Theprogrammersfirst: How to adjust the ticks and label size of a pandas plot with secondary

2021-11-28

How to adjust the ticks and label size of a pandas plot with secondary_y

I have a plot with a left and right y-axis created with pandas.DataFrame.plot and specifying secondary_y=True.

I want to increase the font sizes of the y-axis tick params, but it seems that only the left side y-axis font size is increasing.

import pandas as pd
import numpy as np

# sample dataframe
sample_length = range(1, 2+1)
rads = np.arange(0, 2*np.pi, 0.01)
data = np.array([np.sin(t*rads) for t in sample_length])
df = pd.DataFrame(data.T, index=pd.Series(rads.tolist(), name='radians'), columns=[f'freq: {i}x' for i in sample_length])

# display(df.head(3))
         freq: 1x  freq: 2x
radians                    
0.00     0.000000  0.000000
0.01     0.010000  0.019999
0.02     0.019999  0.039989

# plot
ax1 = df.plot(y='freq: 1x', ylabel='left-Y')
ax2 = df.plot(y='freq: 2x', secondary_y=True, ax=ax1)