How to create a Crosstab Plot?-CodePudding

I would like to create a 'Crosstab' plot like the below using matplotlib or seaborn:

Using the following dataframe:

import pandas as pd

data = [['A', 'C', 2], ['A', 'D', 8], ['B', 'C', 25], ['B', 'D', 30]]
df = pd.DataFrame(data = data, columns = ['col', 'row', 'val'])

  col row  val
0   A   C    2
1   A   D    8
2   B   C   25
3   B   D   30

An option in matplotlib could be by adding Rectangles to the origin via plt.gca and add_patch. The problem is that I did here all manually like this:

from matplotlib.patches import Rectangle
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_axes([0, 0, 1, 1])
plt.xlim(-10, 40)
plt.ylim(-40, 40)
plt.rcParams['figure.figsize'] = (10,16)

someX, someY = 0, 0
currentAxis = plt.gca()
currentAxis.add_patch(Rectangle((someX, someY), 30, 30, facecolor="purple"))
ax.text(15, 15, '30')
currentAxis.add_patch(Rectangle((someX, someY), 25, -25, facecolor="blue"))
ax.text(12.5, -12.5, '25')
currentAxis.add_patch(Rectangle((someX, someY), -2, -2, facecolor="red"))
ax.text(-1, -1, '2')
currentAxis.add_patch(Rectangle((someX, someY), -8, 8, facecolor="green"))
ax.text(-4, 4, '8')

Output:

As you can see, the plot doesn't look that nice. So I was wondering if it is possible to somehow automatically create 'Crosstab' plots using matplotlib or seaborn?

CodePudding user response：

I am not sure whether matplotlib or seaborn have dedicated functions for this type of plot or not, but using plt.bar and plt.bar_label instead of Rectangle and plt.Text might help automatize things a little (label placement etc.).

See code below:

import matplotlib.pyplot as plt

data = [['A', 'C', 2], ['A', 'D', 8], ['B', 'C', 25], ['B', 'D', 30]]
pos={'A':-1,'B':0,'C':-1,'D':1} 
fig,ax=plt.subplots(figsize=(10,10))
p=[ax.bar(pos[d[0]]*d[2],pos[d[1]]*d[2],width=d[2],align='edge') for d in data]
[ax.bar_label(p[i],labels=[data[i][2]], label_type='center',fontsize=18) for i in range(len(data))]
ax.set_aspect('equal')