Setting math font when using mpl.Figure.figure

[Auerilas]

Hi,
I'm using seaborn objects to generate a custom subplotted grid, but the math font defaults to a serif font and I can't figure out how to change it. For example:

from matplotlib import style
import seaborn.objects as so
from os import chdir
theme = {**style.library['bmh'],
		'xtick.bottom': True,
		'ytick.left': True,
		'mathtext.default': 'regular'}

chdir('/home/nate/Downloads')
df = pd.read_csv('Soil_Ions_March2024.csv')
df_onoff = df.loc[(df['Distance.m']==0.0) | (df['Distance.m']==15.0)]
df_onoff['Trt'] = df_onoff['Distance.m'].map({0.0: 'Carcass', 15.0: 'Matrix'})

g = (so.Plot(x='Trt', y='NH4.mgkg', color='Trt', data=df_onoff)
     .add(so.Bar(), so.Est(), legend=False)
     .add(so.Range(), so.Est(errorbar='se'), legend=False)
     .layout(size=(4,6))
     .label(x='', y='Soil NH$_4$ (mg/kg)')
     .scale(x=so.Nominal(order=['Matrix', 'Carcass']),
            color=so.Nominal('colorblind'))
     .theme(theme)
     )

produces the figure I like (Fig 1).

But then:

import matplotlib as mpl
f = mpl.figure.Figure(figsize=(6.5, 3), dpi=300, layout="constrained")
sf1, sf2, sf3 = f.subfigures(1, 3)

g = (so.Plot(x='Trt', y='NH4.mgkg', color='Trt', data=df_onoff)
     .add(so.Bar(), so.Est(), legend=False)
     .add(so.Range(), so.Est(errorbar='se'), legend=False)
     .layout(size=(4,6))
     .label(x='', y='Soil NH$_4$ (mg/kg)')
     .scale(x=so.Nominal(order=['On', 'Off']),
            color=so.Nominal('colorblind'))
     .theme(theme)
     )
g.on(sf1).plot()

g2 = (so.Plot(x='Trt', y='NO3.mgkg', color='Trt', data=df_onoff)
     .add(so.Bar(), so.Est(), legend=False)
     .add(so.Range(), so.Est(errorbar='se'), legend=False)
     .layout(size=(4,6))
     .label(x='', y='Soil NO$_3$ (mg/kg)')
     .scale(x=so.Nominal(order=['On', 'Off']),
            color=so.Nominal('colorblind'))
     .theme(theme)
     )
g2.on(sf2).plot()

g3 = (so.Plot(x='Trt', y='PO4.mgkg', color='Trt', data=df_onoff)
     .add(so.Bar(), so.Est(), legend=False)
     .add(so.Range(), so.Est(errorbar='se'), legend=False)
     .layout(size=(4,6))
     .label(x='', y='Soil PO$_4$ (mg/kg)')
     .scale(x=so.Nominal(order=['On', 'Off']),
            color=so.Nominal('colorblind'))
     .theme(theme)
     )
g3.on(sf3).plot()

f.savefig('fig2.png', bbox_inches='tight')

produces Fig 2, which has weird serif math fonts for the numbers. I know from the API that g.on() can revert to the underlying rcParams, but I have tried everything:

plt.style.use(so.Plot.config.theme), plt.rcParams = so.Plot.config.theme, etc.

I just can't seem to figure out how to fix the math font.

Is there a way to fix this/perhaps upload an example to the API?
Thanks!

[MaozGelbart]

Hi @Auerilas , this is not seaborn related. See here for a solution.