The difference between \dfrac and \frac

In this example, the differences between the \dfrac and \frac TeX macros are illustrated; in particular, the difference between display style and text style fractions when using Mathtex.

Added in version 2.1.

Note

To use \dfrac with the LaTeX engine (text.usetex : True), you need to import the amsmath package with the text.latex.preamble rc, which is an unsupported feature; therefore, it is probably a better idea to just use the \displaystyle option before the \frac macro to get this behavior with the LaTeX engine.

import matplotlib.pyplot as plt

fig = plt.figure(figsize=(5.25, 0.75))
fig.text(0.5, 0.3, r'\dfrac: $\dfrac{a}{b}$',
         horizontalalignment='center', verticalalignment='center')
fig.text(0.5, 0.7, r'\frac: $\frac{a}{b}$',
         horizontalalignment='center', verticalalignment='center')
plt.show()