Upright mu in plot label: retaining original tick fonts

Question

I have a problem which I thought would be more occurring. However, after scouring the internet for some time now I have not been able to find the solution to my problem. So

Answer 1

I am also struggling with such a problem, i.e. getting the tick labels and axes labels to be consistent when text.usetex = True. The solution that I have managed to find it not ideal, but it works for the moment.

What you have to do is set the font family to "sans-serif" and also add a latex package that uses sans-serif math fonts (sfmath -- make sure it is in your tex path!)

import matplotlib
import matplotlib.pyplot as plt

matplotlib.rc('text', usetex = True)
matplotlib.rc('font', **{'family':"sans-serif"})
params = {'text.latex.preamble': [r'\usepackage{siunitx}', 
    r'\usepackage{sfmath}', r'\sisetup{detect-family = true}',
    r'\usepackage{amsmath}']}   
plt.rcParams.update(params)   

fig = plt.figure(figsize = (4,4))
ax = fig.add_subplot(1,1,1)
ax.set_xlabel('$\si{\um} detection$')
ax.set_ylabel(r"$\mu \boldsymbol{\mu}$")
plt.show()                              

In addition, I had to tell the siunitx package to detect the font family, and I also had to add some additional text to the x-label in order for the detection to actually work (you can remove this text later and the label will still work after that).

For me this results in: More generally, I have the following my ~/.matplotlib/matploblibrc file, for serif fonts:

font.family    : serif 
text.latex.preamble    :   \usepackage{mathptmx}

and for sans-serif:

font.family : sans-serif 
text.latex.preamble :   \usepackage{sfmath}