In matplotlib, what's the difference between title() and suptitle()?

Question

I created 3 subplots using subplot(). Now I'd like to add titles for each subplot. Which one of title() and suptitle() shall I use?

In general, what is the difference between them? Thanks!

Answer 1

You can set the main figure title with fig.suptitle and subplot's titles with ax.set_title or by passing title to fig.add_subplot. For example:

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(-np.pi, np.pi, 0.01)

fig = plt.figure()
fig.suptitle('Main figure title')

ax1 = fig.add_subplot(311, title='Subplot 1 title')
ax1.plot(x, np.sin(x))

ax2 = fig.add_subplot(312)
ax2.set_title('Subplot 2 title')
ax2.plot(x, np.cos(x))

ax3 = fig.add_subplot(313)
ax3.set_title('Subplot 3 title')
ax3.plot(x, np.tan(x))

plt.show()

(You may need to manually tweak the font sizes to get the styling you want). I think subtitles need special placement and sizing of the text. For example, see Giving graphs a subtitle in matplotlib