Inserting a degree symbol into python plot

Question

This is a really simple problem but its escaping me. I'm just trying to insert a degree symbol into the titles and legends of my python plot. Code is below. Thanks.

from numpy import *
import numpy as np
import matplotlib.pyplot as plt

theta1 = linspace(0,60,610)
theta2 = linspace(0,45,460)
theta3 = linspace(45,90,460)

CTS = 1/cos(radians(theta1))
CTS0 = 1/cos(radians(60-theta2))
CTS45 = 1/cos(radians(105-theta3))

plt.plot(theta1,CTS,label=u'CTS Head at 0',linewidth=2)
plt.plot(theta2,CTS0,label='CTS Head at 60',linewidth=2)
plt.plot(theta3,CTS45,label='CTS Head at 105',linewidth=2)

plt.xlabel('Manufactured Ply Angle (degrees)')
plt.ylabel('Thickness')

plt.legend( loc='lower right', numpoints = 1 )
plt.ylim([0,2.5])

plt.grid(b=None, which='major', axis='both')
plt.grid(color='k', linestyle='--', linewidth=0.5)
plt.axhline(y=1.035, xmin=0, xmax=90,color='k', linestyle='-', linewidth=1)

plt.show()

Solution 1

Use LaTeX Style. For Example: $^\circ$ Text would produce °Text

See the matplotlib documentation for more information about printing (especially mathematical expression).

In your case the code has to be: plt.xlabel('Manufactured Ply Angle $^\circ$')

The TeX part of the expression must be enclosed by dollar signs "$".

Solution 2

Use LaTeX math. On my system the best visual appearance is achieved with

label = r'$45\degree$'

and it looks exactly like the default theta labels of a polar plot.

As others have pointed out kludges like

• label = r'$45^\circ$'
• label = '$45^o$'

etc. work too but the visual appearance is not so good. On my system these workarounds render a symbol that is slightly too small. YMMV, thus one may want to try what looks best on her system.

For example on a polar contour plot where radius is sine of zenith angle one may want to use

deg_labels = np.array([5, 10, 20, 30, 45, 60, 90])
ax.set_rgrids(np.sin(np.deg2rad(deg_labels)),     
              labels=(r"${:.0f}\degree$".format(_) for _ in deg_labels))

Solution 3

Use degree unicode symbol, especially if you don't need LaTeX for other symbols.

U+00B0: °

In python3, it's just: plt.xlabel("Manufactured Ply Angle (°)")

Solution 4

Similar to the answer given by dadaist, this also works for me to generate a degree symbol:

\N{degree sign}

so, in your example it would be

plt.xlabel('Manufactured Ply Angle (\N{degree sign})')

View more solutions

Comments

[Commoner]

The example of the depiction of degrees in the example of numpy array labels in a polar contour plot (the one at the very end) was very helpful. Much appreciation! =)

[Gordon Bai]

\degree looks better than ^\circ.