#12 Stacked barplot with matplotlib

If you have groups and subgroups, you probably want to display the subgroups values in a grouped barplot or a stacked barplot. In the first case, subgroups are displayed one beside each other, in the second case subgroups are displayed on top of each other.

Here is a code showing how to do a stacked barplot. Note that it can easily be turned as a stacked percent barplot.

# libraries
import numpy as np
import matplotlib.pyplot as plt
from matplotlib import rc
import pandas as pd

# y-axis in bold
rc('font', weight='bold')

# Values of each group
bars1 = [12, 28, 1, 8, 22]
bars2 = [28, 7, 16, 4, 10]
bars3 = [25, 3, 23, 25, 17]

# Heights of bars1 + bars2
bars = np.add(bars1, bars2).tolist()

# The position of the bars on the x-axis
r = [0,1,2,3,4]

# Names of group and bar width
names = ['A','B','C','D','E']
barWidth = 1

# Create brown bars
plt.bar(r, bars1, color='#7f6d5f', edgecolor='white', width=barWidth)
# Create green bars (middle), on top of the firs ones
plt.bar(r, bars2, bottom=bars1, color='#557f2d', edgecolor='white', width=barWidth)
# Create green bars (top)
plt.bar(r, bars3, bottom=bars, color='#2d7f5e', edgecolor='white', width=barWidth)

# Custom X axis
plt.xticks(r, names, fontweight='bold')
plt.xlabel("group")

# Show graphic
plt.show()