matplotlib-users Mailing List for matplotlib

Hi,
In working on creating updating pcolor plots, I noticed that I can't 
create colorbars (which should be static) without first displaying an 
image. I have a fixed Normalize object and colormap, so I would think 
that the colorbar wouldn't actually need any information from the image 
itself.
Is there any to create a colorbar without first actually plotting an 
image? If not, is there any reason colorbar couldn't be modified to 
work using only a norm and a cmap?
Thanks,
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

Am I correct that you would like to add new kinds of plots to matplotlib 
that transform the raw data in some new way? Though transforms are 
involved, at the higher level you see this referred to as "projections" 
a lot in the mpl code.
There are a number of approaches you could take, all of which have 
different tradeoffs, rather than there being one "Right Way".
In matplotlib-0.91 (and earlier) there is an underlying framework for 
doing transformations (in _transforms.cpp). This framework, while its 
does it job well, is kind of obscure and difficult to extend with new 
kinds of transformations. But it's certainly doable, and you can look 
at the code for polar plots (in axes.py) for an example.
As a result, the current SVN trunk has been heavily refactored to make 
adding new kinds of projections easier. I'm biased because I did a lot 
of that work, so I wouldn't want to claim that it is significantly 
easier until someone else comes along and uses the new framework to 
build something new. (I think the soil texture triangle plot you 
suggest seems like it would be a reasonably good fit, though). If you 
decide to take this approach, there is documentation for making new 
projections here:
http://matplotlib.svn.sourceforge.net/viewvc/*checkout*/matplotlib/trunk/matplotlib/doc/devel/add_new_projection.rst
Again, that documentation has largely gone unused by anyone but myself, 
so please let me know where it needs improvement. Of course, the 
downside is that it may be a number of months until the SVN trunk is 
released as a stable version.
Alternatively to all of the above, you could take the approach of 
"basemap" (a toolkit extension to matplotlib). It (essentially) does 
all of the transformation of the data into a given projection internally 
and then passes that along as a regular Cartesian 2D plot to 
matplotlib. That approach does work well, and has shown to be rather 
robust to internal changes in mpl, since it primarily uses the "public" 
(and more stable) APIs.
Hope that helps. Please ask if you have any more questions as you go.
Mike
Chloe Lewis wrote:
> I stick to releases, so, 0.91.2; although if the transforms are about 
> to change a lot, maybe I'll put off the 'right way'.
>
> The first thing I'm writing is an easy version of the 'soil texture 
> triangle' -- plotting x+y+z=100, but on an equilateral triangle:
>
> http://www.uwsp.edu/geo/faculty/ritter/glossary/s_u/soil_texture_triangle.html 
>
>
> Scatters and patches on this are handy.
>
> There's another handful of triangular, sort-of-rigorous 3-variable 
> graphs commonly used by ecosystem scientists, which I'd like to extend 
> to.
>
> &C
>
>
> On Mar 7, 2008, at 7 Mar, 10:30 AM, Michael Droettboom wrote:
>
>> Can you be a bit more specific about what you're trying to do? (Are 
>> you working with the latest SVN trunk, or the latest release 0.91.x? 
>> The two are considerably different wrt to the transforms framework(s)).
>>
>> Cheers,
>> Mike
>>
>> Chloe Lewis wrote:
>>> Any current transforms examples? The transforms docs suggest 
>>> looking in /units for transforms examples; the current matplotlib 
>>> examples has /units without transforms. (I want something a bit 
>>> more detailed than the offset.)
>>>
>>> If the transforms are currently too much in flux, I'll do something 
>>> one-off, but I'd like to do it the Right Way if I can.
>>>
>>> &C
>>>
>>>
>>>
>>>
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>>>
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>>
>> -- 
>> Michael Droettboom
>> Science Software Branch
>> Operations and Engineering Division
>> Space Telescope Science Institute
>> Operated by AURA for NASA
>>
>
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Can you be a bit more specific about what you're trying to do? (Are you 
working with the latest SVN trunk, or the latest release 0.91.x? The 
two are considerably different wrt to the transforms framework(s)).
Cheers,
Mike
Chloe Lewis wrote:
> Any current transforms examples? The transforms docs suggest looking 
> in /units for transforms examples; the current matplotlib examples 
> has /units without transforms. (I want something a bit more detailed 
> than the offset.)
>
> If the transforms are currently too much in flux, I'll do something 
> one-off, but I'd like to do it the Right Way if I can.
>
> &C
>
>
>
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Microsoft
> Defy all challenges. Microsoft(R) Visual Studio 2008.
> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> 
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Any current transforms examples? The transforms docs suggest looking 
in /units for transforms examples; the current matplotlib examples 
has /units without transforms. (I want something a bit more detailed 
than the offset.)
If the transforms are currently too much in flux, I'll do something 
one-off, but I'd like to do it the Right Way if I can.
&C

Hello, I just upgraded to the most recent version of matplotlib. I'm trying to freeze my wx app with py2exe. I'm getting this error:
 
 error: cannot copy ...mpl-data/matplotlib.nib. doesn't exist or is not a regular file
 
 how do I correct this error? thanks!
 
 Jeff
 
 
---------------------------------
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On Fri, Mar 7, 2008 at 2:48 AM, Troels Kofoed Jacobsen
<tkj...@gm...> wrote:
> Hi all
>
> Can i make something transparent?
>
> E.g the markerfacecolor?
Set the alpha to a value less than one, eg
ax.plot(something, mfc='green', alpha=0.5)
JDH

Hi All,
Apologies if I'm missing anything obvious...
How do I plot lines point-by-point as opposed to by passing arrays?
I'm guessing something like:
plot([x],[y])
...but that feels a bit weird to me.
In any case, using that, I don't know how to plot more than one line at 
a time, so thought I'd ask here...
Hope you can help!
cheers,
Chris
-- 
Simplistix - Content Management, Zope & Python Consulting
 - http://www.simplistix.co.uk

Hi all
Can i make something transparent?
E.g the markerfacecolor?
--
Med Venlig Hilsen /Best Regards
Troels Kofoed Jacobsen