Matplotlib Bar Chart: Create stack bar plot and add label to each section

Matplotlib Bar Chart: Exercise-16 with Solution

Write a Python program to create stack bar plot and add label to each section.

Sample data:
people = ('G1','G2','G3','G4','G5','G6','G7','G8')
segments = 4
# multi-dimensional data
data = [[ 3.40022085, 7.70632498, 6.4097905, 10.51648577, 7.5330039, 7.1123587, 12.77792868, 3.44773477],
[ 11.24811149, 5.03778215, 6.65808464, 12.32220677, 7.45964195, 6.79685302, 7.24578743, 3.69371847],
[ 3.94253354, 4.74763549, 11.73529246, 4.6465543, 12.9952182, 4.63832778, 11.16849999, 8.56883433],
[ 4.24409799, 12.71746612, 11.3772169, 9.00514257, 10.47084185, 10.97567589, 3.98287652, 8.80552122]]

Sample Solution:

Python Code:

import numpy as np
import matplotlib.pyplot as plt

people = ('G1','G2','G3','G4','G5','G6','G7','G8')
segments = 4

# multi-dimensional data 
data = [[  3.40022085,   7.70632498,   6.4097905,   10.51648577,   7.5330039,
    7.1123587,   12.77792868,   3.44773477],
 [ 11.24811149,   5.03778215,   6.65808464,  12.32220677,   7.45964195,
    6.79685302,   7.24578743,   3.69371847],
 [  3.94253354,   4.74763549,  11.73529246,   4.6465543,   12.9952182,
    4.63832778,  11.16849999,   8.56883433],
 [  4.24409799,  12.71746612,  11.3772169,    9.00514257,  10.47084185,
   10.97567589,   3.98287652,   8.80552122]]
percentages = (np.random.randint(5,20, (len(people), segments)))
y_pos = np.arange(len(people))

fig = plt.figure(figsize=(10,8))
ax = fig.add_subplot(111)

colors ='rgwm'
patch_handles = []
# left alignment of data starts at zero
left = np.zeros(len(people)) 
for i, d in enumerate(data):
    patch_handles.append(ax.barh(y_pos, d, 
      color=colors[i%len(colors)], align='center', 
      left=left))
    left += d

# search all of the bar segments and annotate
for j in range(len(patch_handles)):
    for i, patch in enumerate(patch_handles[j].get_children()):
        bl = patch.get_xy()
        x = 0.5*patch.get_width() + bl[0]
        y = 0.5*patch.get_height() + bl[1]
        ax.text(x,y, "%d%%" % (percentages[i,j]), ha='center')

ax.set_yticks(y_pos)
ax.set_yticklabels(people)
ax.set_xlabel('Scores')
plt.show()

Sample Output:

Python Code Editor:

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