How to Draw a Circle Using Matplotlib in Python?

Last Updated : 26 Nov, 2020

A Circle is a mathematical figure formed by joining all points lying on the same plane and are at equal distance from a given point. We can plot a circle in python using Matplotlib. There are multiple ways to plot a Circle in python using Matplotlib.

Method 1: Using matplotlib.patches.Circle() function.

Matplotlib has a special function matplotlib.patches.Circle() in order to plot circles.

Syntax: class matplotlib.patches.Circle(xy, radius=5, **kwargs)

Example 1: Plotting a colored Circle using matplotlib.patches.Circle()

Python3

# Demonstrating use of matplotlib.patches.Circle() functiion 
# to plot a colored Circle 
  
import matplotlib.pyplot as plt 
  
figure, axes = plt.subplots() 
Drawing_colored_circle = plt.Circle(( 0.6 , 0.6 ), 0.2 ) 
  
axes.set_aspect( 1 ) 
axes.add_artist( Drawing_colored_circle ) 
plt.title( 'Colored Circle' ) 
plt.show() 

Output:

Example 2: Plotting an un-colored Circle using matplotlib.patches.Circle()

Python3

# Demonstrating use of matplotlib.patches.Circle() functiion 
# to plot an un-colored Circle 
  
import matplotlib.pyplot as plt 
  
figure, axes = plt.subplots() 
Drawing_uncolored_circle = plt.Circle( (0.6, 0.6 ), 
                                      0.3 , 
                                      fill = False ) 
  
axes.set_aspect( 1 ) 
axes.add_artist( Drawing_uncolored_circle ) 
plt.title( 'Circle' ) 
plt.show() 

Output:

Method 2: Using Circle Equation

Example 1: Plotting a Circle using Parametric equation of a circle

Python3

# Program to plot a Circle 
# using Parametric equation of a Circle 
  
import numpy as np 
import matplotlib.pyplot as plt 
  
theta = np.linspace( 0 , 2 * np.pi , 150 ) 
  
radius = 0.4
  
a = radius * np.cos( theta ) 
b = radius * np.sin( theta ) 
  
figure, axes = plt.subplots( 1 ) 
  
axes.plot( a, b ) 
axes.set_aspect( 1 ) 
  
plt.title( 'Parametric Equation Circle' ) 
plt.show() 

Output:

Example 2: Using Center-Radius form of a circle equation

Python3

# Program to plot a Circle 
# using Center-Radius form of circle equation 
  
import numpy as np 
import matplotlib.pyplot as plt 
  
x = np.linspace( -0.7 , 0.7 , 150 ) 
y = np.linspace( -0.7 , 0.7 , 150 ) 
  
a, b = np.meshgrid( x , y ) 
  
C = a ** 2 + b ** 2 - 0.2
  
figure, axes = plt.subplots() 
  
axes.contour( a , b , C , [0] ) 
axes.set_aspect( 1 ) 
  
plt.title( 'Center-Radius form Circle' ) 
plt.show() 

Output:

Method 3: Using the Scatter Plot of points

Example:

Python3

# Program to plot a Circle 
# using Scatter plot of points 
  
import matplotlib.pyplot as plt 
  
plt.scatter( 0 , 0 , s = 7000 ) 
plt.title( 'Circle' ) 
  
plt.xlim( -0.85 , 0.85 ) 
plt.ylim( -0.95 , 0.95 ) 
  
plt.title( "Scatter plot of points Circle" ) 
plt.show() 