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!
Answers:
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.
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}
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 [$mu epsilon$]')
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
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)
You can just use unicode characters in python. See the following link Unicode characters for engineers in Python
.
print('Omega: u03A9') # Ω
print('Lamda: u03BB') # λ
Visit the Website for more symbols
More Symbols
This should display the Angstrom (nonitalicized).
ax.set_xlabel("$mathrm{AA}$",labelpad=2, fontsize=10,fontweight='bold')
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!
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.
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}
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 [$mu epsilon$]')
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
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)
You can just use unicode characters in python. See the following link Unicode characters for engineers in Python
.
print('Omega: u03A9') # Ω
print('Lamda: u03BB') # λ
Visit the Website for more symbols
More Symbols
This should display the Angstrom (nonitalicized).
ax.set_xlabel("$mathrm{AA}$",labelpad=2, fontsize=10,fontweight='bold')