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matplotlib python

How to set a single, main title above all the subplots with Pyplot?

326

I am using pyplot. I have 4 subplots. How to set a single, main title above all the subplots? title() sets it above the last subplot.

    415

    Use pyplot.suptitle or Figure.suptitle:

    import matplotlib.pyplot as plt
    import numpy as np
    
    fig=plt.figure()
    data=np.arange(900).reshape((30,30))
    for i in range(1,5):
        ax=fig.add_subplot(2,2,i)        
        ax.imshow(data)
    
    fig.suptitle('Main title') # or plt.suptitle('Main title')
    plt.show()
    

    enter image description here

    2

    • 1

      Works with suptitle. Still, I saw your “shameless hack!” 🙂

      – Jakub M.

      Aug 15, 2011 at 15:08

    • 12

      Note, it is plt.suptitle() and not plt.subtitle(). I did not realize this in the beginning and got a nasty error! 😀

      – Dataman

      May 10, 2016 at 15:40

    194

    A few points I find useful when applying this to my own plots:

    • I prefer the consistency of using fig.suptitle(title) rather than plt.suptitle(title)
    • When using fig.tight_layout() the title must be shifted with fig.subplots_adjust(top=0.88)
    • See answer below about fontsizes

    Example code taken from subplots demo in matplotlib docs and adjusted with a master title.

    A nice 4x4 plot

    import matplotlib.pyplot as plt
    import numpy as np
    
    # Simple data to display in various forms
    x = np.linspace(0, 2 * np.pi, 400)
    y = np.sin(x ** 2)
    
    fig, axarr = plt.subplots(2, 2)
    fig.suptitle("This Main Title is Nicely Formatted", fontsize=16)
    
    axarr[0, 0].plot(x, y)
    axarr[0, 0].set_title('Axis [0,0] Subtitle')
    axarr[0, 1].scatter(x, y)
    axarr[0, 1].set_title('Axis [0,1] Subtitle')
    axarr[1, 0].plot(x, y ** 2)
    axarr[1, 0].set_title('Axis [1,0] Subtitle')
    axarr[1, 1].scatter(x, y ** 2)
    axarr[1, 1].set_title('Axis [1,1] Subtitle')
    
    # # Fine-tune figure; hide x ticks for top plots and y ticks for right plots
    plt.setp([a.get_xticklabels() for a in axarr[0, :]], visible=False)
    plt.setp([a.get_yticklabels() for a in axarr[:, 1]], visible=False)
    
    # Tight layout often produces nice results
    # but requires the title to be spaced accordingly
    fig.tight_layout()
    fig.subplots_adjust(top=0.88)
    
    plt.show()
    

    1

    • 3

      Simply adding figure.suptitle() is not enough since titles of subplots will mix with suptitile, fig.subplots_adjust(top=0.88) is good.

      Mar 22, 2019 at 2:28

    46

    If your subplots also have titles, you may need to adjust the main title size:

    plt.suptitle("Main Title", size=16)
    

    1

    • 10

      In python 2.7 it is fontsize instead of size. plt.suptitle("Main Title", fontsize=16)

      – Temak

      Feb 11, 2016 at 17:59