matplotlib-users Mailing List for matplotlib

Eric,
Exactly. Thanks for your post. I finally figured it out, and wanted to
post here for completeness in case no one followed up, but I'm glad
that you did. So yes, the following:
scatter(x, y, c=arange(len(x)), cmap=cm.spectral)
is exactly what I wanted... except that for my data I had:
Yvar1, Yvar2, Yvar3, ...
All data was plotted against Yvar1, and the first plot was Yvar1 vs.
Time. I wanted the colors for all the plots to be reflective of Time,
and consistently across the subplots, thus I had to define Time and
then use:
scatter(x, y, c=Time, cmap=cm.spectral)
However, I didn't try the arange function, I probably could've done
something like:
t=arange(Time)
scatter(x, y, c=t, cmap=cm.spectral)
Anyway, thanks again!
.john

John Washakie wrote:
> Trying again, a little more detail:
> 
> I am trying to use the color setting feature of SCATTER:
> 
> colors=cm.spectral(linespace(0,100,len(x))
> 
> then, plotting:
> 
> scatter(x,y,c=colors)
> 
> I get the error:
> TypeError: c must be a matplotlib color arg or a sequence of them
> 
> But I don't understand.
> 
>> x.shape
>> (600,)
>> colors.shape
>> (600,4)
> 
> so it appears to me that colors is indeed a sequence of intensities
> the same length as x? What is wrong then??
No, colors is a sequence of colors in this example, and I think that 
even if it did not give an error, it would not do what you want; but 
yes, I don't think this should give an error. And, on my system, a 
rough equivalent does not. What mpl version are you using?
Regardless, I think what you want is more like this:
scatter(x, y, c=arange(len(x)), cmap=cm.spectral)
Then the colors will be determined from a table lookup in the spectral 
colormap based on the floating point values in c, with the smallest 
value mapped to the first color and the largest value mapped to tha last.
Eric

Trying again, a little more detail:
I am trying to use the color setting feature of SCATTER:
colors=cm.spectral(linespace(0,100,len(x))
then, plotting:
scatter(x,y,c=colors)
I get the error:
TypeError: c must be a matplotlib color arg or a sequence of them
But I don't understand.
>x.shape
>(600,)
>colors.shape
>(600,4)
so it appears to me that colors is indeed a sequence of intensities
the same length as x? What is wrong then??
Thanks,
.john

Hello all,
I'm trying to create a plot in each element in my x,y array have a
slightly different color - using spectral for example.
My data is a time series, but I am not plotting the time series. I
want the older data to show up in a different color from the latest
data.
What I have so far is:
Y,y=rawD[:,7],rawD[:,i]
f=subplot(m,n,pltn)
colors=cm.spectral(linspace(0,1,len(Y)))
scatter(y,Y,2,cmap=colors)
pltn ,m, n are just iterators...
What am I doing wrong? I feel like I need to change somethig for the
cmap definition. I've tried iterating through Y and creating a scatter
plot for each pair, then assigning the color from colors[i], but that
crashes. Apparently you cannot scatter(x,y) where x,y are single
values.
Thanks!
.john

Tommy Grav <tg...@ma...> writes:
> I would now like to plot a vs e for all the obj objects in nlist.
> how do I do that? I tried
>
> plot(nlist[:].a,nlist[:].e,'ko')
You have a list of objects that have attributes named a and e; these
are not attributes of the list. Try
 plot([x.a for x in nlist], [x.e for x in nlist], 'ko')
-- 
Jouni K. Seppänen
http://www.iki.fi/jks

Hello Tommy,
I would like to do such convertings, too, but I think there is no such fast 
way in python. I'm using the 'for statement' to iterate over a list of 
objects and save their properties into a new list. 
best regards,
Matthias
On Friday 04 May 2007 17:54, Tommy Grav wrote:
> I have some code that simplified looks like this:
>
> class cKBO(object):
> 	def __init__(cls):
> 		cls.a = 0.
> 		cls.e = 0.
>
> lines = open("test.file","r").readlines()
>
> nlist = []
> for line in lines:
> 	obj = cKBO()
> 	(a,e) = line.split
> 	obj.a = float(a)
> 	obj.e = float(e)
> 	nlist.append(obj)
>
> I would now like to plot a vs e for all the obj objects in nlist.
> how do I do that? I tried
>
> plot(nlist[:].a,nlist[:].e,'ko')
> show()
>
> but that resulted in
> raceback (most recent call last):
> File "/Users/tgrav/Work/MyCode/Python/MOPS/ckbos.py", line 108, in ?
> plot(nlist[:].a,nlist[:].e,'ko')
> AttributeError: 'list' object has no attribute 'a'
>
> Which is understandable. But how do I most easily convert a list of
> class
> objects into two lists of object variables?
>
> Cheers
> Tommy
>
>
>
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Anyone able to "see" an animation using WXAgg 2.6 or otherwise on OS 
X 10.4 python 2.5 mpl 0.90.0
I can save figures and make a movie but nothing shows in the figure 
window until the animation is over.
even the example anim.py has the same behavior.
I have only been able to get it to work with tkAgg but that is seg 
faulting now.
**********************************************************************
Samuel M. Smith Ph.D.
2966 Fort Hill Road
Eagle Mountain, Utah 84005-4108
801-768-2768 voice
801-768-2769 fax
**********************************************************************
"The greatest source of failure and unhappiness in the world is
giving up what we want most for what we want at the moment"
**********************************************************************

Anyone using TkAgg on OSX 10.4 with MPL 0.90.0 and Python 2.5 
successfully?
**********************************************************************
Samuel M. Smith Ph.D.
2966 Fort Hill Road
Eagle Mountain, Utah 84005-4108
801-768-2768 voice
801-768-2769 fax
**********************************************************************
"The greatest source of failure and unhappiness in the world is
giving up what we want most for what we want at the moment"
**********************************************************************

I have been using WXAgg but I have had better success using TkAgg for 
animations.
So I tried TkAgg and get a segmentation fault. I haven't used it in a 
while so I don't know
when it stopped working. I have ipython 0.80 OS x 10.4.9 
scipysuperpack with MPL 0.90.0
anyone have any idea or used TkAgg lately?
backend TkAgg version 8.4
Python 2.5.1 (r251:54869, Apr 18 2007, 22:08:04)
Type "copyright", "credits" or "license" for more information.
IPython 0.8.0 -- An enhanced Interactive Python.
? -> Introduction to IPython's features.
%magic -> Information about IPython's 'magic' % functions.
help -> Python's own help system.
object? -> Details about 'object'. ?object also works, ?? prints more.
 Welcome to pylab, a matplotlib-based Python environment.
 For more information, type 'help(pylab)'.
In [1]: plot([1,2,5])
Segmentation fault
albook:samuel$
**********************************************************************
Samuel M. Smith Ph.D.
2966 Fort Hill Road
Eagle Mountain, Utah 84005-4108
801-768-2768 voice
801-768-2769 fax
**********************************************************************
"The greatest source of failure and unhappiness in the world is
giving up what we want most for what we want at the moment"
**********************************************************************