64) with default packages python-sphinx 1.1.2, python-matplotlib 1.1.1.

Any help, please ? I was trying to cut this formula down; the smallest LaTeX part not rendered is "\begin{array}{c}\Psi^L \\ \Psi^S \end{array}".

Yours, 

Miro

[Matplotlib-users] ANN: matplotlib 1.2.1 release

[Michael D. <md...@st...>]

I'm pleased to announce the release of matplotlib 1.2.1.  This is a bug 
release and improves stability and quality over the 1.2.0 release from 
four months ago.  All users on 1.2.0 are encouraged to upgrade.

Since github no longer provides download hosting, our tarballs and 
binaries are back on SourceForge, and we have a master index of 
downloads here:

http://matplotlib.org/downloads <http://matplotlib.org/downloads.html>

Highlights include:

- Usage of deprecated APIs in matplotlib are now displayed by default on 
all Python versions
- Agg backend: Cleaner rendering of rectilinear lines when snapping to 
pixel boundaries, and fixes rendering bugs when using clip paths
- Python 3: Fixes a number of missed Python 3 compatibility problems
- Histograms and stacked histograms have a number of important bugfixes
- Compatibility with more 3rd-party TrueType fonts
- SVG backend: Image support in SVG output is consistent with other backends
- Qt backend: Fixes leaking of window objects in Qt backend
- hexbin with a log scale now works correctly
- autoscaling works better on 3D plots
- ...and numerous others.

Enjoy!  As always, there are number of good ways to get help with 
matplotlib listed on the homepage at http://matplotlib.org/ and I thank 
everyone for their continued support of this project.

Mike Droettboom

Re: [Matplotlib-users] Trouble with legend and axis scaling

[Sterling S. <sm...@fu...>]

Frix,

I get the same error for your first example with v1.1.1 [although I had to comment out the med_r = np.median(x_r) to get it to run].  You should probably file a bug at [1].

I get the same result for your yaxis.  You need to change the formatter to 

ax.yaxis.set_major_formatter(plt.ScalarFormatter(useOffset=False))

-Sterling

[1] https://github.com/matplotlib/matplotlib/issues

On Mar 27, 2013, at 7:09AM, Hackstein wrote:

> Sterling,
> 
> I'm using matplotlib version 1.2.0 with agg backend.
> 
> Here are two code examples, one for each problem. The first one doesn't save the figure due to the legend problem, seterr causes the script to stop with an error at that position.
> The second example shows the scientific labels on the y-axis, although it should be disabled in the code. I can't get the y-axis to display plain labels. 
> 
> First example:
> [code]
> import numpy as np
> np.seterr(all='raise')
> import matplotlib.pyplot as plt
> 
> x_i = [11.7574075935, 11.665207135799999, 11.6762413105, 11.6580992311, 11.656368388500001]
> x_r = []
> dates = [2.83611000e-01,   2.69330463e+02,   2.70280648e+02,   2.71359248e+02,   2.72320822e+02]
> 
> diff = 0.16
> ra = [0., 110.5349726]
> dec = [0., -16.1061281]
> med_i = np.median(x_i)
> med_r = np.median(x_r)
> 
> plt.figure("i_only", figsize=(14.40, 9.00), dpi=100)
> if x_r == []:
>   plt.plot(dates, np.asarray(x_i), 'r-', label = 'i_s')
>   plt.title('i_mag', fontsize='16')
> else:
>   plt.plot(dates, np.asarray(x_r), 'g-', label = 'r_s')
>   plt.plot(dates, np.asarray(x_i), 'r-', label = 'i_s')
>   plt.title('i_mag', fontsize='16')
> plt.rcParams['xtick.major.pad']=10
> plt.rcParams['ytick.major.pad']=10
> ax = plt.gca()
> ax.title.set_y(1.1)
> formy = plt.ScalarFormatter()
> formy.set_powerlimits((-5, 5))
> formy.set_scientific(False)
> ax.yaxis.set_major_formatter(formy)
> ax.set_ylim(ax.get_ylim()[::-1])
> for tick in ax.xaxis.get_major_ticks():
>   tick.label.set_fontsize(16)
> for tick in ax.yaxis.get_major_ticks():
>   tick.label.set_fontsize(16)
> plt.xlabel('Days', fontsize='20', labelpad=20)
> plt.ylabel('normalized magnitude / mag', fontsize='20', labelpad=20)
> 
> if x_r == []:
>   plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
>              numpoints=1, ncol=2, borderaxespad=0.)
> else:
>   plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
>              numpoints=1, ncol=2, borderaxespad=0.)
> leg = plt.gca().get_legend()
> ltext = leg.get_texts()
> plt.setp(ltext, fontsize='16')
> plt.savefig('lc0.png', facecolor='white', bbox_inches='tight')
> plt.close("i_only")
> [/code]
> 
> Second example:
> [code]
> import numpy as np
> import matplotlib.pyplot as plt
> 
> y_i = [11.1044563514, 11.1228276748, 11.1361234115, 11.1298162168, 11.125134152199999]
> y_r = [11.148667168999999, 11.10194503, 11.112352465300001, 11.111687871799999, 11.1214449011]
> dates_i = [2.83611000e-01,   2.69330463e+02, 2.70280648e+02,   2.72320822e+02, 2.73250579e+02]
> dates_r = [311.28215,   324.25844,   325.25194,   330.20983,   338.21356]
> 
> diff = 0.16
> ra = [112.5379659, 110.5349726]
> dec = [ -15.9841039, -16.1061281]
> med_i = np.median(y_i)
> med_r = np.median(y_r)
> 
> plt.figure("i_only", figsize=(14.40, 9.00), dpi=100)
> if y_r == []:
>    plt.plot(dates_i, np.asarray(y_i), 'r-', label = 'i_s')
>    plt.title('i_mag', fontsize='16')
> else:
>    plt.plot(dates_r, np.asarray(y_r), 'g-', label = 'r_s')
>    plt.plot(dates_i, np.asarray(y_i), 'r-', label = 'i_s')
>    plt.title('i_mag', fontsize='16')
> plt.rcParams['xtick.major.pad']=10
> plt.rcParams['ytick.major.pad']=10
> ax = plt.gca()
> ax.title.set_y(1.1)
> formy = plt.ScalarFormatter()
> formy.set_powerlimits((-5, 5))
> formy.set_scientific(False)
> ax.yaxis.set_major_formatter(formy)
> ax.set_ylim(ax.get_ylim()[::-1])
> for tick in ax.xaxis.get_major_ticks():
>    tick.label.set_fontsize(16)
> for tick in ax.yaxis.get_major_ticks():
>    tick.label.set_fontsize(16)
> plt.xlabel('Days', fontsize='20', labelpad=20)
> plt.ylabel('normalized magnitude / mag', fontsize='20', labelpad=20)
> 
> if y_r == []:
>    plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
>               numpoints=1, ncol=2, borderaxespad=0.)
> else:
>    plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
>               numpoints=1, ncol=2, borderaxespad=0.)
> leg = plt.gca().get_legend()
> ltext = leg.get_texts()
> plt.setp(ltext, fontsize='16')
> plt.savefig('lc0.png', facecolor='white', bbox_inches='tight')
> plt.close("i_only") 
> [/code]
> 
> Best regards,
> 
> frix
> 
> 
> Am 26.03.2013 um 20:36 schrieb Sterling Smith <sm...@fu...>:
> 
>> Frix,
>> 
>> It may be useful to post the version and backend you are using to the list.
>> 
>> import matplotlib
>> print matplotlib.__version__
>> print matplotlib.get_backend()
>> 
>> Also, if you can format the code as a simple self-contained example, that would help others confirm what you are seeing.
>> 
>> -Sterling
>> 
>> On Mar 26, 2013, at 12:01PM, Hackstein wrote:
>> 
>>> Hello everyone,
>>> 
>>> I have two issues with my current projects:
>>> 
>>> 1)  I automatically generate plots of several data sets in a for-loop, all of which have the same shape of x and y values, but some of which have two of those data (i.e. graphs) sets per figure, others have only one.
>>> I create the legend by
>>> 
>>> plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand', numpoints=1, borderaxespad=0.)
>>> 
>>> which works perfectly if I plot two data sets (and therefore two labels) in a figure, but sometimes (not always) causes an error, if only one data set is plotted in a figure.
>>> The legend is this
>>> 
>>> print ax.get_legend_handles_labels()
>>> ([<matplotlib.lines.Line2D object at 0x24b9550>], ['i_s'])
>>> 
>>> and the error is
>>> 
>>> File "/usr/lib64/python2.6/site-packages/matplotlib/offsetbox.py", line 76, in _get_packed_offsets
>>>  sep = (total - sum(w_list)) / (len(w_list) - 1.)
>>> FloatingPointError: divide by zero encountered in double_scalars
>>> 
>>> which I broke down to a problem with the" mode='expand'" parameter. It seems it cannot expand when the number of labels is 1. Strangely, however, that seems not always to be the case, since some of the plots with only one data set and one legend entry work without problems, but some raise an error.
>>> 
>>> 2) Another problem occurs with the y-axis tick labels. Even if the y-values are quite ordinary (in the order of 10) the labels get scientific notation when the y-range is small (order 0.1). I don't know why that is and it only occurs then. When the y-range is larger (order of 1), the ticks get plain numbers. I tried to work around that with the following code, which did not
>>> work:
>>> 
>>> plt.figure("i_only", figsize=(14.40, 9.00), dpi=100) plt.plot(np.asarray(mod_mjd_list_i), np.asarray(x_i), 'r-', label = 'i_s') ax = plt.gca() formy = plt.ScalarFormatter() formy.set_powerlimits((-5, 5))
>>> formy.set_scientific(False)
>>> ax.yaxis.set_major_formatter(formy)
>>> 
>>> Any ideas what I can do?
>>> 
>>> Thanks,
>>> frix
>>> 
>>> 
>>> ------------------------------------------------------------------------------
>>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>>> Rise to greatness in Intel's independent game demo contest.
>>> Compete for recognition, cash, and the chance to get your game 
>>> on Steam. $5K grand prize plus 10 genre and skill prizes. 
>>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d_______________________________________________
>>> Matplotlib-users mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>> 

Re: [Matplotlib-users] Plotting from datafile

[Sayan C. <say...@gm...>]

Hi Steven,

I am a newbie to Python and hence Matplotlib. I cannot get your point
properly. Could you please redirect me to a page where the usage is
demonstrated?

As I can see, you're a doctoral student in Physics, it might be worthwhile
to tell you that I'm trying to code a  Zeldovich Approximation for a simple
sinusoidal potential and want to make it evolve with varying scale factor
and make an animation of it.

Cheers,
Sayan


On 27 March 2013 19:58, Steven Boada <bo...@ph...> wrote:

> Another, slightly more flexible, option is the genfromtxt function, also
> in numpy. Normally you should try genfromtxt after loadtxt doesn't work.
> Or, that is my normal method.
>
> Steven
>
>
> On Wed Mar 27 07:16:45 2013, Sayan Chatterjee wrote:
>
>> Thank you very much for your prompt reply.
>>
>> Florian,  your reply seems to be the answer to my question. I'll try
>> it out. If can't figure out,I'll get back to you.
>>
>>
>> On 27 March 2013 15:37, Florian M. Wagner <wag...@st...
>> <mailto:wag...@st....**ch <wag...@st...>>> wrote:
>>
>>     Hey Sayan,
>>
>>     for reading in simple ASCII-Files containing your two arrays you
>>     should have a look at the numpy.loadtxt function.
>>
>>     Scatter plots in matplotlib are then easily created as shown here
>>     http://matplotlib.org/**examples/pylab_examples/**scatter_demo.html<http://matplotlib.org/examples/pylab_examples/scatter_demo.html>
>>
>>     For your purpose you can do something like:
>>
>>         import os
>>         import numpy as np
>>         import matplotlib.pyplot as plt
>>
>>         for file in os.path.listdir():
>>             x, y = np.loadtxt(file, unpack=True)
>>             plt.scatter(x,y)
>>             plt.savefig(file + '.png')
>>
>>     Cheers,
>>
>>     Florian
>>
>>
>>     Am 27.03.2013 09:32, schrieb Sayan Chatterjee:
>>
>>>     Dear All,
>>>
>>>     I'm new to Matplotlib. It might be a silly question, how does one
>>>     plot data(not functions) in Matplotlib.
>>>
>>>     How:
>>>     1)Two arrays (X and Y) can be plotted in a scatter diagram?
>>>
>>>     2) or a number of data files can used to produce different plots
>>>     having different(sequential) name?
>>>
>>>     Thanks in anticipation.
>>>     Regards,
>>>     Sayan
>>>
>>>     --
>>>
>>>
>>>     ------------------------------**------------------------------**
>>> --------------
>>>     *Sayan  Chatterjee*
>>>
>>>     Dept. of Physics and Meteorology
>>>     IIT Kharagpur
>>>     Lal Bahadur Shastry Hall of Residence
>>>     Room AB 205
>>>     Mob: +91 9874513565
>>>     blog: www.blissprofound.blogspot.com
>>>     <http://www.blissprofound.**blogspot.com<http://www.blissprofound.blogspot.com>
>>> >
>>>
>>>     Volunteer , Padakshep
>>>     www.padakshep.org <http://www.padakshep.org>
>>>
>>>
>>>
>>>     ------------------------------**------------------------------**
>>> ------------------
>>>     Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>>>     Rise to greatness in Intel's independent game demo contest.
>>>     Compete for recognition, cash, and the chance to get your game
>>>     on Steam. $5K grand prize plus 10 genre and skill prizes.
>>>     Submit your demo by 6/6/13.http://p.sf.net/sfu/**intel_levelupd2d<http://p.sf.net/sfu/intel_levelupd2d>
>>>
>>>
>>>     ______________________________**_________________
>>>     Matplotlib-users mailing list
>>>     Matplotlib-users@lists.**sourceforge.net<Mat...@li...> <mailto:
>>> Matplotlib-users@**lists.sourceforge.net<Mat...@li...>
>>> >
>>>     https://lists.sourceforge.net/**lists/listinfo/matplotlib-**users<https://lists.sourceforge.net/lists/listinfo/matplotlib-users>
>>>
>>
>>
>>     ------------------------------**------------------------------**
>> ------------------
>>     Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>>     Rise to greatness in Intel's independent game demo contest.
>>     Compete for recognition, cash, and the chance to get your game
>>     on Steam. $5K grand prize plus 10 genre and skill prizes.
>>     Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_**levelupd2d<http://p.sf.net/sfu/intel_levelupd2d>
>>     ______________________________**_________________
>>     Matplotlib-users mailing list
>>     Matplotlib-users@lists.**sourceforge.net<Mat...@li...>
>>     <mailto:Matplotlib-users@**lists.sourceforge.net<Mat...@li...>
>> >
>>     https://lists.sourceforge.net/**lists/listinfo/matplotlib-**users<https://lists.sourceforge.net/lists/listinfo/matplotlib-users>
>>
>>
>>
>>
>> --
>>
>>
>> ------------------------------**------------------------------**
>> --------------
>> *Sayan  Chatterjee*
>>
>> Dept. of Physics and Meteorology
>> IIT Kharagpur
>> Lal Bahadur Shastry Hall of Residence
>> Room AB 205
>> Mob: +91 9874513565
>> blog: www.blissprofound.blogspot.com
>> <http://www.blissprofound.**blogspot.com<http://www.blissprofound.blogspot.com>
>> >
>>
>> Volunteer , Padakshep
>> www.padakshep.org <http://www.padakshep.org>
>>
>>
>>
>> ------------------------------**------------------------------**
>> ------------------
>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>> Rise to greatness in Intel's independent game demo contest.
>> Compete for recognition, cash, and the chance to get your game
>> on Steam. $5K grand prize plus 10 genre and skill prizes.
>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_**levelupd2d<http://p.sf.net/sfu/intel_levelupd2d>
>>
>>
>> ______________________________**_________________
>> Matplotlib-users mailing list
>> Matplotlib-users@lists.**sourceforge.net<Mat...@li...>
>> https://lists.sourceforge.net/**lists/listinfo/matplotlib-**users<https://lists.sourceforge.net/lists/listinfo/matplotlib-users>
>>
>
> --
>
> Steven Boada
>
> Doctoral Student
> Dept of Physics and Astronomy
> Texas A&M University
> bo...@ph...
>



-- 


--------------------------------------------------------------------------
*Sayan  Chatterjee*
Dept. of Physics and Meteorology
IIT Kharagpur
Lal Bahadur Shastry Hall of Residence
Room AB 205
Mob: +91 9874513565
blog: www.blissprofound.blogspot.com

Volunteer , Padakshep
www.padakshep.org

Re: [Matplotlib-users] Plotting from datafile

[Steven B. <bo...@ph...>]

Another, slightly more flexible, option is the genfromtxt function, 
also in numpy. Normally you should try genfromtxt after loadtxt doesn't 
work. Or, that is my normal method.

Steven

On Wed Mar 27 07:16:45 2013, Sayan Chatterjee wrote:
> Thank you very much for your prompt reply.
>
> Florian,  your reply seems to be the answer to my question. I'll try
> it out. If can't figure out,I'll get back to you.
>
>
> On 27 March 2013 15:37, Florian M. Wagner <wag...@st...
> <mailto:wag...@st...>> wrote:
>
>     Hey Sayan,
>
>     for reading in simple ASCII-Files containing your two arrays you
>     should have a look at the numpy.loadtxt function.
>
>     Scatter plots in matplotlib are then easily created as shown here
>     http://matplotlib.org/examples/pylab_examples/scatter_demo.html
>
>     For your purpose you can do something like:
>
>         import os
>         import numpy as np
>         import matplotlib.pyplot as plt
>
>         for file in os.path.listdir():
>             x, y = np.loadtxt(file, unpack=True)
>             plt.scatter(x,y)
>             plt.savefig(file + '.png')
>
>     Cheers,
>
>     Florian
>
>
>     Am 27.03.2013 09:32, schrieb Sayan Chatterjee:
>>     Dear All,
>>
>>     I'm new to Matplotlib. It might be a silly question, how does one
>>     plot data(not functions) in Matplotlib.
>>
>>     How:
>>     1)Two arrays (X and Y) can be plotted in a scatter diagram?
>>
>>     2) or a number of data files can used to produce different plots
>>     having different(sequential) name?
>>
>>     Thanks in anticipation.
>>     Regards,
>>     Sayan
>>
>>     --
>>
>>
>>     --------------------------------------------------------------------------
>>     *Sayan  Chatterjee*
>>     Dept. of Physics and Meteorology
>>     IIT Kharagpur
>>     Lal Bahadur Shastry Hall of Residence
>>     Room AB 205
>>     Mob: +91 9874513565
>>     blog: www.blissprofound.blogspot.com
>>     <http://www.blissprofound.blogspot.com>
>>
>>     Volunteer , Padakshep
>>     www.padakshep.org <http://www.padakshep.org>
>>
>>
>>     ------------------------------------------------------------------------------
>>     Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>>     Rise to greatness in Intel's independent game demo contest.
>>     Compete for recognition, cash, and the chance to get your game
>>     on Steam. $5K grand prize plus 10 genre and skill prizes.
>>     Submit your demo by 6/6/13.http://p.sf.net/sfu/intel_levelupd2d
>>
>>
>>     _______________________________________________
>>     Matplotlib-users mailing list
>>     Mat...@li...  <mailto:Mat...@li...>
>>     https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>
>     ------------------------------------------------------------------------------
>     Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>     Rise to greatness in Intel's independent game demo contest.
>     Compete for recognition, cash, and the chance to get your game
>     on Steam. $5K grand prize plus 10 genre and skill prizes.
>     Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>     _______________________________________________
>     Matplotlib-users mailing list
>     Mat...@li...
>     <mailto:Mat...@li...>
>     https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>
>
>
> --
>
>
> --------------------------------------------------------------------------
> *Sayan  Chatterjee*
> Dept. of Physics and Meteorology
> IIT Kharagpur
> Lal Bahadur Shastry Hall of Residence
> Room AB 205
> Mob: +91 9874513565
> blog: www.blissprofound.blogspot.com
> <http://www.blissprofound.blogspot.com>
>
> Volunteer , Padakshep
> www.padakshep.org <http://www.padakshep.org>
>
>
> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game
> on Steam. $5K grand prize plus 10 genre and skill prizes.
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>
>
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

--

Steven Boada

Doctoral Student
Dept of Physics and Astronomy
Texas A&M University
bo...@ph...

Re: [Matplotlib-users] Trouble with legend and axis scaling

[Hackstein <new...@gm...>]

Sterling,

I'm using matplotlib version 1.2.0 with agg backend.

Here are two code examples, one for each problem. The first one doesn't save the figure due to the legend problem, seterr causes the script to stop with an error at that position.
The second example shows the scientific labels on the y-axis, although it should be disabled in the code. I can't get the y-axis to display plain labels. 

First example:
[code]
import numpy as np
np.seterr(all='raise')
import matplotlib.pyplot as plt

x_i = [11.7574075935, 11.665207135799999, 11.6762413105, 11.6580992311, 11.656368388500001]
x_r = []
dates = [2.83611000e-01,   2.69330463e+02,   2.70280648e+02,   2.71359248e+02,   2.72320822e+02]

diff = 0.16
ra = [0., 110.5349726]
dec = [0., -16.1061281]
med_i = np.median(x_i)
med_r = np.median(x_r)

plt.figure("i_only", figsize=(14.40, 9.00), dpi=100)
if x_r == []:
   plt.plot(dates, np.asarray(x_i), 'r-', label = 'i_s')
   plt.title('i_mag', fontsize='16')
else:
   plt.plot(dates, np.asarray(x_r), 'g-', label = 'r_s')
   plt.plot(dates, np.asarray(x_i), 'r-', label = 'i_s')
   plt.title('i_mag', fontsize='16')
plt.rcParams['xtick.major.pad']=10
plt.rcParams['ytick.major.pad']=10
ax = plt.gca()
ax.title.set_y(1.1)
formy = plt.ScalarFormatter()
formy.set_powerlimits((-5, 5))
formy.set_scientific(False)
ax.yaxis.set_major_formatter(formy)
ax.set_ylim(ax.get_ylim()[::-1])
for tick in ax.xaxis.get_major_ticks():
   tick.label.set_fontsize(16)
for tick in ax.yaxis.get_major_ticks():
   tick.label.set_fontsize(16)
plt.xlabel('Days', fontsize='20', labelpad=20)
plt.ylabel('normalized magnitude / mag', fontsize='20', labelpad=20)

if x_r == []:
   plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
              numpoints=1, ncol=2, borderaxespad=0.)
else:
   plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
              numpoints=1, ncol=2, borderaxespad=0.)
leg = plt.gca().get_legend()
ltext = leg.get_texts()
plt.setp(ltext, fontsize='16')
plt.savefig('lc0.png', facecolor='white', bbox_inches='tight')
plt.close("i_only")
[/code]

Second example:
[code]
import numpy as np
import matplotlib.pyplot as plt

y_i = [11.1044563514, 11.1228276748, 11.1361234115, 11.1298162168, 11.125134152199999]
y_r = [11.148667168999999, 11.10194503, 11.112352465300001, 11.111687871799999, 11.1214449011]
dates_i = [2.83611000e-01,   2.69330463e+02, 2.70280648e+02,   2.72320822e+02, 2.73250579e+02]
dates_r = [311.28215,   324.25844,   325.25194,   330.20983,   338.21356]
        
diff = 0.16
ra = [112.5379659, 110.5349726]
dec = [ -15.9841039, -16.1061281]
med_i = np.median(y_i)
med_r = np.median(y_r)

plt.figure("i_only", figsize=(14.40, 9.00), dpi=100)
if y_r == []:
    plt.plot(dates_i, np.asarray(y_i), 'r-', label = 'i_s')
    plt.title('i_mag', fontsize='16')
else:
    plt.plot(dates_r, np.asarray(y_r), 'g-', label = 'r_s')
    plt.plot(dates_i, np.asarray(y_i), 'r-', label = 'i_s')
    plt.title('i_mag', fontsize='16')
plt.rcParams['xtick.major.pad']=10
plt.rcParams['ytick.major.pad']=10
ax = plt.gca()
ax.title.set_y(1.1)
formy = plt.ScalarFormatter()
formy.set_powerlimits((-5, 5))
formy.set_scientific(False)
ax.yaxis.set_major_formatter(formy)
ax.set_ylim(ax.get_ylim()[::-1])
for tick in ax.xaxis.get_major_ticks():
    tick.label.set_fontsize(16)
for tick in ax.yaxis.get_major_ticks():
    tick.label.set_fontsize(16)
plt.xlabel('Days', fontsize='20', labelpad=20)
plt.ylabel('normalized magnitude / mag', fontsize='20', labelpad=20)

if y_r == []:
    plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
               numpoints=1, ncol=2, borderaxespad=0.)
else:
    plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
               numpoints=1, ncol=2, borderaxespad=0.)
leg = plt.gca().get_legend()
ltext = leg.get_texts()
plt.setp(ltext, fontsize='16')
plt.savefig('lc0.png', facecolor='white', bbox_inches='tight')
plt.close("i_only") 
[/code]

Best regards,

frix


Am 26.03.2013 um 20:36 schrieb Sterling Smith <sm...@fu...>:

> Frix,
> 
> It may be useful to post the version and backend you are using to the list.
> 
> import matplotlib
> print matplotlib.__version__
> print matplotlib.get_backend()
> 
> Also, if you can format the code as a simple self-contained example, that would help others confirm what you are seeing.
> 
> -Sterling
> 
> On Mar 26, 2013, at 12:01PM, Hackstein wrote:
> 
>> Hello everyone,
>> 
>> I have two issues with my current projects:
>> 
>> 1)  I automatically generate plots of several data sets in a for-loop, all of which have the same shape of x and y values, but some of which have two of those data (i.e. graphs) sets per figure, others have only one.
>> I create the legend by
>> 
>> plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand', numpoints=1, borderaxespad=0.)
>> 
>> which works perfectly if I plot two data sets (and therefore two labels) in a figure, but sometimes (not always) causes an error, if only one data set is plotted in a figure.
>> The legend is this
>> 
>> print ax.get_legend_handles_labels()
>> ([<matplotlib.lines.Line2D object at 0x24b9550>], ['i_s'])
>> 
>> and the error is
>> 
>> File "/usr/lib64/python2.6/site-packages/matplotlib/offsetbox.py", line 76, in _get_packed_offsets
>>   sep = (total - sum(w_list)) / (len(w_list) - 1.)
>> FloatingPointError: divide by zero encountered in double_scalars
>> 
>> which I broke down to a problem with the" mode='expand'" parameter. It seems it cannot expand when the number of labels is 1. Strangely, however, that seems not always to be the case, since some of the plots with only one data set and one legend entry work without problems, but some raise an error.
>> 
>> 2) Another problem occurs with the y-axis tick labels. Even if the y-values are quite ordinary (in the order of 10) the labels get scientific notation when the y-range is small (order 0.1). I don't know why that is and it only occurs then. When the y-range is larger (order of 1), the ticks get plain numbers. I tried to work around that with the following code, which did not
>> work:
>> 
>> plt.figure("i_only", figsize=(14.40, 9.00), dpi=100) plt.plot(np.asarray(mod_mjd_list_i), np.asarray(x_i), 'r-', label = 'i_s') ax = plt.gca() formy = plt.ScalarFormatter() formy.set_powerlimits((-5, 5))
>> formy.set_scientific(False)
>> ax.yaxis.set_major_formatter(formy)
>> 
>> Any ideas what I can do?
>> 
>> Thanks,
>> frix
>> 
>> 
>> ------------------------------------------------------------------------------
>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>> Rise to greatness in Intel's independent game demo contest.
>> Compete for recognition, cash, and the chance to get your game 
>> on Steam. $5K grand prize plus 10 genre and skill prizes. 
>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d_______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> 

Re: [Matplotlib-users] set_scale and set_xscale

[Benjamin R. <ben...@ou...>]

On Wed, Mar 27, 2013 at 1:03 AM, Gökhan Sever <gok...@gm...> wrote:

> Hello,
>
> Aren't these two log scaling calls supposed to be performing the same
> action?
>
> Here is a simple script tested in ipython --pylab
>
> fig = plt.figure(figsize=(5, 5))
> ax1 = fig.add_subplot(1,1,1)
> ax1.plot(np.random.randn(100))
>
> ax1.xaxis.set_scale('log')
> ax1.set_xscale('log')
>
>
Intuitively, I guess they should be identical, but they don't seem to be.
It seems like for "ax1.xaxis.set_scale('log')", everything is set
correctly, except the projection.

Ben Root

[Matplotlib-users] ANN: matplotlib 1.2.1 release

[Michael D. <md...@st...>]

I'm pleased to announce the release of matplotlib 1.2.1.  This is a bug 
release and improves stability and quality over the 1.2.0 release from 
four months ago.  All users on 1.2.0 are encouraged to upgrade.

Since github no longer provides download hosting, our tarballs and 
binaries are back on SourceForge, and we have a master index of 
downloads here:

http://matplotlib.org/downloads <http://matplotlib.org/downloads.html>

Highlights include:

- Usage of deprecated APIs in matplotlib are now displayed by default on 
all Python versions
- Agg backend: Cleaner rendering of rectilinear lines when snapping to 
pixel boundaries, and fixes rendering bugs when using clip paths
- Python 3: Fixes a number of missed Python 3 compatibility problems
- Histograms and stacked histograms have a number of important bugfixes
- Compatibility with more 3rd-party TrueType fonts
- SVG backend: Image support in SVG output is consistent with other backends
- Qt backend: Fixes leaking of window objects in Qt backend
- hexbin with a log scale now works correctly
- autoscaling works better on 3D plots
- ...and numerous others.

Enjoy!  As always, there are number of good ways to get help with 
matplotlib listed on the homepage at http://matplotlib.org/ and I thank 
everyone for their continued support of this project.

Mike Droettboom

Re: [Matplotlib-users] Plotting from datafile

[Alexander E. <ale...@ov...>]

On Wed, 27 Mar 2013 14:02:58 +0530
Sayan Chatterjee <say...@gm...> wrote:

> I'm new to Matplotlib. It might be a silly question, how does one plot
> data(not functions) in Matplotlib.

Besides the solution given in the first reply, you may also check
https://github.com/dmcdougall/mpl_binutils

Regards

Alex

Re: [Matplotlib-users] Plotting from datafile

[Sayan C. <say...@gm...>]

Thank you very much for your prompt reply.

Florian,  your reply seems to be the answer to my question. I'll try it
out. If can't figure out,I'll get back to you.


On 27 March 2013 15:37, Florian M. Wagner <wag...@st...> wrote:

>  Hey Sayan,
>
> for reading in simple ASCII-Files containing your two arrays you should
> have a look at the numpy.loadtxt function.
>
> Scatter plots in matplotlib are then easily created as shown here
> http://matplotlib.org/examples/pylab_examples/scatter_demo.html
>
> For your purpose you can do something like:
>
> import os
> import numpy as np
> import matplotlib.pyplot as plt
>
> for file in os.path.listdir():
>     x, y = np.loadtxt(file, unpack=True)
>     plt.scatter(x,y)
>     plt.savefig(file + '.png')
>
>  Cheers,
>
> Florian
>
>
> Am 27.03.2013 09:32, schrieb Sayan Chatterjee:
>
> Dear All,
>
> I'm new to Matplotlib. It might be a silly question, how does one plot
> data(not functions) in Matplotlib.
>
>  How:
>  1)Two arrays (X and Y) can be plotted in a scatter diagram?
>
>  2) or a number of data files can used to produce different plots having
> different(sequential) name?
>
>  Thanks in anticipation.
> Regards,
> Sayan
>
>  --
>
>
>  --------------------------------------------------------------------------
> *Sayan  Chatterjee*
> Dept. of Physics and Meteorology
>  IIT Kharagpur
> Lal Bahadur Shastry Hall of Residence
> Room AB 205
> Mob: +91 9874513565
> blog: www.blissprofound.blogspot.com
>
> Volunteer , Padakshep
> www.padakshep.org
>
>
> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game
> on Steam. $5K grand prize plus 10 genre and skill prizes.
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>
>
>
> _______________________________________________
> Matplotlib-users mailing lis...@li...://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>
>
>
> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game
> on Steam. $5K grand prize plus 10 genre and skill prizes.
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>


-- 


--------------------------------------------------------------------------
*Sayan  Chatterjee*
Dept. of Physics and Meteorology
IIT Kharagpur
Lal Bahadur Shastry Hall of Residence
Room AB 205
Mob: +91 9874513565
blog: www.blissprofound.blogspot.com

Volunteer , Padakshep
www.padakshep.org

Re: [Matplotlib-users] Plotting from datafile

[Florian M. W. <wag...@st...>]

Hey Sayan,

for reading in simple ASCII-Files containing your two arrays you should 
have a look at the numpy.loadtxt function.

Scatter plots in matplotlib are then easily created as shown here 
http://matplotlib.org/examples/pylab_examples/scatter_demo.html

For your purpose you can do something like:

    import os
    import numpy as np
    import matplotlib.pyplot as plt

    for file in os.path.listdir():
         x, y = np.loadtxt(file, unpack=True)
         plt.scatter(x,y)
         plt.savefig(file + '.png')

Cheers,

Florian


Am 27.03.2013 09:32, schrieb Sayan Chatterjee:
> Dear All,
>
> I'm new to Matplotlib. It might be a silly question, how does one plot 
> data(not functions) in Matplotlib.
>
> How:
> 1)Two arrays (X and Y) can be plotted in a scatter diagram?
>
> 2) or a number of data files can used to produce different plots 
> having different(sequential) name?
>
> Thanks in anticipation.
> Regards,
> Sayan
>
> -- 
>
>
> --------------------------------------------------------------------------
> *Sayan  Chatterjee*
> Dept. of Physics and Meteorology
> IIT Kharagpur
> Lal Bahadur Shastry Hall of Residence
> Room AB 205
> Mob: +91 9874513565
> blog: www.blissprofound.blogspot.com 
> <http://www.blissprofound.blogspot.com>
>
> Volunteer , Padakshep
> www.padakshep.org <http://www.padakshep.org>
>
>
> ------------------------------------------------------------------------------
> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
> Rise to greatness in Intel's independent game demo contest.
> Compete for recognition, cash, and the chance to get your game
> on Steam. $5K grand prize plus 10 genre and skill prizes.
> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>
>
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

[Matplotlib-users] Plotting from datafile

[Sayan C. <say...@gm...>]

Dear All,

I'm new to Matplotlib. It might be a silly question, how does one plot
data(not functions) in Matplotlib.

How:
1)Two arrays (X and Y) can be plotted in a scatter diagram?

2) or a number of data files can used to produce different plots having
different(sequential) name?

Thanks in anticipation.
Regards,
Sayan

-- 


--------------------------------------------------------------------------
*Sayan  Chatterjee*
Dept. of Physics and Meteorology
IIT Kharagpur
Lal Bahadur Shastry Hall of Residence
Room AB 205
Mob: +91 9874513565
blog: www.blissprofound.blogspot.com

Volunteer , Padakshep
www.padakshep.org

[Matplotlib-users] set_scale and set_xscale

[Gökhan S. <gok...@gm...>]

Hello,

Aren't these two log scaling calls supposed to be performing the same
action?

Here is a simple script tested in ipython --pylab

fig = plt.figure(figsize=(5, 5))
ax1 = fig.add_subplot(1,1,1)
ax1.plot(np.random.randn(100))

ax1.xaxis.set_scale('log')
ax1.set_xscale('log')

Thanks.

-- 
Gökhan

Re: [Matplotlib-users] Trouble with legend and axis scaling

[Sterling S. <sm...@fu...>]

Frix,

It may be useful to post the version and backend you are using to the list.

import matplotlib
print matplotlib.__version__
print matplotlib.get_backend()

Also, if you can format the code as a simple self-contained example, that would help others confirm what you are seeing.

-Sterling

On Mar 26, 2013, at 12:01PM, Hackstein wrote:

> Hello everyone,
>  
> I have two issues with my current projects:
>  
> 1)  I automatically generate plots of several data sets in a for-loop, all of which have the same shape of x and y values, but some of which have two of those data (i.e. graphs) sets per figure, others have only one.
> I create the legend by
>  
> plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand', numpoints=1, borderaxespad=0.)
>  
> which works perfectly if I plot two data sets (and therefore two labels) in a figure, but sometimes (not always) causes an error, if only one data set is plotted in a figure.
> The legend is this
>  
> print ax.get_legend_handles_labels()
> ([<matplotlib.lines.Line2D object at 0x24b9550>], ['i_s'])
>  
> and the error is
>  
> File "/usr/lib64/python2.6/site-packages/matplotlib/offsetbox.py", line 76, in _get_packed_offsets
>     sep = (total - sum(w_list)) / (len(w_list) - 1.)
> FloatingPointError: divide by zero encountered in double_scalars
>  
> which I broke down to a problem with the" mode='expand'" parameter. It seems it cannot expand when the number of labels is 1. Strangely, however, that seems not always to be the case, since some of the plots with only one data set and one legend entry work without problems, but some raise an error.
>  
> 2) Another problem occurs with the y-axis tick labels. Even if the y-values are quite ordinary (in the order of 10) the labels get scientific notation when the y-range is small (order 0.1). I don't know why that is and it only occurs then. When the y-range is larger (order of 1), the ticks get plain numbers. I tried to work around that with the following code, which did not
> work:
>  
> plt.figure("i_only", figsize=(14.40, 9.00), dpi=100) plt.plot(np.asarray(mod_mjd_list_i), np.asarray(x_i), 'r-', label = 'i_s') ax = plt.gca() formy = plt.ScalarFormatter() formy.set_powerlimits((-5, 5))
> formy.set_scientific(False)
> ax.yaxis.set_major_formatter(formy)
>  
> Any ideas what I can do?
>  
> Thanks,
> frix
>  
>  
> ------------------------------------------------------------------------------
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[Matplotlib-users] Trouble with legend and axis scaling

[Hackstein <new...@gm...>]

Hello everyone,

 

I have two issues with my current projects:

 

1)  I automatically generate plots of several data sets in a for-loop, all
of which have the same shape of x and y values, but some of which have two
of those data (i.e. graphs) sets per figure, others have only one.

I create the legend by 

 

plt.legend(bbox_to_anchor=(0., 1.02, 1., 0.102), loc=3, mode='expand',
numpoints=1, borderaxespad=0.)

 

which works perfectly if I plot two data sets (and therefore two labels) in
a figure, but sometimes (not always) causes an error, if only one data set
is plotted in a figure.

The legend is this

 

print ax.get_legend_handles_labels()

([<matplotlib.lines.Line2D object at 0x24b9550>], ['i_s'])

 

and the error is 

 

File "/usr/lib64/python2.6/site-packages/matplotlib/offsetbox.py", line 76,
in _get_packed_offsets

    sep = (total - sum(w_list)) / (len(w_list) - 1.)

FloatingPointError: divide by zero encountered in double_scalars

 

which I broke down to a problem with the" mode='expand'" parameter. It seems
it cannot expand when the number of labels is 1. Strangely, however, that
seems not always to be the case, since some of the plots with only one data
set and one legend entry work without problems, but some raise an error. 

 

2) Another problem occurs with the y-axis tick labels. Even if the y-values
are quite ordinary (in the order of 10) the labels get scientific notation
when the y-range is small (order 0.1). I don't know why that is and it only
occurs then. When the y-range is larger (order of 1), the ticks get plain
numbers. I tried to work around that with the following code, which did not

work:

 

plt.figure("i_only", figsize=(14.40, 9.00), dpi=100)
plt.plot(np.asarray(mod_mjd_list_i), np.asarray(x_i), 'r-', label = 'i_s')
ax = plt.gca() formy = plt.ScalarFormatter() formy.set_powerlimits((-5, 5))

formy.set_scientific(False)

ax.yaxis.set_major_formatter(formy)

 

Any ideas what I can do?

 

Thanks,

frix

 

 

Re: [Matplotlib-users] Plot resolution of axes

[Miriam D. <md...@am...>]

Hi Jon,

yes, this is what I am looking for. Now, the chart is like I've expected.

Thank you all! (...also for the quick response!)

Miriam D.


On 25/03/13 17:00, Jonathan Slavin wrote:
> Hi Miriam,
>
> This case is a simple one for setting the axis ratios.  You want to set
> the aspect ratio to equal:
> gca().set_aspect('equal')
> after making your plot
>
> Jon
>
> On Mon, 2013-03-25 at 16:06 +0100, Miriam Degginger wrote:
>> Hi all,
>>
>> I am working on a correlation chart with pyplot for a monitoring web
>> tool. The plot is looking good, but only the strange resolution of axes
>> disturbs the view.
>>
>> In a simple correlation plot, e.g. I want to compare two temperature
>> sensors, I expect a line who divides the picture in two halves with an
>> angle of 45° (optimal correlation R²=1). That feels natural and you can
>> see whether the both sensors correlate or not without a deeper look at
>> the exact values. But pyplot shows me a chart, where the x-axis's tick
>> interval is larger (108 pixel) than the y-axis's tick interval (77
>> pixel). In attachment you can see my example.
>>
>> How can I manipulate the axes that they show the same pixel resolution?
>>
>> I hope I make my case clear. If more information is needed, please tell me.
>>
>> Thank you very much in advance!
>>
>> Miriam D.

Re: [Matplotlib-users] Plot resolution of axes

[Jonathan S. <js...@cf...>]

Hi Miriam,

This case is a simple one for setting the axis ratios.  You want to set
the aspect ratio to equal:
gca().set_aspect('equal')
after making your plot

Jon

On Mon, 2013-03-25 at 16:06 +0100, Miriam Degginger wrote:
> Hi all,
> 
> I am working on a correlation chart with pyplot for a monitoring web 
> tool. The plot is looking good, but only the strange resolution of axes 
> disturbs the view.
> 
> In a simple correlation plot, e.g. I want to compare two temperature 
> sensors, I expect a line who divides the picture in two halves with an 
> angle of 45° (optimal correlation R²=1). That feels natural and you can 
> see whether the both sensors correlate or not without a deeper look at 
> the exact values. But pyplot shows me a chart, where the x-axis's tick 
> interval is larger (108 pixel) than the y-axis's tick interval (77 
> pixel). In attachment you can see my example.
> 
> How can I manipulate the axes that they show the same pixel resolution?
> 
> I hope I make my case clear. If more information is needed, please tell me.
> 
> Thank you very much in advance!
> 
> Miriam D.

-- 
______________________________________________________________
Jonathan D. Slavin              Harvard-Smithsonian CfA
js...@cf...         60 Garden Street, MS 83
phone: (617) 496-7981           Cambridge, MA 02138-1516
 cell: (781) 363-0035           USA
______________________________________________________________

Re: [Matplotlib-users] Plot resolution of axes

[Benjamin R. <ben...@ou...>]

On Mon, Mar 25, 2013 at 11:06 AM, Miriam Degginger <md...@am...> wrote:

> Hi all,
>
> I am working on a correlation chart with pyplot for a monitoring web tool.
> The plot is looking good, but only the strange resolution of axes disturbs
> the view.
>
> In a simple correlation plot, e.g. I want to compare two temperature
> sensors, I expect a line who divides the picture in two halves with an
> angle of 45° (optimal correlation R²=1). That feels natural and you can see
> whether the both sensors correlate or not without a deeper look at the
> exact values. But pyplot shows me a chart, where the x-axis's tick interval
> is larger (108 pixel) than the y-axis's tick interval (77 pixel). In
> attachment you can see my example.
>
> How can I manipulate the axes that they show the same pixel resolution?
>
> I hope I make my case clear. If more information is needed, please tell me.
>
> Thank you very much in advance!
>
> Miriam D.
>
>
Did you try:

ax.set_aspect('equal')

I don't know how you plotted your figure, so I don't know which matplotlib
objects you have at your disposal.  My above example would operate on the
Axes object returned by a call to add_subplot() or plt.subplot().

Cheers!
Ben Root

[Matplotlib-users] Plot resolution of axes

[Miriam D. <md...@am...>]

Hi all,

I am working on a correlation chart with pyplot for a monitoring web 
tool. The plot is looking good, but only the strange resolution of axes 
disturbs the view.

In a simple correlation plot, e.g. I want to compare two temperature 
sensors, I expect a line who divides the picture in two halves with an 
angle of 45° (optimal correlation R²=1). That feels natural and you can 
see whether the both sensors correlate or not without a deeper look at 
the exact values. But pyplot shows me a chart, where the x-axis's tick 
interval is larger (108 pixel) than the y-axis's tick interval (77 
pixel). In attachment you can see my example.

How can I manipulate the axes that they show the same pixel resolution?

I hope I make my case clear. If more information is needed, please tell me.

Thank you very much in advance!

Miriam D.

[Matplotlib-users] How to properly use path.Path.contains_point?

[Russell W. <ru...@pe...>]

I'm trying to use path.Path.contains_point for point-in-polygon testing and
am running into a few different confusing situations.  My specific
issues/questions are:

1. I'm seeing different behaviour dependent on path direction (clockwise or
counter-clockwise).  Is there a "correct" direction to use?

2. What is the expected behaviour for Path.contains_point when the point is
on a boundary?

3. What is the radius parameter supposed to do?  The docs say it "allows
the path to be made slightly larger or smaller", but I'm clearly not
understanding this properly (see the cw_path hit test failure with r=0.1
below).

Here is a short example showing some issues with a unit rectangle...

>>> from matplotlib.path import Path
>>> cw_path  = Path([[0,0], [0,1], [1,1], [1,0]])
>>> ccw_path = Path([[0,0], [1,0], [1,1], [0,1]])
>>> #Point on x axis not detected for either path...
... cw_path.contains_point([0.5, 0])
0
>>> ccw_path.contains_point([0.5, 0])
0
>>> #Add a large radius and ccw_path works, but not cw_path (!!?)...
... r = 0.1
>>> cw_path.contains_point([0.5, 0], radius=r)
0
>>> ccw_path.contains_point([0.5, 0], radius=r)
1

The following ipython notebook has more detailed tests, but the main points
are in the sample above.
http://nbviewer.ipython.org/7e1b347b8b21b338bee1

I've found at least one reference [1] online indicating that "this function
is intended for use when mouse-clicking".  Does that mean I should not use
it for generic point-in-polygon testing?

Thanks,
Russ

[1] http://goo.gl/GtVM6

Re: [Matplotlib-users] Squashed axes with AxesGrid

[Steven B. <bo...@ph...>]

Hey Jody et al.

Yeah aspect = False does the trick. Thanks for the help trouble 
shooting.

Steven

On Fri Mar 22 11:59:45 2013, Jody Klymak wrote:
> ...and did aspect=False not give you what you want?
>
>  From what I can see http://matplotlib.org/mpl_toolkits/axes_grid/users/overview.html#axes-grid1
>
> contradicts itself, and the chart is correct and the description below incorrect.
>
> FWIW, I would expect the default to be False as well, but who am I to say?
>
> Cheers,   Jody
>
> On Mar 22, 2013, at  9:52 AM, Steven Boada <bo...@ph...> wrote:
>
>> Sorry y'all. I can see the confusion.
>>
>> I started with AxesGrid -- squashed.
>>
>> JJ suggested Grid and that fixes the scaling problems.
>>
>> I realized that using just plain Grid doesn't give me the nice controls
>> over the colorbars (which I would like to have), so I wrote a simple
>> script and emailed it back out. That did include AxesGrid.
>>
>> According to the manual (
>> http://matplotlib.org/mpl_toolkits/axes_grid/users/overview.html#axes-grid1
>> )...
>>
>> aspect
>> By default (False), widths and heights of axes in the grid are scaled
>> independently. If True, they are scaled according to their data limits
>> (similar to aspect parameter in mpl).
>>
>> Which I read as it should scale the widths and heights should not be
>> squashed. But what Ben is telling me (thanks for the explanation) is
>> that isn't true. Seems like there is something simple I am just missing.
>>
>> Sorry for that bit of confusion.
>>
>> Steven
>>
>> On Fri Mar 22 11:39:46 2013, Benjamin Root wrote:
>>>
>>>
>>> On Fri, Mar 22, 2013 at 12:30 PM, Steven Boada <bo...@ph...
>>> <mailto:bo...@ph...>> wrote:
>>>
>>>     Well... I jumped the gun. To better illustrate the problem(s) I am
>>>     having, I wrote a simple script that doesn't work...
>>>
>>>     import pylab as pyl
>>>     from mpl_toolkits.axes_grid1 import AxesGrid
>>>
>>>     # make some data
>>>     xdata = pyl.random(100) * 25.
>>>     ydata = pyl.random(100) * 8.
>>>     colordata = pyl.random(100) * 3.
>>>
>>>     # make us a figure
>>>     F = pyl.figure(1,figsize=(5.5,3.5)__)
>>>     grid = AxesGrid(F, 111,
>>>             nrows_ncols=(1,2),
>>>             axes_pad = 0.1,
>>>             add_all=True,
>>>             share_all = True,
>>>             cbar_mode = 'each',
>>>             cbar_location = 'top')
>>>
>>>     # Plot!
>>>     sc1 = grid[0].scatter(xdata, ydata, c=colordata, s=50,
>>>     cmap='spectral')
>>>     sc2 = grid[1].scatter(xdata, ydata, c=colordata, s=50,
>>>     cmap='spectral')
>>>
>>>     # Add colorbars
>>>     grid.cbar_axes[0].colorbar(__sc1)
>>>     grid.cbar_axes[1].colorbar(__sc2)
>>>
>>>     grid[0].set_xlim(0,25)
>>>     grid[0].set_ylim(0,8)
>>>
>>>     pyl.show()
>>>
>>>
>>>     And you get some squashed figures... I'll attach a png.
>>>
>>>     Thanks again.
>>>
>>>     Steven
>>>
>>>
>>> You used AxesGrid again, not Grid.  AxesGrid implicitly applies an
>>> aspect='equal' to the subplots.  This means that a unit of distance on
>>> the x-axis takes the same amount of space as the same unit of distance
>>> on the y-axis.  In your example, the x axis goes from 0 to 25, while
>>> the y-axis goes from 0 to 8.  When aspect='equal', the y-axis will
>>> then be about a third the size of the x-axis, because the y-limits are
>>> about a third the size of the x-limits.
>>>
>>> Ben Root
>>>
>>
>> --
>>
>> Steven Boada
>>
>> Doctoral Student
>> Dept of Physics and Astronomy
>> Texas A&M University
>> bo...@ph...
>>
>> ------------------------------------------------------------------------------
>> Everyone hates slow websites. So do we.
>> Make your web apps faster with AppDynamics
>> Download AppDynamics Lite for free today:
>> http://p.sf.net/sfu/appdyn_d2d_mar
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
> --
> Jody Klymak
> http://web.uvic.ca/~jklymak/
>
>
>
>

--

Steven Boada

Doctoral Student
Dept of Physics and Astronomy
Texas A&M University
bo...@ph...

Re: [Matplotlib-users] Squashed axes with AxesGrid

[Jody K. <jk...@uv...>]

...and did aspect=False not give you what you want?  

From what I can see http://matplotlib.org/mpl_toolkits/axes_grid/users/overview.html#axes-grid1

contradicts itself, and the chart is correct and the description below incorrect.

FWIW, I would expect the default to be False as well, but who am I to say?

Cheers,   Jody

On Mar 22, 2013, at  9:52 AM, Steven Boada <bo...@ph...> wrote:

> Sorry y'all. I can see the confusion.
> 
> I started with AxesGrid -- squashed.
> 
> JJ suggested Grid and that fixes the scaling problems.
> 
> I realized that using just plain Grid doesn't give me the nice controls 
> over the colorbars (which I would like to have), so I wrote a simple 
> script and emailed it back out. That did include AxesGrid.
> 
> According to the manual ( 
> http://matplotlib.org/mpl_toolkits/axes_grid/users/overview.html#axes-grid1 
> )...
> 
> aspect
> By default (False), widths and heights of axes in the grid are scaled 
> independently. If True, they are scaled according to their data limits 
> (similar to aspect parameter in mpl).
> 
> Which I read as it should scale the widths and heights should not be 
> squashed. But what Ben is telling me (thanks for the explanation) is 
> that isn't true. Seems like there is something simple I am just missing.
> 
> Sorry for that bit of confusion.
> 
> Steven
> 
> On Fri Mar 22 11:39:46 2013, Benjamin Root wrote:
>> 
>> 
>> On Fri, Mar 22, 2013 at 12:30 PM, Steven Boada <bo...@ph...
>> <mailto:bo...@ph...>> wrote:
>> 
>>    Well... I jumped the gun. To better illustrate the problem(s) I am
>>    having, I wrote a simple script that doesn't work...
>> 
>>    import pylab as pyl
>>    from mpl_toolkits.axes_grid1 import AxesGrid
>> 
>>    # make some data
>>    xdata = pyl.random(100) * 25.
>>    ydata = pyl.random(100) * 8.
>>    colordata = pyl.random(100) * 3.
>> 
>>    # make us a figure
>>    F = pyl.figure(1,figsize=(5.5,3.5)__)
>>    grid = AxesGrid(F, 111,
>>            nrows_ncols=(1,2),
>>            axes_pad = 0.1,
>>            add_all=True,
>>            share_all = True,
>>            cbar_mode = 'each',
>>            cbar_location = 'top')
>> 
>>    # Plot!
>>    sc1 = grid[0].scatter(xdata, ydata, c=colordata, s=50,
>>    cmap='spectral')
>>    sc2 = grid[1].scatter(xdata, ydata, c=colordata, s=50,
>>    cmap='spectral')
>> 
>>    # Add colorbars
>>    grid.cbar_axes[0].colorbar(__sc1)
>>    grid.cbar_axes[1].colorbar(__sc2)
>> 
>>    grid[0].set_xlim(0,25)
>>    grid[0].set_ylim(0,8)
>> 
>>    pyl.show()
>> 
>> 
>>    And you get some squashed figures... I'll attach a png.
>> 
>>    Thanks again.
>> 
>>    Steven
>> 
>> 
>> You used AxesGrid again, not Grid.  AxesGrid implicitly applies an
>> aspect='equal' to the subplots.  This means that a unit of distance on
>> the x-axis takes the same amount of space as the same unit of distance
>> on the y-axis.  In your example, the x axis goes from 0 to 25, while
>> the y-axis goes from 0 to 8.  When aspect='equal', the y-axis will
>> then be about a third the size of the x-axis, because the y-limits are
>> about a third the size of the x-limits.
>> 
>> Ben Root
>> 
> 
> --
> 
> Steven Boada
> 
> Doctoral Student
> Dept of Physics and Astronomy
> Texas A&M University
> bo...@ph...
> 
> ------------------------------------------------------------------------------
> Everyone hates slow websites. So do we.
> Make your web apps faster with AppDynamics
> Download AppDynamics Lite for free today:
> http://p.sf.net/sfu/appdyn_d2d_mar
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

--
Jody Klymak    
http://web.uvic.ca/~jklymak/

Re: [Matplotlib-users] Squashed axes with AxesGrid

[Steven B. <bo...@ph...>]

Sorry y'all. I can see the confusion.

I started with AxesGrid -- squashed.

JJ suggested Grid and that fixes the scaling problems.

I realized that using just plain Grid doesn't give me the nice controls 
over the colorbars (which I would like to have), so I wrote a simple 
script and emailed it back out. That did include AxesGrid.

According to the manual ( 
http://matplotlib.org/mpl_toolkits/axes_grid/users/overview.html#axes-grid1 
)...

aspect
By default (False), widths and heights of axes in the grid are scaled 
independently. If True, they are scaled according to their data limits 
(similar to aspect parameter in mpl).

Which I read as it should scale the widths and heights should not be 
squashed. But what Ben is telling me (thanks for the explanation) is 
that isn't true. Seems like there is something simple I am just missing.

Sorry for that bit of confusion.

Steven

On Fri Mar 22 11:39:46 2013, Benjamin Root wrote:
>
>
> On Fri, Mar 22, 2013 at 12:30 PM, Steven Boada <bo...@ph...
> <mailto:bo...@ph...>> wrote:
>
>     Well... I jumped the gun. To better illustrate the problem(s) I am
>     having, I wrote a simple script that doesn't work...
>
>     import pylab as pyl
>     from mpl_toolkits.axes_grid1 import AxesGrid
>
>     # make some data
>     xdata = pyl.random(100) * 25.
>     ydata = pyl.random(100) * 8.
>     colordata = pyl.random(100) * 3.
>
>     # make us a figure
>     F = pyl.figure(1,figsize=(5.5,3.5)__)
>     grid = AxesGrid(F, 111,
>             nrows_ncols=(1,2),
>             axes_pad = 0.1,
>             add_all=True,
>             share_all = True,
>             cbar_mode = 'each',
>             cbar_location = 'top')
>
>     # Plot!
>     sc1 = grid[0].scatter(xdata, ydata, c=colordata, s=50,
>     cmap='spectral')
>     sc2 = grid[1].scatter(xdata, ydata, c=colordata, s=50,
>     cmap='spectral')
>
>     # Add colorbars
>     grid.cbar_axes[0].colorbar(__sc1)
>     grid.cbar_axes[1].colorbar(__sc2)
>
>     grid[0].set_xlim(0,25)
>     grid[0].set_ylim(0,8)
>
>     pyl.show()
>
>
>     And you get some squashed figures... I'll attach a png.
>
>     Thanks again.
>
>     Steven
>
>
> You used AxesGrid again, not Grid.  AxesGrid implicitly applies an
> aspect='equal' to the subplots.  This means that a unit of distance on
> the x-axis takes the same amount of space as the same unit of distance
> on the y-axis.  In your example, the x axis goes from 0 to 25, while
> the y-axis goes from 0 to 8.  When aspect='equal', the y-axis will
> then be about a third the size of the x-axis, because the y-limits are
> about a third the size of the x-limits.
>
> Ben Root
>

--

Steven Boada

Doctoral Student
Dept of Physics and Astronomy
Texas A&M University
bo...@ph...