[Matplotlib-users] MatplotLib Figure Legends

[Jim B. <jb...@se...>]

Hi John,

  Today i finally got around to trying a suggestion 
that you made on May 22...on how to put a legend on a Figure
(outside of the axis). So i hacked up the example 
legendDemo.py to experiment with:

# Haked up legendDemp.py

# Thanks to Charles Twardy for this example
from matplotlib.matlab import *

a = arange(0,3,.02)
b = arange(0,3,.02)
c=exp(a)
d=c.tolist()
d.reverse()
d = array(d)

ax = subplot(111)
lines = plot(a,c,'k--',a,d,'k:',a,c+d,'k')
#legend(('Model length', 'Data length', 'Total message length'), 'upper 
left')
fig = gcf()

line1 = lines[0]
line2 = lines[1]
line3 = lines[2]

fig.legend((line1, line2, line3),
           ('Model length', 'Data length', 'Total message length'),
           'upper left')

ax.set_ylim([-1,20])
ax.grid(0)
xlabel('Model complexity --->')
ylabel('Message length --->')
title('Minimum Message Length')
set(gca(), 'yticklabels', [])
set(gca(), 'xticklabels', [])

savefig('legend_demo_small', dpi=60)
savefig('legend_demo_large', dpi=120)

show()

# End of: Haked up legendDemp.py

I then go the following error:

clavius:/home/jbenson/python>python legendDemo.py
Traceback (most recent call last):
  File "legendDemo.py", line 22, in ?
    'upper left')
  File "/usr/local/lib/python2.3/site-packages/matplotlib/figure.py", line 
179, in legend
    l = Legend(handles, labels, loc)
TypeError: __init__() takes exactly 5 arguments (4 given)
clavius:/home/jbenson/python>

Should that line 179 in figure.py be:

        l = Legend(self, handles, labels, loc)  # -added ->self<- ?

Just for fun, i tried that change and re-ran:

clavius:/home/jbenson/python>python legendDemo.py
Traceback (most recent call last):
  File "legendDemo.py", line 22, in ?
    'upper left')
  File "/usr/local/lib/python2.3/site-packages/matplotlib/figure.py", line 
179, in legend
    l = Legend(self, handles, labels, loc)
  File "/usr/local/lib/python2.3/site-packages/matplotlib/legend.py", line 
107, in __init__
    self._texts = self._get_texts(labels, textleft, upper)
  File "/usr/local/lib/python2.3/site-packages/matplotlib/legend.py", line 
215, in _get_texts
    HEIGHT = self._approx_text_height()
  File "/usr/local/lib/python2.3/site-packages/matplotlib/legend.py", line 
126, in _approx_text_height
    return 
self.FONTSIZE/72.0*self.figure.dpi.get()/self.parent.bbox.height()
AttributeError: 'NoneType' object has no attribute 'dpi'
clavius:/home/jbenson/python>

...so those errors look worse.

(i'm using matplotlib-0.54.2)

Any more hints?

Thanks,

Jim