How to plot a complex number in Python using Matplotlib ?

Last Updated : 03 Jan, 2021

In this article we will learn how to plot complex number in Python using Matplotlib. Let’s discuss some concepts :

Matplotlib : Matplotlib is an amazing visualization library in Python for 2D plots of arrays. Matplotlib is a multi-platform data visualization library built on NumPy arrays and designed to work with the broader SciPy stack. It was introduced by John Hunter in the year 2002.
Complex number : A complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i represents the imaginary unit, satisfying the equation i2 = −1. Because no real number satisfies this equation, i is called an imaginary number.
Complex number in Python : An complex number is represented by “ x + yi “. Python converts the real numbers x and y into complex using the function complex(x,y). The real part can be accessed using the function real() and imaginary part can be represented by imag().

Approach:

Import libraries.
Create data of complex numbers
Extract real and imaginary parts from complex numbers data
Plot the extracted data.

Examples:

To plot complex numbers, we have to extract its real and imaginary part and to extract and create data, we will use some methods that are explained in below examples :

Example 1 : (Simple plot with complex numbers over real and imaginary data)

Python3

# import library 
import matplotlib.pyplot as plt 
  
# create data of complex numbers 
data = [1+2j, -1+4j, 4+3j, -4, 2-1j, 3+9j, -2+6j, 5] 
  
# extract real part 
x = [ele.real for ele in data] 
# extract imaginary part 
y = [ele.imag for ele in data] 
  
# plot the complex numbers 
plt.scatter(x, y) 
plt.ylabel('Imaginary') 
plt.xlabel('Real') 
plt.show() 

Output :

Example 2 : (Using numpy for extracting real and imaginary parts)

Python3

# import libraries 
import matplotlib.pyplot as plt 
import numpy as np 
  
# create data of complex numbers 
data = np.array([1+2j, 2-4j, -2j, -4, 4+1j, 3+8j, -2-6j, 5]) 
  
# extract real part using numpy array 
x = data.real 
# extract imaginary part using numpy array 
y = data.imag 
  
# plot the complex numbers 
plt.plot(x, y, 'g*') 
plt.ylabel('Imaginary') 
plt.xlabel('Real') 
plt.show() 

Output :

Example 3 : (Using numpy for creating data of complex numbers and extracting real and imaginary parts)

Python3

# import libraries 
import matplotlib.pyplot as plt 
import numpy as np 
  
# create data of complex numbers using numpy 
data = np.arange(8) + 1j*np.arange(-4, 4) 
  
# extract real part using numpy 
x = data.real 
# extract imaginary part using numpy 
y = data.imag 
  
# plot the complex numbers 
plt.plot(x, y, '-.r*') 
plt.ylabel('Imaginary') 
plt.xlabel('Real') 
plt.show() 