[Matplotlib-users] fill_between, legends, and "label" parameter

[Mike A. <mba...@wi...>]

Hi,

I have a piece of code that creates a plot without warning when using  
just fill(), but gives a warning when using fill_between() because  
that function doesn't seem to actually do register values passed to it  
by the "label" parameter.

The warning happens when I try to make a legend after using  
fill_between():
      /cms/sw/python/2.5/lib/python2.5/site-packages/ 
matplotlib-0.99.1.1_r0-py2.5-linux-x86_64.egg/matplotlib/axes.py:4014:  
UserWarning: No labeled objects found. Use label='...' kwarg on  
individual plots.
   warnings.warn("No labeled objects found. "

In essence this code works fine when I use fill() rather than  
fill_between():
--------------------
for column in sorted(yValues):
	ax.fill_between(xValues, yValues[column], label=column)

legend = plt.legend(bbox_to_anchor=(1.3, 1), shadow=True, fancybox=True)
--------------------

That is, the legend finds the labels when I use fill(), but not when I  
use fill_between().

Why is that?
Mike