Hi there -

I'm using the latest stable pylab/matplotlib (0.98.3) via OS X 10.5.4.  I am plotting a simple array of data, and I'm getting some strange behavior when I try to add a legend to the plot.
First, the plot without the legend:

f=figure(1)
title("Equilibrium Concentration vs. Equivalence Ratio")
line1 = plot(phi,xeq[1])
show()

This works fine.  However, when I try to add a legend, I get an error.  I add this:

f=figure(1)
title("Equilibrium Concentration vs. Equivalence Ratio")
line1 = plot(phi,xeq[1])
f.legend(line1,('CO2'),loc=(0.8,0.8))
show()

And it gives me an error because of the second argument to f.legend:

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)

/Users/charles/Documents/school/combustion/problem-2-52/adiabatic.py in <module>()
    111 title("Equilibrium Concentrations vs. Equivalence Ratio")
    112 line1=plot(phi,xeq[1])
--> 113 f.legend(line1,('CO2'),loc=(0.8,0.8))
    114 show()
    115

/Library/Python/2.5/site-packages/matplotlib-0.98.3-py2.5-macosx-10.3-i386.egg/matplotlib/figure.pyc in legend(self, handles, labels, *args, **kwargs)
    841         """
    842         handles = flatten(handles)
--> 843         l = Legend(self, handles, labels, *args, **kwargs)
    844         self.legends.append(l)
    845         return l

/Library/Python/2.5/site-packages/matplotlib-0.98.3-py2.5-macosx-10.3-i386.egg/matplotlib/legend.pyc in __init__(self, parent, handles, labels, loc, numpoints, prop, pad, markerscale, labelsep, handlelen, handletextsep, axespad, shadow)
    180         textleft = left+ self.handlelen+self.handletextsep
    181         self.texts = self._get_texts(labels, textleft, top)
--> 182         self.legendHandles = self._get_handles(handles, self.texts)
    183
    184         self._drawFrame = True

/Library/Python/2.5/site-packages/matplotlib-0.98.3-py2.5-macosx-10.3-i386.egg/matplotlib/legend.pyc in _get_handles(self, handles, texts)
    246         # centered marker proxy
    247
--> 248         for handle, label in safezip(handles, texts):
    249             if self.numpoints > 1:
    250                 xdata = np.linspace(left, left + self.handlelen, self.numpoints)

/Library/Python/2.5/site-packages/matplotlib-0.98.3-py2.5-macosx-10.3-i386.egg/matplotlib/cbook.pyc in safezip(*args)
    899     for i, arg in enumerate(args[1:]):
    900         if len(arg) != Nx:
--> 901             raise ValueError(_safezip_msg % (Nx, i+1, len(arg)))
    902     return zip(*args)
    903

ValueError: In safezip, len(args[0])=1 but len(args[1])=3
WARNING: Failure executing file: <adiabatic.py>

I don't understand why this doesn't work, because I should be able to give a label of arbitrary length.  It doesn't work when I replace single quotes with double quotes, either.  But I change the length to 1, like it wants:

f=figure(1)
title("Equilibrium Concentrations vs. Equivalence Ratio")
line1=plot(phi,xeq[1])
f.legend(line1,('C'),loc=(0.8,0.8))
show()

Which creates a plot, with a legend, but when I move the mouse over the plot, it has the "thinking" cursor (hourglass).   I can't close the window using the buttons in the upper left hand corner, I can't close it using close(1), and I can't close it using close('all').  I end up having to run 'killall Python' from a command line.

I can get the plot with the legend to work, albeit with only ONE character for the name, by running (from Python)

f=figure(1)
title("Equilibrium Concentrations vs. Equivalence Ratio")
line1=plot(phi,xeq[1])
f.legend(line1,('C'),loc=(0.8,0.8))

(without the show() command) in the script, then running show() when the script is done, and I don't get the "thinking" cursor.

Note: I have also used the function figlegend() with the exact same results/problems.

1. How can I give a legend name with a length of more than 1 character?  What am I doing wrong?
2. What is causing the behavior with the thinking cursor?


Also, ultimately I would like to make a plot with 30+ species, instead of just CO2.  Is there a way to do this other than doing the following?

line1 line2 line3 ........ = plot(phi,xeq[1],phi,xeq[2],phi,xeq[3],...........)
f.legend((line1,line2,...........),(name[0],name[1],name[2],................),loc=(0.8,0.8))

Thanks ahead of time for any suggestions or hints.



Charles