matplotlib-users Mailing List for matplotlib

Hello,
I am new to matplotlib. My system administrator installed matplotlib 
(using gentoo's emerge command). There were no errors while installation, 
but wen i try to import pylab i get an error:

markacy@sun:~>python
Python 2.3.5 (#1, Apr 28 2005, 10:18:07)
[GCC 3.3.5-20050130 (Gentoo Linux 3.3.5.20050130-r1, ssp-3.3.5.20050130-1, 
pie- on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from pylab import *
Traceback (most recent call last):
   File "<stdin>", line 1, in ?
ImportError: No module named pylab
>>>

What is the problem??
Thanks,
Marek


Homo sum, humani nihil a me alienum puto.

I'm trying to define a custom colormap that is blue for -ve values, red 
for +ve values, and white at 0.  To this end, I've defined a new 
colormap with the following entries:

_redblue_data = {'red':  ((0.0, 0.0, 0.0),(0.5, 1.0, 1.0),(1.0, 1.0, 1.0)),
                'green': ((0.0, 0.0, 0.0),(0.5, 1.0, 1.0),(1.0, 0.0, 0.0)),
                'blue':  ((0.0, 1.0, 1.0),(0.5, 1.0, 1.0),(1.0, 0.0, 0.0))}

However, when I use this to plot a contourf of my data (setting the 
contour levels to be 0), the contour just below 0 is light blue, and the 
contour just above 0 is white.  In other words, instead of being 
symmetrical, the 'center' of the colormap is shifted towards the +ve.  
Is there any way to make the colormap symmetric around 0?

I'm using matplotlib-0.80.

Jordan

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

    Jeff> Thanks John, Well I don't know why I'm not using WXAgg, I'm
    Jeff> fairly new to this matplotlib stuff. I'm using wxpython,
    Jeff> will wxAgg work with this? Thanks.

Yes, the wx backend is something of a historical artifact.  Around
matplotlib-0.50, Perry Greenfield suggested using the antigrain
library as a core image renderer, and transfer this image into the
respective graphical user interfaces.  This idea came from Eric Jones
and Chaco.  This simplifies development enormously because we don't
have to deal with the idiosyncrasies of all the GUI drawing
libraries.  

The WXAgg backend in general will look a lot better and have more
features than the plain vanilla wx backend.  It is slower than we
would like it to be, because we are not using the most efficient
method to transfer the agg canvas to wx, and it doesn't have all the
save formats as wx does.  For example, I noticed your attached image
was jpg.  wxagg doesn't support jpeg, but uses png instead.  This is a
good thing.  You will be much happier with your wxagg png images than
you are with wx jpeg images I suspect.

JDH

Thanks John,

Well I don't know why I'm not using WXAgg, I'm fairly new to this
matplotlib stuff. I'm using wxpython, will wxAgg work with this? Thanks.

Jeff

-----Original Message-----
From: John Hunter [mailto:jdh...@ni...] 
Sent: Wednesday, May 25, 2005 11:43 AM
To: Jeff Peery
Cc: mat...@li...
Subject: Re: [Matplotlib-users] y label positioning

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

    Jeff> Hi, yes I attached an image and a piece of my script
    Jeff> (frame2.py). What do you think? Thanks.

I see.  This looks like a WX bug -- could you file a sourceforge bug
report and include your two files you attached?  


Is there a reason you are not using WXAgg?  This will probably fix
this problem for you and make nicer figures too..

import matplotlib
matplotlib.use('WXAgg')
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as
FigureCanvas
from matplotlib.backends.backend_wx import NavigationToolbar2Wx

JDH 

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

    Jeff> Hi, yes I attached an image and a piece of my script
    Jeff> (frame2.py). What do you think? Thanks.

I see.  This looks like a WX bug -- could you file a sourceforge bug
report and include your two files you attached?  


Is there a reason you are not using WXAgg?  This will probably fix
this problem for you and make nicer figures too..

import matplotlib
matplotlib.use('WXAgg')
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
from matplotlib.backends.backend_wx import NavigationToolbar2Wx

JDH 

Hi, yes I attached an image and a piece of my script (frame2.py). What
do you think? Thanks.



-----Original Message-----
From: John Hunter [mailto:jdh...@ni...] 
Sent: Wednesday, May 25, 2005 9:56 AM
To: Jeff Peery
Cc: mat...@li...
Subject: Re: [Matplotlib-users] y label positioning

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

    Jeff> Hello, I don't know if my last email was posted so I'll try
    Jeff> again. Is there a way to position a y axis label?  By
    Jeff> default it seems to be placed directly over the y-axis tick
    Jeff> marks and looks really bad. Thanks.

Could you post a script that replicates your problem, and possibly an
image.  Also the result of running your script with --verbose-helpful.

Thanks,
JDH

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

    Jeff> Hello, I don't know if my last email was posted so I'll try
    Jeff> again. Is there a way to position a y axis label?  By
    Jeff> default it seems to be placed directly over the y-axis tick
    Jeff> marks and looks really bad. Thanks.

Could you post a script that replicates your problem, and possibly an
image.  Also the result of running your script with --verbose-helpful.

Thanks,
JDH

Hello, I don't know if my last email was posted so I'll try again. Is
there a way to position a y axis label?  By default it seems to be
placed directly over the y-axis tick marks and looks really bad. Thanks.

Jeff

mencoder is part of mplayer.

http://www.mplayerhq.hu/homepage/design7/news.html

N.

Nils Wagner wrote:

> Hi all,
>
> I can't find mencoder on my system (SuSE Linux 9.1).
> Any pointer would be appreciated.
>
> Thanks in advance
>                                      Nils

On May 25, 2005, at 10:00 AM, Nils Wagner wrote:
>
> I can't find mencoder on my system (SuSE Linux 9.1).
> Any pointer would be appreciated.

The `mencoder' program comes with mplayer, the swiss army chainsaw of 
linux media players.  There are SuSE 9.1 RPMs at
	
	http://wiki.version6.net/RPM

I don't have access to a SuSE system right now, so I haven't been able 
to test 'em myself, but it's worth a try.

Ken

Hi all,

I can't find mencoder on my system (SuSE Linux 9.1).
Any pointer would be appreciated.

Thanks in advance
                                      Nils