matplotlib-users Mailing List for matplotlib

Torsten,

You have found a bug, and I have not yet tracked down the cause and 
solution.  In the meantime, a workaround (or superior alternative--see 
below) is to use set_data(x, y) instead of set_xdata and set_ydata.  See 
the attached modification of your demo, which also shows an alternative 
way of making the mask.

> Every time when I pass a masked array to set_xdata() I get an error
> "MA.MA.MAError: Mask and data are not compatible".
> 
> See http://www-users.rwth-aachen.de/torsten.bronger/hall.py for the
> code that provokes this error.  The "plot" command works: It
> produces a plot with the desired gap (realised by the masked array).
> However, the first line.set_xdata(x_values) fails, although I even
> didn't change the x_values.

set_xdata and set_ydata call set_data, so it is actually more efficient 
to call set_data in the first place.  (This seems odd; one might expect 
the opposite, with set_data calling set_xdata and set_ydata.)

Eric

>>>>> "Jos=E9" =3D=3D Jos=E9 Matos <ja...@fc...> writes:

    Jos=E9> Hi all, I have been following this list for some time, as
    Jos=E9> well as using and spreading the news about matplotlib for
    Jos=E9> all people I know and use python. :-)

    Jos=E9>   I would like also to thank all the developers for all the
    Jos=E9> amazing work that has been done on matplotlib, it helps me a
    Jos=E9> lot in my work.

    Jos=E9>   Now the reason why I am writing to this list is to ask
    Jos=E9> what is the preferred policy for packaging matplotlib as an
    Jos=E9> rpm for FC4. Yesterday was accepted in Fedora Extras and so
    Jos=E9> it should take a few days to be available.

    Jos=E9>   The packager choose to package matplotlib (called
    Jos=E9> python-matplotlib) with both dateutils and pytz packaged
    Jos=E9> together while I use to package it as 3 separate packages.

Hi Jos=E9,

I have thought this over a bit more after talking with Fernando Perez,
a FC user, and wanted to add that in regards to the pytz and dateutils
packages, I think it is fine to package them separately.  My main
motivation for including them in the distro was to keep the list of
dependencies small, and because these packages did not have win32
friendly installers; neither issue should concern the FC4 packagers.

I would emphasize vis-a-vis these dependencies that the packager
should make sure the following examples run:

    peds-pc311:~/python/projects/matplotlib> ls examples/*date*
    examples/date_demo1.py  examples/date_demo_convert.py
    examples/date_demo2.py  examples/date_demo_rrule.py

and in general that the script examples/backend_driver.py, which runs
a suite of examples over several image backends, should not generate
errors.

As I mentioned in a previous response, I hope to factor some of these
dependencies into a separate, optional matplotlib-deps package to ease
the installation burden on the users while making the setup as clean
as possible for package maintainers.

Let me know if I can offer any more help, and thanks for your work
promoting matplotlib!

JDH=20

Jeff wrote:
>> I was having some difficulty filling between two vertical 
>> lines, I don't think I can use axvline() with fill()? 

On Thu, 23 Jun 2005, John Hunter apparently wrote: 
> It sounds like axvspan is what you want ... if all you 
> want is shading across the vertical extent over an xrange, 
> axvspan is the function for you,

Can this work directly with dates?
E.g., the following works but is non-intuitive:

import pylab
import datetime
d1 = datetime.date( 1995, 1, 1 )
d2 = datetime.date( 2004, 1, 1 )
delta = datetime.timedelta(days=365)
dates = pylab.drange(d1,d2,delta)
y = pylab.rand(len(dates))
pylab.axvspan(dates[2],dates[3])
pylab.plot_date(dates, y, 'r-')
pylab.show()

Thanks,
Alan Isaac

Christopher Kang wrote:

> Could someone please assist me in what I need to do or let me know of
> a different way to get matplotlib and gtk/gtkagg to work on my mac? 
> I'm running Tiger on the mac.

Do you really need GTK?

If not, you can use the installer at:

www.pythonmac.org/packages

It should work with TK, wx and Agg. I've heard someone is working on a 
Cocoa back-end which would be great, but it's not available now.

If you do need GTK, then you need to go the all-fink route: everything 
fink, including python itself, gtk, pygtk, etc.

Maybe whoever is maintaining the fink package can help out with your 
problems.

-Chris






-- 
Christopher Barker, Ph.D.
Oceanographer
                                     		
NOAA/OR&R/HAZMAT         (206) 526-6959   voice
7600 Sand Point Way NE   (206) 526-6329   fax
Seattle, WA  98115       (206) 526-6317   main reception

Chr...@no...

Hello, I'm not sure I have the most efficient method for changing my
plot settings.  I have an application I wrote with maplotlib that allows
a user to plot data and change different plot settings like color and
line width etc.  Initially when the program is created I create a
default axes with no data plotted.  The user then loads the data and
presses a plot button.

Once the data is plotted, each time the user changes the settings (for
example they change the line color from red to blue) I call
axes.clear(), then I call plot() again and this time I use the keywords
to change the settings to (change the line color to blue) and then I
call canvas.draw() to redraw the canvas.

axes.clear()
axes.plot(array,color=color, linestyle=pattern, linewidth=width,
marker='None')
canvas.draw()

Is this the best way to do this?

Thanks.

Jeff

>>>>> "Jeff" == Jeff Peery <jef...@se...> writes:

    Jeff> Hello, I'm using WXAgg for some simple plotting.  when I
    Jeff> change any of the settings in my figure and then call
    Jeff> canvas.draw() the figure that is redrawn is not the same
    Jeff> size as the old drawing until I resize my frame.  So
    Jeff> initially what I see is a new figure overlaying the old
    Jeff> figure.  However when I resize the frame the figure snaps to
    Jeff> the size it should be. How can I fix this so that the figure
    Jeff> draws correctly without having to resize my frame? Thanks.
 

example, example, example, please.  

It is really not possible for us to help you without an example that
exposes the problem.

JDH

Hello, I'm using WXAgg for some simple plotting.  when I change any of
the settings in my figure and then call canvas.draw() the figure that is
redrawn is not the same size as the old drawing until I resize my frame.
So initially what I see is a new figure overlaying the old figure.
However when I resize the frame the figure snaps to the size it should
be. How can I fix this so that the figure draws correctly without having
to resize my frame? Thanks.
 
  _____  

Jeffrey Thomas Peery
SeaMetrics, Inc.
Mechanical Engineer 
Jef...@Se...
253.872.0285 (fax)
253.872.0284 (phone)
  _____  

 

>>>>> "Torsten" == Torsten Bronger <br...@ph...> writes:

    Torsten> However, the datalim seems so implicitly include zero.
    Torsten> For example, if min(y_values) is 3, I still see the point
    Torsten> of origin.  How can I avoid this behaviour?

We're just doing what we're told here :-)

Your first plot call is

  y_values = total_number_values * [0.0]
  line, = plot(x_values, y_values)

So zero is *explicitly* included.  The datalim remember the history of
objects have have been added.  If you want them to ignore their
history, call 

ax.dataLim.update_numerix(x_values, y_values, True)

The third argument if True will cause the datalim to update it's
bounds ignoring history.   If False, it will update the bounds
including it's past history.

Note that in the original example you posted


for i in range(2*cycles):
    voltages = number_of_values * [i % 2 + 3]
    y_values[i * number_of_values : (i+1) * number_of_values] = \
                       voltages
    line.set_ydata(y_values)
    print min(y_values), max(y_values)
    ax.dataLim.update_numerix(x_values, y_values, True)


min(y_values) == 0

JDH

>>>>> "Brice" == Brice Thurin <B.P...@ci...> writes:

    Brice> Thank you for your help, I tried to do as you said and I
    Brice> got the following messages and then python quit: (I haven't
    Brice> planned to use PyGTK as I want to use WX.)  Many Thanks
    Brice> Brice

You have to set which GUI you want to use with the backend parameter
in the matplotlibrc configuration file.  Typically, people put a copy
of this in their HOME dir.  If you want to use WX, I suggest setting

backend : WXAgg

in your rc file.

You can obtain a default copy of the rc file at
http://matplotlib.sf.net/.matplotlibrc or in the matplotlib src
distribution.

JDH

>>>>> "David" =3D=3D David Abreu Rodriguez <dav...@ia...> writes:

    David> Hello, I am new in the list and new using matplotlib.

    David> I am using matplotlib version 0.74

    David> I want to write (in the title of a plot, for example) non
    David> ascii characters like =E1 or =E9, but I can't.  Other problem
    David> is writting mathtex expresions with normal text: I can't
    David> put 'title(r"test $\lambda$")' because I don't see the TeX
    David> character. I can write TeX characters only if I want to see
    David> the symbols.

matplotlib-0.74 introduced unicode support in the *Agg and PS backends
-- see examples/unicode_demo.py

Strings with "embedded mathtext" like (r"test $\lambda$") are
currently not supported but this is listed on the goals page -
http://matplotlib.sourceforge.net/goals.html.  You have to use
something like r"$\rm{test}\ \lambda$" currently.  This is discussed
in the mathtext class documentation at http://matplotlib.sourceforge.net/=
matplotlib.mathtext.html

matplotlib0.81 introduced mathtext support using TeX proper, see
http://matplotlib.sourceforge.net/screenshots.html#tex_demo and
http://matplotlib.sourceforge.net/matplotlib.texmanager.html

Hope this helps!
JDH

Hi David,

David Abreu Rodriguez wrote:
> Hello,
> 
> I am new in the list and new using matplotlib.
> 
> I am using matplotlib version 0.74
You might want to go with 0.82.
> 
> I want to write (in the title of a plot, for example) non ascii 
> characters like á or é, but I can't.
There were some problems when using e.g. date ticks (déc etc.), IRC they 
were fixed in 0.80.

For title and legend stuff I use decode along these lines:

title = self.selClientData[1].decode('iso-8859-1')

Hope this helps
Werner

> Other problem is writting mathtex expresions with normal text: I can't 
> put 'title(r"test $\lambda$")' because I don't see the TeX character. I 
> can write TeX characters only if I want to see the symbols.
> 
> thanks
> 
> 
> 
> -------------------------------------------------------
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> 

>>>>> "Jeff" == Jeff Peery <jef...@se...> writes:

    Jeff> I added the .matplotlibrc file and that definitely
    Jeff> helps. Thanks.  Regarding the symbols, I changed your file
    Jeff> to the match mine and I get symbols. Here's the change I
    Jeff> made:

    ...snip...

    Jeff> what is the difference here? Thank you very much for your
    Jeff> help.

If you are not passing a format string (eg 'r-') you need to
explicitly set the marker symbol.  For no marker at all, use the
string 'None'

  pylab.plot_date(dates, y, color ='r', marker='None', 
                  linestyle ='--',
                  linewidth = 1)

Using the string 'None' instead of the symbol None is a bit of a wart,
because None is currently interpreted to mean "use the rc default".

JDH

Hello,

I am new in the list and new using matplotlib.

I am using matplotlib version 0.74

I want to write (in the title of a plot, for example) non ascii=20
characters like =E1 or =E9, but I can't.
Other problem is writting mathtex expresions with normal text: I can't=20
put 'title(r"test $\lambda$")' because I don't see the TeX character. I=20
can write TeX characters only if I want to see the symbols.

thanks

Hello everyone and always, thank you for your tremendous help.  I was
just wondering, I need to get matplotlib to work on a mac but
unfortunately I've been running into some problems trying to get it to
work on a mac.  I tried by installing the unstable version from source
using fink and that has some parts of matplotlib working fine, but I
can't seem to import pylab.  Specifically, when matplotlib tries to
import pylab (from pylab import *), it eventually gets to
""from matplotlib._nc_backend_gdk import pixbuf_get_pixels_array"
ImportError: No module named _nc_backend_gdk.".  It seems like i don't
have a _nc_backend_gdk.so file that I need.

Could someone please assist me in what I need to do or let me know of
a different way to get matplotlib and gtk/gtkagg to work on my mac?=20
I'm running Tiger on the mac.

Thank you very much,
Chris

Thank you for your help, I tried to do as you said and I got the  
following messages and then python quit: (I haven't planned to use  
PyGTK as I want to use WX.)
Many Thanks
Brice

import pylab
/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site- 
packages/matplotlib/font_manager.py:456: UserWarning: Could not open  
font file /Library/Fonts/NISC18030.ttf
   warnings.warn("Could not open font file %s"%fpath)
/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site- 
packages/matplotlib/font_manager.py:456: UserWarning: Could not open  
font file /Library/Fonts/fonts.cache-1
   warnings.warn("Could not open font file %s"%fpath)
/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site- 
packages/matplotlib/font_manager.py:456: UserWarning: Could not open  
font file /System/Library/Fonts/LastResort.dfont
   warnings.warn("Could not open font file %s"%fpath)
/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site- 
packages/matplotlib/font_manager.py:456: UserWarning: Could not open  
font file /System/Library/Fonts/Keyboard.dfont
   warnings.warn("Could not open font file %s"%fpath)
No module named pygtk
PyGTK version 1.99.16 or greater is required to run the GTK Matplotlib  
backends

On 6 Jul 2005, at 15:51, John Hunter wrote:

>>>>>> "Brice" == Brice Thurin <B.P...@ci...> writes:
>     Brice> packages/matplotlib/font_manager.py", line 458, in
>     Brice> createFontDict prop = ttfFontProperty(font) File
>     Brice>  
> "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-
>     Brice> packages/matplotlib/font_manager.py", line 271, in
>     Brice> ttfFontProperty sfnt = font.get_sfnt() RuntimeError: No
>     Brice> SFNT name table
>
>
> Try editing matplotlib/font_manager.py on line 458 and replacing
>
>
>             prop = ttfFontProperty(font)
>
> with
>
>             try: prop = ttfFontProperty(font)
>             except: continue
>
> Let me know if this helps...
>
> JDH
>
>
Brice Thurin

Department of Optometry and Visual Science
City University, Northampton Square
London, EC1V 0HB, UK.
http://www.city.ac.uk/optometry/Luis/myresearch/Research/ 
scatteringproper.html
http://www.sharpeye.org/

Tel: +44 (0)20 7040 4157
Fax: +44(0)20 7040 8355
e-mail: B.P...@ci...

Hallöchen!

John Hunter <jdh...@ac...> writes:

> [...]
>
>
> OK, that helps.  The update of the data limits happens when you call
> plot and friends (technically plot calls ax.add_line which calls
> ax.update_datalim_numerix) .  If you manually set the xdata or ydata
> on the line object, you need to manually update the Axes datalim with
>
> ax = gca()
> for i in range(2*cycles):
>     voltages = number_of_values * [i % 2 + 3]
>     y_values[i * number_of_values : (i+1) * number_of_values] = \
>                        voltages
>     line.set_ydata(y_values)
>     ax.update_datalim_numerix(x_values, y_values)
>     ax.autoscale_view()
>
>     draw()
>     time.sleep(1)

However, the datalim seems so implicitly include zero.  For example,
if min(y_values) is 3, I still see the point of origin.  How can I
avoid this behaviour?

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus

Hallöchen!

Eric Firing <ef...@ha...> writes:

> [...]
>
> This looks to me like a place where you should try using masked arrays 
> instead of NaN.

Every time when I pass a masked array to set_xdata() I get an error
"MA.MA.MAError: Mask and data are not compatible".

See http://www-users.rwth-aachen.de/torsten.bronger/hall.py for the
code that provokes this error.  The "plot" command works: It
produces a plot with the desired gap (realised by the masked array).
However, the first line.set_xdata(x_values) fails, although I even
didn't change the x_values.

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus