Matplotlib - How do I set ylim() for a series of plots?

Question

I have a series of box plots I am trying to make, each of which has a different range. I tried setting ylim by determining the max and min of each separate series. Howe

Answer 1

As an alternative to what @unutbu suggested, you could avoid plotting the outliers and then use ax.margins(y=0) (or some small eps) to scale the limits to the range of the whiskers.

For example:

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

df = pd.DataFrame(np.random.poisson(5, size=(100, 5)))

fig, ax = plt.subplots()
#Note showfliers=False is more readable, but requires a recent version iirc
box = df.boxplot(ax=ax, sym='') 
ax.margins(y=0)
plt.show()

And if you'd like a bit of room around the largest "whiskers", use ax.margins(0.05) to add 5% of the range instead of 0% of the range:

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

df = pd.DataFrame(np.random.poisson(5, size=(100, 5)))

fig, ax = plt.subplots()
box = df.boxplot(ax=ax, sym='')
ax.margins(y=0.05)
plt.show()