How to include the squared symbol in a graph label

Question

I want to plot the value of R2 in my graph, but I don't know how to write the "2" as an exponent. How can I do that? Below you can find the code and the plot.

plt.figure()
plt.plot((y_train1),(y_train_pred),'.', color='darkviolet', alpha=1, marker='o', markersize = 2, markeredgecolor = 'black', markeredgewidth = 0.1)
plt.plot((np.array((-0.1,7))),(np.array((-0.1,7))),'-', color='magenta')
plt.xlabel('True')
plt.ylabel('Predicted')
plt.title('Train')
plt.text(5, 1, "R2 score EO: {:0.2f}".format(r2_train_EO), style='italic')

score 3 · Accepted Answer · answered Feb 09 '20 at 16:02

While the answer referencing latex would work - having to install latex for such a small change is a lot of hassle. This could be achieved by just using the unicode squared symbol in the label string:

plt.text(5, 1, u"R\u00b2 score EO: {:0.2f}".format(r2_train_EO), style='italic')

Stefan · Answer 2 · 2020-02-09T15:53:16.027

2

You should configure pyplot to use Latex:

from matplotlib import rc
rc('text', usetex=True)

Then write R^2 in your label.

Edit: the above is recommended if you also want to control fonts. If that is not needed, just write '$R^2$' in your text - this is also Latex.

edited Feb 09 '20 at 15:53

answered Feb 09 '20 at 15:47

Stefan

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it gives me this error: RuntimeError: Failed to process string with tex because latex could not be found. How can I fix it? Maybe I have to download some library? – Gabriele Valvo Feb 09 '20 at 15:54
Which operating system? – Stefan Feb 09 '20 at 15:58
The operating system is Zorin – Gabriele Valvo Feb 09 '20 at 15:59
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And, please try the second option, without loading the rc library - the problem could be missing fonts – Stefan Feb 09 '20 at 16:00
I think you should follow the advice in https://stackoverflow.com/questions/11354149/python-unable-to-render-tex-in-matplotlib – Stefan Feb 09 '20 at 16:03
Ok, it doesn't work with the last advice that you give me. – Gabriele Valvo Feb 09 '20 at 16:04

score 0 · Answer 3 · answered May 23 '23 at 10:44

0

you could also try:

plt.text(5, 1, f"$R^2$ score EO: {r2_train_EO:0.2f}", style='italic')

answered May 23 '23 at 10:44

Pietro

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Can you explain why and provide some docs? – Matteus Barbosa May 23 '23 at 15:52

How to include the squared symbol in a graph label

3 Answers3