Matplotlib 2 inconsistent font

Question

I updated Anaconda Python to the latest version (4.3), where they upgraded Matplotlib to version 2.

The upgrade has made some major changes to the default style (see

Answer 1

While trying to find a solution to my question, I tried comparing the dictionaries of the old and new rcParams and setting the elements which were different and related to mathtext font: the result is quite good.

The code is:

#%matplotlib inline
#%matplotlib notebook
#%config InlineBackend.figure_format = 'svg'
import scipy as sc
import matplotlib.pyplot as plt
import matplotlib

# http://matplotlib.org/users/dflt_style_changes.html
params = {'legend.fontsize': 18,
          'axes.labelsize': 18,
          'axes.titlesize': 18,
          'xtick.labelsize' :12,
          'ytick.labelsize': 12,
          'mathtext.fontset': 'cm',
          'mathtext.rm': 'serif',
          'mathtext.bf': 'serif:bold',
          'mathtext.it': 'serif:italic',
          'mathtext.sf': 'sans\\-serif',
          'grid.color': 'k',
          'grid.linestyle': ':',
          'grid.linewidth': 0.5,
         }
matplotlib.rcParams.update(params)
#matplotlib.rcParams.update({'text.usetex':True, 'text.latex.preamble':[r'\usepackage{amsmath, newtxmath}']})
#matplotlib.rcParams.update({'text.usetex':True, 'text.latex.preamble':[r'\usepackage{amsmath, mathptmx}']})
#matplotlib.rcParams.update({'text.usetex':True, 'text.latex.preamble':[r'\usepackage{amsmath}']})

x = sc.linspace(0,100)
y = x**2
fig = plt.figure('Fig')
ax = fig.add_subplot(1, 1, 1)
lines = ax.semilogy(x, y)
ax.set_yticks([300], minor=True)
ax.yaxis.grid(True, which='minor')
ax.yaxis.set_minor_formatter(matplotlib.ticker.ScalarFormatter())
ax.tick_params(axis='y', pad=10)
ax.set_xlabel(r'$\mathrm{R_L}$')
ax.set_ylabel(r'$\sigma \int_l \; dx$')
fig.savefig('./PNG/test.png', dpi=300, bbox_inches='tight')

hence adding also:

          'mathtext.rm': 'serif',
          'mathtext.bf': 'serif:bold',
          'mathtext.it': 'serif:italic',
          'mathtext.sf': 'sans\\-serif',

which results in:

that I consider quite good and consistent in a Latex document.

The other answer in this thread from @ImportanceOfBeingErnest is also neat and nice.