My matplotlib.pyplot legend is being cut off

I'm attempting to create a plot with a legend to the side of it using matplotlib. I can see that the plot is being created, but the image bounds do not allow the entire legend to be displayed.

lines = []
ax = plt.subplot(111)
for filename in args:
    lines.append(plt.plot(y_axis, x_axis, colors[colorcycle], linestyle='steps-pre', label=filename))
ax.legend(bbox_to_anchor=(1.05, 1), loc=2, borderaxespad=0.)

This produces: enter image description here

Solution 1:

Eventhough that it is late, I want to refer to a nice recently introduced alternative:

New matplotlib feature: The tight bounding box

If you are interested in the output file of plt.savefig: in this case the flag bbox_inches='tight' is your friend!

import matplotlib.pyplot as plt

fig = plt.figure(1)
plt.plot([1, 2, 3], [1, 0, 1], label='A')
plt.plot([1, 2, 3], [1, 2, 2], label='B')
plt.legend(loc='center left', bbox_to_anchor=(1, 0))

fig.savefig('samplefigure', bbox_inches='tight')

Output file: samplefigure.png

I want to refer also to a more detailed answer: Moving matplotlib legend outside of the axis makes it cutoff by the figure box

Advantages

There is no need to adjust the actual data/picture.
It is compatible with plt.subplots as-well where as the others are not!
It applies at least to the mostly used output files, e.g. png, pdf.

Solution 2:

As pointed by Adam, you need to make space on the side of your graph. If you want to fine tune the needed space, you may want to look at the add_axes method of matplotlib.pyplot.artist.

Below is a rapid example:

import matplotlib.pyplot as plt
import numpy as np

# some data
x = np.arange(0, 10, 0.1)
y1 = np.sin(x)
y2 = np.cos(x)

# plot of the data
fig = plt.figure()
ax = fig.add_axes([0.1, 0.1, 0.6, 0.75])
ax.plot(x, y1,'-k', lw=2, label='black sin(x)')
ax.plot(x, y2,'-r', lw=2, label='red cos(x)')
ax.set_xlabel('x', size=22)
ax.set_ylabel('y', size=22)
ax.legend(bbox_to_anchor=(1.05, 1), loc=2, borderaxespad=0.)

plt.show()

and the resulting image:

Solution 3:

Just use plt.tight_layout()

import matplotlib.pyplot as plt
    
fig = plt.figure(1)
plt.plot([1, 2, 3], [1, 0, 1], label='A')
plt.plot([1, 2, 3], [1, 2, 2], label='B')
plt.legend(loc='center left', bbox_to_anchor=(1, 0))

plt.tight_layout()

This is probably introduced in the newer matplotlib version and neatly does the job.

Solution 4:

Here is another way of making space (shrinking an axis):

# get the current axis
ax = plt.gca()
# Shink current axis by 20%
box = ax.get_position()
ax.set_position([box.x0, box.y0, box.width * 0.8, box.height])

where 0.8 scales the width of the axis by 20%. On my win7 64 machine, using a factor greater than 1 will make room for the legend if it's outside the plot.

This code was referenced from: How to put the legend out of the plot