matplotlib-users Mailing List for matplotlib (Page 2)

On Fri, Feb 18, 2011 at 9:13 AM, JamesTan12 <lan...@ho...> wrote:

>
> Hi I have a list (Key values) with values I would like to plot to a
> matplotlib histogram
>
> [('a', 155), ('c', 73), ('b', 19), ('e', 260), ('d', 73), ('g', 42), ('f',
> 47), ('i', 175), ('h', 77), ('k', 7), ('j', 2), ('m', 76), ('l', 63), ('o',
> 174), ('n', 145), ('q', 3), ('p', 61), ('s', 153), ('r', 143), ('u', 50),
> ('t', 193), ('w', 19), ('v', 21), ('y', 55), ('x', 4), ('z', 4)]
>
> Can anyone suggest how do I go about to plot it into a histogram with
> x-asix
> being the key and y axis being the value.?
>

I would do something like the following:

data = [('a', 155), ('c', 73), ('b', 19), ('e', 260), ('d', 73), ('g', 42),
('f',
47), ('i', 175), ('h', 77), ('k', 7), ('j', 2), ('m', 76), ('l', 63), ('o',
174), ('n', 145), ('q', 3), ('p', 61), ('s', 153), ('r', 143), ('u', 50),
('t', 193), ('w', 19), ('v', 21), ('y', 55), ('x', 4), ('z', 4)]

x, y = zip(*data)
xlocs = np.arange(len(x))

fig = plt.figure()
ax = fig.gca()
ax.bar(xlocs + 0.6, y)
ax.set_xticks(xlocs + 1)
ax.set_xticklabels(x)
ax.set_xlim(0.0, xlocs.max() + 2)

plt.show()


The xlocs + 0.6 is to list the left edge of the bars so that they are
centered on integer tick locations (the bars are 0.8 wide by default).  The
xlocs + 1 is to set the xaxis ticks at the center of each bar, and the
xlocs.max() + 2 is to have enough room on the right hand side of your graph
for everything.

I hope that helps!

Ben Root

2011/2/18 Jason Stone <sto...@gm...>

> Good afternoon all,
> I'm developing a GUI using QT Designer 4 and Python 2.7.  The GUI will need
> to have several plots on it in order to show the data in the ways that I
> need.  To accomplish this I'm using the matplotlib widget from within QT
> Designer.  It all seems to work great, but I can't seem to find a way to
> change the background color of the widget.  Essentially, I've got a nicely
> laid out GUI with the default QT Designer light gray as the "background
> color".  Then I've got these matplotlib widgets which by default have a
> darker shade of gray/charcoal as their "background color".  How do I change
> the matplotlib widget bgcolor to the default light gray so as to match the
> rest of the GUI?  Turning the background of the main GUI to the dark gray to
> match the matplotlib color is not an option.  I kind of assumed the issue
> has to do with the matplotlib widget and not with QT Designer, hence the
> reason for posting in this mailing list.
>
> Does anyone have any thoughts regarding this?  Or can you point me to a
> documentation set that shows how to do this?
>

this<http://matplotlib.sourceforge.net/faq/howto_faq.html?highlight=codex%20transparent#save-transparent-figures>could
help you.

and it is named *Qt*.
QT means quicktime.

On 2/22/2011 7:47 AM, Waléria Antunes David wrote:
> I tried what Ben said: ax.set_ylim(bottom=1) ..., but changed nothing.

Put it last, *after* all plotting.

And since you won't be able to see your green line,
don't plot it.

First, the python3k branch is completely experimental and only about 10% 
complete.  If your expectation is to have something that just works, 
you'll want to wait a while.  We're hoping to hold a sprint next month 
to make some more progress on it.  If you're hoping to help us out with 
it, great!

You'll want to check out from the new git repository here:

https://github.com/matplotlib/matplotlib-py3



On 02/22/2011 03:52 AM, Markus1234 wrote:
> Hello everyone,
>
> I tried to build
> http://matplotlib.svn.sourceforge.net/viewvc/matplotlib/branches/py3k/ with
> Python 3.1.3 and get the following error message (whole output in the
> attachement)
>
> In file included from CXX\IndirectPythonInterface.cxx:42:0:
> CXX\/Python3/IndirectPythonInterface.cxx: In function 'PyObject*
> Py::_Exc_MemoryErrorInst()':
> CXX\/Python3/IndirectPythonInterface.cxx:452:50: error:
> '::PyExc_MemoryErrorInst' has not been declared
> CXX\/Python3/IndirectPythonInterface.cxx:452:75: warning: control reaches
> end of non-void function
> error: command 'gcc' failed with exit status 1
What platform/compiler are you on?  I haven't seen this, but we've only 
worked the py3k branch on Linux so far.
> Also can anyone help me how to 'correctly' configure freetypes2. I
> downloaded and installed it and copied part of it from /Program
> Files/GnuWin32/src/freetype/2.3.5/freetype-2.3.5\/include to
> py3k/freetypes2/
> Is there a more elegant way to configure the setup correctly?
Normally, in Unixy land "make install" would install the headers to 
/usr/local/include and the matplotlib build would pick them up there.  
Not sure how things are supposed to work in the GnuWin32 environment, 
though.

Mike
> Best regards,
>
> Markus http://old.nabble.com/file/p30947414/output.txt output.txt

Daniel,

Thank you very much....the yscale is correct now.....this topic is
resolved...

Thanks....

On Tue, Feb 22, 2011 at 10:26 AM, Daniel Mader <
dan...@go...> wrote:

> Hi Waléria,
>
> in order to test it and help you without spending too much time on it,
> could you please provide a stripped example which runs standalone?
>
> As a general rule you should set limits at the very end of the
> plotting code in order to prevent them from being superseded by
> another command!
>
> Thanks,
> Daniel
>
> 2011/2/22 Waléria Antunes David <wal...@gm...>:
> > I tried what Ben said: ax.set_ylim(bottom=1) ..., but changed nothing.
> See
> > my code: http://pastebin.com/Jt3BTp0C (line 14)
> >
> > See my image generated - attached.
> >
> > thanks,
> >
> > On Tue, Feb 22, 2011 at 9:37 AM, Mike Kaufman <mc...@gm...> wrote:
> >>
> >> send me your data.
> >>
> >> M
> >>
> >> On 2/22/11 6:29 AM, Waléria Antunes David wrote:
> >>>
> >>> See this pdf attached....the yscale has these values: 1, 10, 100, 1000
> >>> ....I need this. My code: http://pastebin.com/HKCGQWez
> >>> Can you help me, please??
> >>>
> >>> Thanks,
> >>>
> >>> On Mon, Feb 21, 2011 at 4:41 PM, Benjamin Root <ben...@ou...
> >>> <mailto:ben...@ou...>> wrote:
> >>>
> >>>
> >>>
> >>>    On Mon, Feb 21, 2011 at 1:32 PM, Waléria Antunes David
> >>>    <wal...@gm... <mailto:wal...@gm...>> wrote:
> >>>
> >>>        Can you help me...please.
> >>>
> >>>        On Mon, Feb 21, 2011 at 4:02 PM, Waléria Antunes David
> >>>        <wal...@gm... <mailto:wal...@gm...>>
> wrote:
> >>>
> >>>            I don't understand...i need that the yscale has these
> >>>            values: 1,10,100,1000 ....But i don't know how...
> >>>
> >>>            Thanks,
> >>>
> >>>
> >>>
> >>>    Let me make it clearer.  Your green line has values on the order of
> >>>    10^-17.  There is nothing that can be done to meet your request if
> >>>    you are plotting data this small.  Either this data is wrong, or you
> >>>    don't want to plot it at all.
> >>>
> >>>    To exclude anything less than 1, use the following:
> >>>
> >>>    ax.set_ylim(bottom=1)
> >>>
> >>>    Note that this will exclude the green line in your plot!
> >>>
> >>>    Ben Root
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> ------------------------------------------------------------------------------
> >>> Index, Search&  Analyze Logs and other IT data in Real-Time with Splunk
> >>> Collect, index and harness all the fast moving IT data generated by
> your
> >>> applications, servers and devices whether physical, virtual or in the
> >>> cloud.
> >>> Deliver compliance at lower cost and gain new business insights.
> >>> Free Software Download: http://p.sf.net/sfu/splunk-dev2dev
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> Matplotlib-users mailing list
> >>> Mat...@li...
> >>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> >>
> >
> >
> >
> ------------------------------------------------------------------------------
> > Index, Search & Analyze Logs and other IT data in Real-Time with Splunk
> > Collect, index and harness all the fast moving IT data generated by your
> > applications, servers and devices whether physical, virtual or in the
> cloud.
> > Deliver compliance at lower cost and gain new business insights.
> > Free Software Download: http://p.sf.net/sfu/splunk-dev2dev
> > _______________________________________________
> > Matplotlib-users mailing list
> > Mat...@li...
> > https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> >
> >
>

Hi Waléria,

in order to test it and help you without spending too much time on it,
could you please provide a stripped example which runs standalone?

As a general rule you should set limits at the very end of the
plotting code in order to prevent them from being superseded by
another command!

Thanks,
Daniel

2011/2/22 Waléria Antunes David <wal...@gm...>:
> I tried what Ben said: ax.set_ylim(bottom=1) ..., but changed nothing. See
> my code: http://pastebin.com/Jt3BTp0C (line 14)
>
> See my image generated - attached.
>
> thanks,
>
> On Tue, Feb 22, 2011 at 9:37 AM, Mike Kaufman <mc...@gm...> wrote:
>>
>> send me your data.
>>
>> M
>>
>> On 2/22/11 6:29 AM, Waléria Antunes David wrote:
>>>
>>> See this pdf attached....the yscale has these values: 1, 10, 100, 1000
>>> ....I need this. My code: http://pastebin.com/HKCGQWez
>>> Can you help me, please??
>>>
>>> Thanks,
>>>
>>> On Mon, Feb 21, 2011 at 4:41 PM, Benjamin Root <ben...@ou...
>>> <mailto:ben...@ou...>> wrote:
>>>
>>>
>>>
>>>    On Mon, Feb 21, 2011 at 1:32 PM, Waléria Antunes David
>>>    <wal...@gm... <mailto:wal...@gm...>> wrote:
>>>
>>>        Can you help me...please.
>>>
>>>        On Mon, Feb 21, 2011 at 4:02 PM, Waléria Antunes David
>>>        <wal...@gm... <mailto:wal...@gm...>> wrote:
>>>
>>>            I don't understand...i need that the yscale has these
>>>            values: 1,10,100,1000 ....But i don't know how...
>>>
>>>            Thanks,
>>>
>>>
>>>
>>>    Let me make it clearer.  Your green line has values on the order of
>>>    10^-17.  There is nothing that can be done to meet your request if
>>>    you are plotting data this small.  Either this data is wrong, or you
>>>    don't want to plot it at all.
>>>
>>>    To exclude anything less than 1, use the following:
>>>
>>>    ax.set_ylim(bottom=1)
>>>
>>>    Note that this will exclude the green line in your plot!
>>>
>>>    Ben Root
>>>
>>>
>>>
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> Index, Search&  Analyze Logs and other IT data in Real-Time with Splunk
>>> Collect, index and harness all the fast moving IT data generated by your
>>> applications, servers and devices whether physical, virtual or in the
>>> cloud.
>>> Deliver compliance at lower cost and gain new business insights.
>>> Free Software Download: http://p.sf.net/sfu/splunk-dev2dev
>>>
>>>
>>>
>>> _______________________________________________
>>> Matplotlib-users mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>
>
>
> ------------------------------------------------------------------------------
> Index, Search & Analyze Logs and other IT data in Real-Time with Splunk
> Collect, index and harness all the fast moving IT data generated by your
> applications, servers and devices whether physical, virtual or in the cloud.
> Deliver compliance at lower cost and gain new business insights.
> Free Software Download: http://p.sf.net/sfu/splunk-dev2dev
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>

Do you want my complete code?

Thanks,

On Tue, Feb 22, 2011 at 10:17 AM, Mike Kaufman <mc...@gm...> wrote:

> Look, something about your dataset is most likely causing this problem.
> Send me the 5 data series you are using for this code, and I will attempt to
> reproduce the plot (and then show you how I did it).
>
> M
>
>
> On 2/22/11 7:47 AM, Waléria Antunes David wrote:
>
>> I tried what Ben said: ax.set_ylim(bottom=1) ..., but changed nothing.
>> See my code: http://pastebin.com/Jt3BTp0C (line 14)
>>
>> See my image generated - attached.
>>
>> thanks,
>>
>> On Tue, Feb 22, 2011 at 9:37 AM, Mike Kaufman <mc...@gm...
>> <mailto:mc...@gm...>> wrote:
>>
>>    send me your data.
>>
>>    M
>>
>>
>>    On 2/22/11 6:29 AM, Waléria Antunes David wrote:
>>
>>        See this pdf attached....the yscale has these values: 1, 10,
>>        100, 1000
>>        ....I need this. My code: http://pastebin.com/HKCGQWez
>>        Can you help me, please??
>>
>>        Thanks,
>>
>>        On Mon, Feb 21, 2011 at 4:41 PM, Benjamin Root <ben...@ou...
>>        <mailto:ben...@ou...>
>>        <mailto:ben...@ou... <mailto:ben...@ou...>>> wrote:
>>
>>
>>
>>            On Mon, Feb 21, 2011 at 1:32 PM, Waléria Antunes David
>>        <wal...@gm... <mailto:wal...@gm...>
>>        <mailto:wal...@gm...
>>
>>        <mailto:wal...@gm...>>> wrote:
>>
>>                Can you help me...please.
>>
>>                On Mon, Feb 21, 2011 at 4:02 PM, Waléria Antunes David
>>        <wal...@gm... <mailto:wal...@gm...>
>>        <mailto:wal...@gm...
>>
>>        <mailto:wal...@gm...>>> wrote:
>>
>>                    I don't understand...i need that the yscale has these
>>                    values: 1,10,100,1000 ....But i don't know how...
>>
>>                    Thanks,
>>
>>
>>
>>            Let me make it clearer.  Your green line has values on the
>>        order of
>>            10^-17.  There is nothing that can be done to meet your
>>        request if
>>            you are plotting data this small.  Either this data is
>>        wrong, or you
>>            don't want to plot it at all.
>>
>>            To exclude anything less than 1, use the following:
>>
>>            ax.set_ylim(bottom=1)
>>
>>            Note that this will exclude the green line in your plot!
>>
>>            Ben Root
>>
>>
>>
>>
>>
>>  ------------------------------------------------------------------------------
>>        Index, Search&  Analyze Logs and other IT data in Real-Time with
>>        Splunk
>>        Collect, index and harness all the fast moving IT data generated
>>        by your
>>        applications, servers and devices whether physical, virtual or
>>        in the cloud.
>>        Deliver compliance at lower cost and gain new business insights.
>>        Free Software Download: http://p.sf.net/sfu/splunk-dev2dev
>>
>>
>>
>>        _______________________________________________
>>        Matplotlib-users mailing list
>>        Mat...@li...
>>        <mailto:Mat...@li...>
>>
>>        https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>
>>
>>
>>
>

Can you provide us with your script ?
 
Thomas

**********************
Thomas Lecocq 
Geologist
Ph.D.Student (Seismology)
Royal Observatory of Belgium
**********************


 
> From: cb...@oz...
> Date: Tue, 22 Feb 2011 21:05:48 +1100
> To: mat...@li...
> Subject: [Matplotlib-users] Can't produce plots using Matplotlib
> 
> Recently I downloaded and installed Python(x,y) Version 2.6.5.6 running under Windows7 and now can't produce the plots that my programs produced under an earlier version of Python(x,y). The programs seem to run correctly and produce the same numerical results but I can't find the graphical output (if it exists).
> I presume that the problem isn caused by either an incorrect use of Matplotlib, an installation issue or my simply misunderstanding the use of Spyder.
> I would greatly appreciate some guidance on how to solve this problem.
> ------------------------------------------------------------------------------
> Index, Search & Analyze Logs and other IT data in Real-Time with Splunk 
> Collect, index and harness all the fast moving IT data generated by your 
> applications, servers and devices whether physical, virtual or in the cloud.
> Deliver compliance at lower cost and gain new business insights. 
> Free Software Download: http://p.sf.net/sfu/splunk-dev2dev
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
 		 	   		  

Recently I downloaded and installed Python(x,y) Version 2.6.5.6 running under Windows7 and now can't produce the plots that my programs produced under an earlier version of Python(x,y). The programs seem to run correctly and produce the same numerical results but I can't find the graphical output (if it exists).
I presume that the problem isn caused by either an incorrect use of Matplotlib, an installation issue or my simply misunderstanding the use of Spyder.
I would greatly appreciate some guidance on how to solve this problem.

Hi,

there has been a similar question recently but I couldn't figure out
if or how this is solved:

I'd like to reduce the figure size so that I can add it to a LaTeX
document without scaling (PDF output with LaTeX font rendering). For
that, I need to adapt the font sizes, too.

Unfortunately, the canvas is not properly scaled so that the axis
labels and the possibly the tick marks are cut off.

Is this a bug, feature, design flaw? How can I properly work around
it, i.e. reduce the graph automatically for a given figsize/font size
combination so that everything fits on the figure?

An example follows to demonstrate, thanks in advance,
Daniel

import numpy,pylab,matplotlib.ticker as mtick

x = numpy.linspace(0,10,1000)
y = numpy.exp(x)

pylab.rcdefaults()

fig = pylab.figure()
ax = fig.add_subplot(111)
ax.set_yscale('log')
ax.yaxis.set_major_formatter(mtick.FormatStrFormatter('%d'))
ax.set_xlabel('asdf')
ax.set_ylabel('qwer')
ax.plot(x,y)
fig.savefig('example_mpl-ticker_1')

pylab.rcParams['figure.figsize'] = 5,3
pylab.rcParams['font.size'] = 12

fig = pylab.figure()
ax = fig.add_subplot(111)
ax.set_yscale('log')
ax.yaxis.set_major_formatter(mtick.FormatStrFormatter('%d'))
ax.set_xlabel('asdf')
ax.set_ylabel('qwer')
ax.plot(x,y)
fig.savefig('example_mpl-ticker_2')

Hello everyone,

I tried to build
http://matplotlib.svn.sourceforge.net/viewvc/matplotlib/branches/py3k/ with
Python 3.1.3 and get the following error message (whole output in the
attachement)

In file included from CXX\IndirectPythonInterface.cxx:42:0:
CXX\/Python3/IndirectPythonInterface.cxx: In function 'PyObject*
Py::_Exc_MemoryErrorInst()':
CXX\/Python3/IndirectPythonInterface.cxx:452:50: error:
'::PyExc_MemoryErrorInst' has not been declared
CXX\/Python3/IndirectPythonInterface.cxx:452:75: warning: control reaches
end of non-void function
error: command 'gcc' failed with exit status 1

Also can anyone help me how to 'correctly' configure freetypes2. I
downloaded and installed it and copied part of it from /Program
Files/GnuWin32/src/freetype/2.3.5/freetype-2.3.5\/include to
py3k/freetypes2/
Is there a more elegant way to configure the setup correctly?

Best regards,

Markus http://old.nabble.com/file/p30947414/output.txt output.txt 
-- 
View this message in context: http://old.nabble.com/Building-matplotlib-py3k-branch-error-tp30947414p30947414.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

On 02/21/2011 07:27 PM, Zhaoru Zhang wrote:
> Hi,
>
>    I tried to use contourf to plot an array in which the land values have been masked. However, I found that contourf did not deal with the masking properly. I would expect the masked region to be bounded by the separation line of land and sea, but it actually exceeds that line. I also tried with pcolor and this time the masking is handled correctly. Could anybody tell me what is the right way to use contourf for plotting masked arrays? Thanks!
>

What mpl version are you using?  For a long time there was a deep-seated 
bug in handling masked regions, but about a year ago Ian Thomas fixed it.

Eric


> Zhaoru
> ------------------------------------------------------------------------------
> Index, Search&  Analyze Logs and other IT data in Real-Time with Splunk
> Collect, index and harness all the fast moving IT data generated by your
> applications, servers and devices whether physical, virtual or in the cloud.
> Deliver compliance at lower cost and gain new business insights.
> Free Software Download: http://p.sf.net/sfu/splunk-dev2dev
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

Hi,
 
  I tried to use contourf to plot an array in which the land values have been masked. However, I found that contourf did not deal with the masking properly. I would expect the masked region to be bounded by the separation line of land and sea, but it actually exceeds that line. I also tried with pcolor and this time the masking is handled correctly. Could anybody tell me what is the right way to use contourf for plotting masked arrays? Thanks!

Zhaoru

Can anyone help me understand this: the code below produces a plot in 
which the x and y axis labels are reversed relative to the direction in 
which z varies on the plot, although the gradient arrows are correctly 
oriented. Is there something I've missed in understanding the sense of 
the x and y directions in mgrid, imshow, and gradient?

"""
x,y axes seem to be reversed
"""
import numpy as np

from matplotlib.pylab import *

dx = .25; dy = .25

xlen = 2.0; ylen = 2.0

x,y = np.mgrid[-xlen:xlen:dx, -ylen:ylen:dy] #also works with ogrid

z = x

hold(True)

imshow(z, origin='lower', extent=[-xlen,xlen,-ylen,ylen])

colorbar()

[u,v] = np.gradient(z)

u /= dx; v /= dy

QP = quiver(x,y,u,v,pivot='middle',color=[0.5,0.5,0.5])

quiverkey(QP, 0.85, 1.05, 1.0, '1 unit', labelpos='N')

xlabel('x')

ylabel('y')

title('slope')

show()

2011/2/20 Curiouslearn <cur...@gm...>:
> Thomas and Goyo,
>
> Thanks for the answers. I am fine with them being coverted to ints. In
> fact, my ax.set_ylim(bottom=0, top=6000) contains ints and I don't
> understand why they are converted to floats. I was thinking that there
> is perhaps another (more correct) way to set tick values.

You can use locators, but set_yticks is good enough for simple cases.
http://matplotlib.sourceforge.net/api/ticker_api.html