问题
In matplotlib you can make the text of an axis label bold by
plt.xlabel('foo',fontweight='bold')
You can also use LaTeX with the right backend
plt.xlabel(r'$\phi$')
When you combine them however, the math text is not bold anymore
plt.xlabel(r'$\phi$',fontweight='bold')
Nor do the following LaTeX commands seem to have any effect
plt.xlabel(r'$\bf \phi$')
plt.xlabel(r'$\mathbf{\phi}$')
How can I make a bold $\phi$ in my axis label?
回答1:
Unfortunately you can't bold symbols using the bold font, see this question on tex.stackexchange.
As the answer suggests, you could use \boldsymbol to bold phi:
r'$\boldsymbol{\phi}$'
You'll need to load amsmath into the TeX preamble:
matplotlib.rc('text', usetex=True)
matplotlib.rcParams['text.latex.preamble']=[r"\usepackage{amsmath}"]
回答2:
If you intend to have consistently bolded fonts throughout the plot, the best way may be to enable latex and add \boldmath to your preamble:
# Optionally set font to Computer Modern to avoid common missing font errors
matplotlib.rc('font', family='serif', serif='cm10')
matplotlib.rc('text', usetex=True)
matplotlib.rcParams['text.latex.preamble'] = [r'\boldmath']
Then your axis or figure labels can have any mathematical latex expression and still be bold:
plt.xlabel(r'$\frac{\phi + x}{2}$')
However, for portions of labels that are not mathematical, you'll need to explicitly set them as bold:
plt.ylabel(r'\textbf{Counts of} $\lambda$'}
回答3:
As this answer Latex on python: \alpha and \beta don't work? points out. You may have a problem with \b so \boldsymbol may not work as anticipated. In that case you may use something like: '$ \\\boldsymbol{\\\beta} $' in your python code. Provided you use the preamble plt.rcParams['text.latex.preamble']=[r"\usepackage{amsmath}"]
来源：https://stackoverflow.com/questions/14324477/bold-font-weight-for-latex-axes-label-in-matplotlib