Unable To Control Scale Of Second Y-axis On Df.plot()

I am trying to plot 3 series with 2 on the left y-axis and 1 on the right using secondary_y, but it’s not clear to me how to define the right y-axis scale as I did on the left wi

Solution 1:

You need to use set_ylim on the appropriate ax.

For example:

ax2 = ax1.twinx()
ax2.set_ylim(bottom=-10, top=10)

Also, reviewing your code, it appears that you are specifying your iloc columns incorrectly. Try:

ax1.plot(df.index, df.iloc[:, :2])  # Columns0 and 1.
ax2.plot(df.index, df.iloc[:, 2])   # Column 2.

Solution 2:

import matplotlib.pyplot as plt
import pandas as pd
import numpy as np

df = pd.DataFrame(np.random.randn(10,3))
print (df)
fig, ax1 = plt.subplots()

ax2 = ax1.twinx()
ax1.plot(df.index,df.iloc[:,[0,2]])
ax2.plot(df.index, df.iloc[:,2])

plt.show()

Solution 3:

You can do this without directly calling ax.twinx():

#Plot the first series on the LH y-axis
ax1 = df.plot('x_column','y1_column')

#Add the second series plot, and grab the RH axis
ax2 = df.plot('x_column','y2_column',ax=ax1)
ax2.set_ylim(0,10)

Note: Only tested in Pandas 19.2