`inner_kws` having no effect on Seaborn violin plot

Question

I generated a bunch of violin plots, here is an example of one and the code that generates it:

plt.figure(figsize=(8, 4))
ax = sns.violinplot(
    x=data, # `data` is a few thousand float values between 0 and 1
    orient='h',
    color=get_color(ff), # `get_color` returns a color based on the dataset, #FFBE0B in this case
    cut=0
)

I want to make the black box in the middle quite a bit bigger. According to the documentation from Seaborn at https://seaborn.pydata.org/generated/seaborn.violinplot.html, I should be able to do this with the inner_kws parameter. I added this argument to the above code:

plt.figure(figsize=(8, 4))
ax = sns.violinplot(
    x=data, # `data` is a few thousand float values between 0 and 1
    orient='h',
    color=get_color(ff), # `get_color` returns a color based on the dataset, #FFBE0B in this case
    inner_kws=dict(box_width=150, whis_width=20),
    cut=0
)

Above, the box and whisker width are 150 and 20 respectively. I've also tried 15 and 2, and 1500 and 200. No matter what values I enter here, the figure does not change at all. What am I doing wrong?

Answer 1

The inner_kws argument was introduced in version 0.13.0; if you have an older version of seaborn installed it has no effect. I had seaborn v0.12.2 (installed via conda) and your example printed with normal boxplot dimensions until I upgraded seaborn to v0.13.2,

E.g.

#!/usr/bin/env python

import random
import seaborn as sns
import matplotlib.pyplot as plt

data = []
for i in range(0, 1000):
    x = round(random.uniform(0, 1), 4)
    data.append(x)

ax = sns.violinplot(
    x=data, # `data` is a few thousand float values between 0 and 1
    orient='h',
    color='#FFBE0B',
    inner_kws=dict(box_width=100, whis_width=20),
    cut=0
)

plt.savefig("example.png")

Does that solve your problem? Or is there something else causing an issue?