matplotlib tutorial (10) nitta@tsuda.ac.jp

Chapter 10: Pie Chart / Circle Graph

10-1: Drawing a circle graph pyplot.pie

Create a circle graph using pyplot.pie()

# sample code 10-1
%matplotlib inline

import matplotlib.pyplot as plt
import numpy as np

values = [10, 20, 25, 30, 50]
labels = ['Apple', 'Banana', 'Grape', 'Oange', 'Pineapple']

fig, ax = plt.subplots(1,1,figsize=(6,4))
ax.pie(
    x=values,
    labels=labels,
    autopct='%.2f%%'   # display up to 2 digits after the decimal point
)
ax.axis('equal') # not ellipse

plt.show()

10-2: Circle Graph displayed clockwise with a start angle of 90 degree

# sample code 10-2
%matplotlib inline

import matplotlib.pyplot as plt
import numpy as np

values = [10, 20, 25, 30, 50]
labels = ['Apple', 'Banana', 'Grape', 'Oange', 'Pineapple']

fig, ax = plt.subplots(1,1,figsize=(6,4))
ax.pie(
    x=values,
    labels=labels,
    autopct='%.2f%%',
    startangle=90,       # start from 90 degree (12 o'clock) position
    counterclock=False   # clockwise
)
ax.axis('equal') # not ellipse

plt.show()

10-3: Set element color, width of edge line, and color of color label text

# sample code 10-3
%matplotlib inline

import matplotlib.pyplot as plt
import numpy as np

values = [10, 20, 25, 30, 50]
labels = ['Apple', 'Banana', 'Grape', 'Oange', 'Pineapple']
colors = ['red', 'violet', 'deeppink', 'fuchsia', 'deeppink', 'pink']

fig, ax = plt.subplots(1, 1, figsize=(6,4))

ax.pie(
    x=values,
    labels=labels,
    colors=colors,
    wedgeprops={
        'linewidth': 3,
        'edgecolor':'white'
    },
    labeldistance=0.5,
    textprops={
        'color':'white',
        'weight':'bold'
    }
)
plt.axis('equal')
plt.show()

10-4: Cut out a specific element to make it stand out

# sample code 10-4
%matplotlib inline

import matplotlib.pyplot as plt
import numpy as np

values = [10, 20, 25, 30, 50]
labels = ['Apple', 'Banana', 'Grape', 'Oange', 'Pineapple']
explodes = [0.4, 0, 0, 0.1, 0]

fig, ax = plt.subplots(1,1,figsize=(6,4))
ax.pie(
    x=values,
    labels=labels,
    autopct='%.2f%%',
    explode=explodes
)
ax.axis('equal') # not ellipse

plt.show()