Examining both distribution shape and outliers with violin plots

Violin plots combine histograms and boxplots in one plot. They show the IQR, median, and whiskers, as well as the frequency of observations at all ranges of values. It is hard to visualize how that is possible without seeing an actual violin plot. We generate a few violin plots on the same data we used for boxplots in the previous recipe, to make it easier to grasp how they work.

Getting ready

We will work with the NLS data. You need Matplotlib and Seaborn installed on your computer to run the code in this recipe.

How to do it…

We do violin plots to view both the spread and shape of the distribution on the same graphic. We then do violin plots by groups:

1. Load pandas, matplotlib, and seaborn, and the NLS data:

   import pandas as pd
   import numpy as np
   import matplotlib.pyplot as plt
   import seaborn as sns
   nls97 = pd.read_csv("data/nls97f.csv", low_memory=False)
   nls97.set_index...