matplotlib-users Mailing List for matplotlib

When using the Qt4 backend, I'm getting an IOError similar to the one
detailed in:
http://old.nabble.com/matplotlib-with-Qt4-backend-td26311369.html
But it's definitely a separate issue (see Traceback below). This issue also
seems specific to Qt (I couldn't reproduce it on 'macosx', 'tkagg', or 'agg'
backends).

I found a number of other people who ran into similar problems with Qt.
Their solutions tend to be: catch the error and just try running the process
again.

I'm on Qt 4.7.3, OS X 10.6.8, Matplotlib trunk. Any help would be much
appreciated.

-Tony


Script reproducing issue
========================
import matplotlib
matplotlib.use('qt4agg')
import matplotlib.pyplot as plt

for n in xrange(300):
    plt.plot([0, 1])
    plt.savefig('test.jpg')
# Since it's a signaling issue, it gets triggered randomly, so the attached
# script may or not reproduce the issue.

Traceback
=========

traceback (most recent call last):
  File "qterror.py", line 8, in <module>
    plt.savefig('test.jpg')
  File "/Users/Tony/python/devel/mpl/lib/matplotlib/pyplot.py", line 428, in
savefig
    return fig.savefig(*args, **kwargs)
  File "/Users/Tony/python/devel/mpl/lib/matplotlib/figure.py", line 1162,
in savefig

    self.canvas.print_figure(*args, **kwargs)
  File
"/Users/Tony/python/devel/mpl/lib/matplotlib/backends/backend_qt4agg.py",
line
 153, in print_figure
    FigureCanvasAgg.print_figure(self, *args, **kwargs)
  File "/Users/Tony/python/devel/mpl/lib/matplotlib/backend_bases.py", line
1979, in
print_figure
    **kwargs)
  File "/Users/Tony/python/devel/mpl/lib/matplotlib/backend_bases.py", line
1799, in
print_jpg
    buf, size = agg.print_to_buffer()
  File
"/Users/Tony/python/devel/mpl/lib/matplotlib/backends/backend_agg.py", line
45
7, in print_to_buffer
    FigureCanvasAgg.draw(self)
  File
"/Users/Tony/python/devel/mpl/lib/matplotlib/backends/backend_agg.py", line
40
0, in draw
    self.renderer = self.get_renderer()
  File
"/Users/Tony/python/devel/mpl/lib/matplotlib/backends/backend_agg.py", line
41
1, in get_renderer
    self.renderer = RendererAgg(w, h, self.figure.dpi)
  File
"/Users/Tony/python/devel/mpl/lib/matplotlib/backends/backend_agg.py", line
51
, in __init__
    RendererBase.__init__(self)
  File "/Users/Tony/python/devel/mpl/lib/matplotlib/backend_bases.py", line
114, in _
_init__
    self._text2path = textpath.TextToPath()
  File "/Users/Tony/python/devel/mpl/lib/matplotlib/textpath.py", line 37,
in __init_
_
    self._adobe_standard_encoding = self._get_adobe_standard_encoding()
  File "/Users/Tony/python/devel/mpl/lib/matplotlib/textpath.py", line 41,
in _get_ad
obe_standard_encoding
    enc_name = dviread.find_tex_file('8a.enc')
  File "/Users/Tony/python/devel/mpl/lib/matplotlib/dviread.py", line 837,
in find_te
x_file
    result = pipe.communicate()[0].rstrip()
  File
"/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/subpro
cess.py", line 663, in communicate
    stdout = self.stdout.read()
IOError: [Errno 4] Interrupted system call

Thanks for the report.  I have created a pull request with a solution 
for this bug here:

https://github.com/matplotlib/matplotlib/pull/403

If you are able to build from git, test these changes and give me 
feedback in your specific environment, that would be great.

Cheers,
Mike

On 07/14/2011 04:59 PM, Christopher Brown wrote:
> Hi,
>
> The following code displays a figure with both a red and a blue arrow
> (generated by annotate). But the pdf that is saved only shows the red
> one. It seems that the line ax1.set_xscale('log') is causing the
> trouble, because if it is commented out, the blue arrow reappears in the
> pdf. Any hints?
>
> import numpy as np
> from matplotlib import pyplot as pp
>
> fig = pp.figure()
> ax2 = fig.add_subplot(111)
> ax1 = ax2.twinx()
> ax1.set_xlim(xmin=100,xmax=10000)
> ax1.set_ylim(ymin=-60, ymax=5)
> ax1.set_xscale('log')
> ax2.set_xlim(xmin=100,xmax=10000)
> ax2.set_ylim(ymin=-5,ymax=35)
> ax2.set_xscale('log')
>
> ax1.annotate("", (10000,-30), (2000,-30),
>                arrowprops=dict(arrowstyle="-|>",fc="b", ec="b"))
> ax2.annotate("", (100, 5), (2000, 5),
>                arrowprops=dict(arrowstyle="-|>",fc="r", ec="r"))
> pp.savefig('test_arrow.pdf')
> pp.show()
>


-- 
Michael Droettboom
Science Software Branch
Space Telescope Science Institute
Baltimore, Maryland, USA

On Mon, Jul 18, 2011 at 10:58 AM, Daniel Mader
<dan...@go...> wrote:
> Hi,
>
> why don't you just parse the returned string?
>
> asdf = '3:04:02.994000'
> asdf = asdf.split(':')
> temp = asdf[-1].split('.')
> print asdf
> asdf.pop(-1)
> print asdf
> asdf.extend(temp)
> print asdf
> asdf = [int(i) for i in asdf]
> print asdf
> hrs,mins,secs,usecs = asdf
>
> That should work, and you can always transform this into some common
> unit, e.g. seconds etc.

Thanks.  The issue, though is that I don't want to display a graph
with seconds, but with whatever units is most suitable, since my data
is going to range from seconds to hours.  If most datapoints are
hours, I don't want things expressed in terms of "5000 seconds".

I thought there might be a way to use a DateLocator or DateFormatter
with this kind of data so that it could pick the most suitable units
based on a standardized time duration string.

So do people think I have to create my own custom locator or formatter
to do this?

Thanks,
Che

Hi everyone

I needed some help to make my output subplot made with the code below,
become something like this:
http://old.nabble.com/file/p32084025/Concentracao%2BFiltradoHbO%252CHbR%252CHbT%2BApneia_01.gif 


The code i used to this is here, tried to comment it alot, if u dont get
something, just ask..


Thanks alot for the help.... (the figure was hand-made, cept the plots)..


Heres the code:

def pltcanal(b, self):
##b=Matrix of dimensions (len(t),c) to plot x t
    t=d1.t
    idx1=0
    c = len(find( self.ml[:,3]==1 ))#just something from my code to make
sure we have the lenght of the matrix

    from scipy.stats import scoreatpercentile#To adjust the scales
    ymin1 = median(scoreatpercentile(d1.DOD[:,:27],0.05))
    ymin2 = median(scoreatpercentile(d1.DOD[:,27:],0.05))
    ymax1 = median(scoreatpercentile(d1.DOD[:,:27],99.95))
    ymax2 = median(scoreatpercentile(d1.DOD[:,27:],99.95))

    for idx1 in range(c):#making the subplots
        idx2=c+idx1
        subplot(c,2,2*idx1+1)
        plt.plot(t,b[:,idx1],color='g')
        ylim(ymin1,ymax1)
        frame1 = plt.gca()
        for xlabel_i in frame1.axes.get_xticklabels():#To remove the scales
            xlabel_i.set_visible(False)
            xlabel_i.set_fontsize(0.0)
        for xlabel_i in frame1.axes.get_yticklabels():
            xlabel_i.set_fontsize(0.0)
            xlabel_i.set_visible(False)
            
        subplot(c,2,2*idx1+2)
        plt.plot(t,b[:,idx2], color='r')
        ylim(ymin2,ymax2)
        frame1 = plt.gca()
        for xlabel_i in frame1.axes.get_xticklabels():
            xlabel_i.set_visible(False)
            xlabel_i.set_fontsize(0.0)
        for xlabel_i in frame1.axes.get_yticklabels():
            xlabel_i.set_fontsize(0.0)
            xlabel_i.set_visible(False)
-- 
View this message in context: http://old.nabble.com/Plotting-Scales-and-Tittles-on-Subplots-with-matplotlib-tp32084025p32084025.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Hi,

why don't you just parse the returned string?

asdf = '3:04:02.994000'
asdf = asdf.split(':')
temp = asdf[-1].split('.')
print asdf
asdf.pop(-1)
print asdf
asdf.extend(temp)
print asdf
asdf = [int(i) for i in asdf]
print asdf
hrs,mins,secs,usecs = asdf

That should work, and you can always transform this into some common
unit, e.g. seconds etc.

Hope it helps,
Daniel

2011/7/17 C M <cmp...@gm...>:
> This a time duration in my database:  '3:04:02.994000' (i.e., 3 hrs, 4
> min, 2 sec and 994 microsec).  It's a string.
>
> Is there a way to allow Matplotlib to interpret that directly as a
> duration of time?
>
> Thank you.

On 07/18/2011 01:03 PM, Eric Firing wrote:
> On 07/17/2011 03:47 PM, r-w wrote:
>> >  I have been able to embed a matplotlib simple line graph into a wxpython
>> >  application and then dynamically update the underlying line data.
>> >
>> >  However, I now want to do something similar with an errorbar plot. I see
>> >  that the errorbar() call returns (/plotline/,/caplines/,/barlinecols/)
>> >  where 'plotline' describes the line part of the plot and the 'caplines'
>> >  and 'barlinecols' describe the error bars and use the Path object.
>> >
>> >  I just can't see how to change the values underlying the errorbars. I
>> >  need to change the x and y values as well as the yerr values.
>> >
>> >  Anybody have any idea how to do this? Or should I look at other
>> >  approaches, such a simple line graph and a patch that draws error bars
>> >  'by hand'?
> If you need to update everything, then you probably can't do much better
> than to simply clear the axes and call the errorbar method each time you
> need to update.  That is certainly the easy way--you might as well try
> it first.
>
> Eric
>
Thanks for the tip Eric.  It would work but I probably don't want to go 
that way as the application I'm working on will have up to 25 line plots 
as well as other adornments.  But your suggestion lead me to another 
approach - put errorbars on a graph as a patch and remove the patch and 
create a new patch whenever the errorbar data changes.

I got most of the patch code from the tutorial:
http://matplotlib.sourceforge.net/users/path_tutorial.html

A working example is at:
http://pastebin.com/KMzzFTCi

Not sure if the above approach will work in my 'production' widget, but 
I'm on my way!

Thanks,
Ross

On 07/17/2011 03:47 PM, r-w wrote:
> I have been able to embed a matplotlib simple line graph into a wxpython
> application and then dynamically update the underlying line data.
>
> However, I now want to do something similar with an errorbar plot. I see
> that the errorbar() call returns (/plotline/, /caplines/, /barlinecols/)
> where 'plotline' describes the line part of the plot and the 'caplines'
> and 'barlinecols' describe the error bars and use the Path object.
>
> I just can't see how to change the values underlying the errorbars. I
> need to change the x and y values as well as the yerr values.
>
> Anybody have any idea how to do this? Or should I look at other
> approaches, such a simple line graph and a patch that draws error bars
> 'by hand'?

If you need to update everything, then you probably can't do much better 
than to simply clear the axes and call the errorbar method each time you 
need to update.  That is certainly the easy way--you might as well try 
it first.

Eric

>
> Thanks,
> Ross
>

I have been able to embed a matplotlib simple line graph into a wxpython 
application and then dynamically update the underlying line data.

However, I now want to do something similar with an errorbar plot.  I 
see that the errorbar() call returns (/plotline/, /caplines/, 
/barlinecols/) where 'plotline' describes the line part of the plot and 
the 'caplines' and 'barlinecols' describe the error bars and use the 
Path object.

I just can't see how to change the values underlying the errorbars.  I 
need to change the x and y values as well as the yerr values.

Anybody have any idea how to do this?  Or should I look at other 
approaches, such a simple line graph and a patch that draws error bars 
'by hand'?

Thanks,
Ross