Resizing Figure Box to Accommodate Expanding Legend

When moving the legend outside of the axis in Matplotlib, there is a challenge encountered where the legend may be cut off by the figure box. This issue occurs when the legend expands beyond the boundary of the plot area. Traditionally, adjusting the axis to accommodate the larger legend has been the recommended solution, but it may result in reducing the size of the data, making it more difficult to interpret.

Dynamic Resizing of Figure Box

To address this issue, the proposed solution is to dynamically resize the figure box to accommodate the expanding legend without altering the data size. This behavior is observed in R and LaTeX but was not immediately apparent in Python.

Code to Dynamically Resize Figure Box

The suggested code to accomplish this dynamic resizing is as follows:

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

In this code, lgd represents the legend object. By specifying bbox_extra_artists=(lgd,), we allow savefig to dynamically adjust the figure box to fit the legend.

Example with Complex Legend

Here is an example with a complex legend:

import matplotlib.pyplot as plt
import numpy as np

# Create figure and subplot
fig = plt.figure(1)
ax = fig.add_subplot(111)

# Plot data and create legend
ax.plot(x, np.sin(x), label='Sine')
ax.plot(x, np.cos(x), label='Cosine')
ax.plot(x, np.arctan(x), label='Inverse tan')
lgd = ax.legend(loc='upper center', bbox_to_anchor=(0.5,-0.1))

# Add arbitrary text for testing
text = ax.text(-0.2,1.05, "Aribitrary text", transform=ax.transAxes)

# Set title and grid
ax.set_title("Trigonometry")
ax.grid('on')

# Save figure with dynamic resizing
fig.savefig('samplefigure', bbox_extra_artists=(lgd,text), bbox_inches='tight')

This code generates a plot with a complex legend that extends beyond the axis area. The bbox_extra_artists parameter adjusts the figure box to accommodate the legend, resulting in the entire legend being displayed.

Note:

Since 2019, the code for dynamic resizing has become simplified. The following command is now sufficient:

plt.savefig('x.png', bbox_inches='tight')