How to Position the Legend Outside the Plot in Matplotlib

To position the legend outside the plot in Matplotlib, you can use the bbox_to_anchor parameter of the legend function. This parameter allows you to specify the coordinates of the legend relative to the figure, rather than the axes. Here’s how you can do it:

Method 1: Using the bbox_to_anchor parameter

1. Create a plot using Matplotlib.
2. Add a legend to the plot using the legend function.
3. Specify the bbox_to_anchor parameter with the coordinates where you want the legend to be positioned. The coordinates are specified as a tuple of four values: (x, y, width, height). The x and y values specify the lower-left corner of the legend, and the width and height values specify the size of the legend. By default, the coordinates are in the range [0, 1], where (0, 0) is the lower-left corner of the plot and (1, 1) is the upper-right corner.
4. Call the plot function to plot your data.
5. Call the show function to display the plot.

Here’s an example:

import matplotlib.pyplot as plt

# Create a plot
plt.plot([1, 2, 3], [4, 5, 6], label='Line 1')
plt.plot([1, 2, 3], [6, 5, 4], label='Line 2')

# Add a legend outside the plot
plt.legend(bbox_to_anchor=(1.01, 1), loc='upper left')

# Display the plot
plt.show()

In this example, the legend is positioned slightly to the right of the plot and aligned with the upper left corner of the plot.

Method 2: Using the loc parameter

Another way to position the legend outside the plot is by using the loc parameter of the legend function. This parameter allows you to specify the location of the legend within the plot. To position the legend outside the plot, you can set the loc parameter to a value that is not within the plot area, such as 'upper left' or 'upper right'.

Here’s an example:

import matplotlib.pyplot as plt

# Create a plot
plt.plot([1, 2, 3], [4, 5, 6], label='Line 1')
plt.plot([1, 2, 3], [6, 5, 4], label='Line 2')

# Add a legend outside the plot
plt.legend(loc='upper left')

# Display the plot
plt.show()

In this example, the legend is positioned outside the plot in the upper left corner.

Additional Tips

– You can adjust the position of the legend by changing the values of the bbox_to_anchor parameter or the loc parameter. Experiment with different values to achieve the desired position.
– If you want to control the size of the legend, you can use the prop parameter of the legend function to set the font size. For example, plt.legend(prop={'size': 10}) sets the font size of the legend to 10.
– If you have multiple legends in your plot, you can specify the bbox_to_anchor parameter or the loc parameter for each legend separately to position them independently.