Seaborn FacetGrid with mosaic plot

Question

Trying to plot a grid of mosaic plots using Seaborn's FacetGrid and statsmodels' mosaic and not quite making it.

Example dataset:

import pandas as pd
import numpy as np
import seaborn as sns
import matplotlib.pyplot as plt
from statsmodels.graphics.mosaicplot import mosaic

index = [i for j in [[k] * 6 for k in range(4)] for i in j]
gender = ['male', 'male', 'male', 'female', 'female', 'female'] * 4
pet = np.random.choice(['cat', 'dog'], 24).tolist()
data = pd.DataFrame({'index': index, 'gender': gender, 'pet': pet})
data.head(10)

    index   gender  pet
0   0   male    dog
1   0   male    dog
2   0   male    cat
3   0   female  dog
4   0   female  dog
5   0   female  cat
6   1   male    cat
7   1   male    dog
8   1   male    dog
9   1   female  dog

I want to make a 2x2 grid of 4 mosaic plots, each for the subset of column index.

Now, a single mosaic plot of say the first group (index == 0):

data0 = data[data['index'] == 0]

props = {}
for x in ['female', 'male']:
    for y, col in {'dog': 'red', 'cat': 'blue'}.items():
        props[(x, y)] ={'color': col}

mosaic(data0, ['gender', 'pet'],
       labelizer=lambda k: '',
       properties=props)
plt.show()

But trying to put this mosaic in a custom function sns.FacetGrid.map() could use, I fail (this is one version, I tried a few):

def my_mosaic(sliced_data, **kwargs):
    mosaic(sliced_data, ['gender', 'pet'],
       labelizer=lambda k: '',
       properties=props)

g = sns.FacetGrid(data, col='index', col_wrap=2)
g = g.map(my_mosaic)

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-323-a81a61aaeaff> in <module>()
      5 
      6 g = sns.FacetGrid(data, col='index', col_wrap=2)
----> 7 g = g.map(my_mosaic)

~\AppData\Local\Programs\Python\Python36-32\lib\site-packages\seaborn\axisgrid.py in map(self, func, *args, **kwargs)
    741 
    742             # Draw the plot
--> 743             self._facet_plot(func, ax, plot_args, kwargs)
    744 
    745         # Finalize the annotations and layout

~\AppData\Local\Programs\Python\Python36-32\lib\site-packages\seaborn\axisgrid.py in _facet_plot(self, func, ax, plot_args, plot_kwargs)
    825 
    826         # Draw the plot
--> 827         func(*plot_args, **plot_kwargs)
    828 
    829         # Sort out the supporting information

TypeError: my_mosaic() missing 1 required positional argument: 'sliced_data'

I read the documentation and examples, but I just couldn't figure out how to make a callable function from any plotting function which isn't built-in in Seaborn or in matplotlib.pyplot (e.g. plt.scatter or sns.regplot).

Answer 1

I found it is easier to use map_dataframe() when you are ultimately dealing with... dataframes.

def my_mosaic(*args,**kwargs):
    mosaic(kwargs['data'], list(args),
           labelizer=lambda k: '',
           properties=props,
           ax=plt.gca())

g = sns.FacetGrid(data, col='index', col_wrap=2)
g = g.map_dataframe(my_mosaic, 'gender', 'pet')