# [Tutor] Problem with Plot Legend

Stephen P. Molnar s.molnar at sbcglobal.net
Tue Jun 13 14:55:22 EDT 2017

```I am using Python3.6 in the Spyder3IDE and have a problem with the
legend for a plot.

I have attached the pg file.

The code (in part) is:
import numpy as np
from mpl_toolkits.axes_grid1 import host_subplot
import mpl_toolkits.axisartist as AA
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches

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(the portion of the code for Figure q1 has no problems)

def two_scales(ax1, time, data1, data2, c1, c2)

ax2 = ax1.twinx()

ax1.plot(time, data1, 'r')
ax1.set_xlabel("Distance (\$\AA\$)")
ax1.set_ylabel('Atom Charge',color='r')

ax2.plot(time, data2, 'b')
ax2.set_ylabel('Orbital Energy',color='b')
return ax1, ax2

t = data[:,0]
s1 = data[:,3]
s2 = data[:,5]

# Create axes
fig, ax = plt.subplots()
ax1, ax2 = two_scales(ax, t, s1, s2, 'r', 'b')

# Change color of each axis
def color_y_axis(ax, color):
for t in ax.get_yticklabels():
t.set_color(color)
return None
color_y_axis(ax1, 'r')
color_y_axis(ax2, 'b')

plt.title('Molecular Transforms')

patch_red = mpatches.Patch(color='red',label='Atom Charge')
patch_blue = mpatches.Patch(color='blue',label='Orbital Energy')
plt.legend(handles = [patch_red,patch_blue])

plt.draw()
plt.show()

name_plt = name+'-fig2.png'
fig.savefig(name_plt,bbox_inches='tight')

The problem is that the legend is where I want it in the figure and
contains what I want with one exception:

The colored lines are too thick, the same width as the text.

I've look in the literature and Googled for the solution, but I'm
beginning to think that I don't know just what the question that I

A pointer towards thech solution to this problem will be much appreciated.