Typing Greek letters etc. in plots

Question

I need to type Greek letters and the Angstrom symbol in labels of axes in a plot. So for example

fig.gca().set_xlabel("$wavelength\, (Angstrom)$")
fig.gca().set_ylabel("$lambda$")

except that I actually want "Angstrom" and "lambda" replaced by actual symbols. How should I do this? Thanks!

tacaswell · Answer 1 · 2017-03-02T16:45:08.030

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You need to make the strings raw and use latex:

fig.gca().set_ylabel(r'$\lambda$')

As of matplotlib 2.0 the default font supports most western alphabets and can simple do

ax.set_xlabel('λ')

with unicode.

edited Mar 02 '17 at 16:45

answered Nov 12 '12 at 04:55

tacaswell

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BandGap · Accepted Answer · 2013-01-05T22:44:16.017

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Not only can you add raw strings to matplotlib but you can also specify the font in matplotlibrc or locally with:

from matplotlib import rc

rc('font', **{'family':'serif','serif':['Palatino']})
rc('text', usetex=True)

This would change your serif latex font. You can also specify the sans-serif Helvetica like so

rc('font',**{'family':'sans-serif','sans-serif':['Helvetica']})

Other options are cursive and monospace with their respective font names. Your label would then be

fig.gca().set_xlabel(r'wavelength $5000 \AA$')

If the font doesn't supply an Angstrom symbol you can try using \mathring{A}

edited Jan 05 '13 at 22:44

answered Jan 03 '13 at 21:49

BandGap

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The Angstrom is not satisfactory with this option, because it appear italic. The $\text{\AA}$ which works in latex does seem to work here. Also there should an option which preserved the font used for these characters. How to do that? – leandro Sep 14 '16 at 15:01
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You can use the letter Å instead of a dedicated Ångström symbol (Å), since very few fonts contain the latter, and most ot them use identical glyphs for both, anyway. https://en.wikipedia.org/wiki/%C3%85#Symbol_for_.C3.A5ngstr.C3.B6m – Håken Lid Dec 04 '16 at 10:20

score 18 · Answer 3 · answered Oct 14 '13 at 00:35

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If you want tho have a normal string infront of the greek letter make sure that you have the right order:

plt.ylabel(r'Microstrain [$\mu \epsilon$]')

answered Oct 14 '13 at 00:35

Frelm

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score 13 · Answer 4 · edited May 28 '16 at 20:46

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Python 3.x: small greek letters are coded from 945 to 969 so,alpha is chr(945), omega is chr(969) so just type

print(chr(945))

the list of small greek letters in a list:

greek_letterz=[chr(code) for code in range(945,970)]

print(greek_letterz)

And now, alpha is greek_letterz[0], beta is greek_letterz[1], a.s.o

edited May 28 '16 at 20:46

Dmitriy Simushev

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answered Sep 12 '15 at 07:55

Arpad Kosa

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Håken Lid · Answer 5 · 2021-10-26T09:15:28.367

Why not just use the literal characters?

fig.gca().set_xlabel("wavelength, (Å)")
fig.gca().set_ylabel("λ")

You might have to add this to the file if you are using python 2:

# -*- coding: utf-8 -*-
from __future__ import unicode_literals  # or use u"unicode strings"

It might be easier to define constants for characters that are not easy to type on your keyboard.

ANGSTROM, LAMDBA = "Åλ"

Then you can reuse them elsewhere.

fig.gca().set_xlabel("wavelength, (%s)" % ANGSTROM)
fig.gca().set_ylabel(LAMBDA)

score 1 · Answer 6 · answered Aug 25 '21 at 08:56

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You can just use unicode characters in python. See the following link Unicode characters for engineers in Python .

answered Aug 25 '21 at 08:56

uoay

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score 0 · Answer 7 · answered Mar 19 '22 at 19:57

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print('Omega: \u03A9') # Ω
print('Lamda: \u03BB') # λ

Visit the Website for more symbols More Symbols

answered Mar 19 '22 at 19:57

HackerGprat

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Typing Greek letters etc. in plots

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