Make filled polygons between two horizontal curves in Python using 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.

To create filled polygons between two curves a PolyCollection filling needs to be created between y1 and y2.

Parameters for the above task:

• x: It is an array of length N that holds data of x.
• y1: It is an array or a scalar of length N that holds data of y.
• y2: It is an array or a scalar of length N that holds data of y.

Below is the implementation.

import matplotlib.pyplot as plt


x_inp= input("Enter values of X array:  ").split()
x= [int(i) for i in x_inp]

y1_inp= input("Enter values of Y1 array:  ").split()
y1= [int(i) for i in y1_inp]

y2_inp= input("Enter values of Y2 array:  ").split()
y2= [int(i) for i in y2_inp]

color=input("Enter color:  ")

plt.fill_between(x, y1, y2, color = color)
plt.show()

For input:

Enter values of X array:  1 2 3
Enter values of Y1 array:  1 2 1
Enter values of Y2 array:  1 4 1
Enter color:  red

Output :

For input:

Enter values of X array:  1 2 3 4 5
Enter values of Y1 array:  1 2 3 2 1
Enter values of Y2 array:  3 5 7 5 3
Enter color:  blue

Output :