MSE.py

#Import needed libraries
import matplotlib.pyplot as plt
#Set data
x = list(range(1,6)) #data points
y = [1,1,2,2,4]  #original values  
y_bar = [0.6,1.29,1.99,2.69,3.4]  #predicted values
summation = 0 
n = len(y) 
for i in range(0, n):  
    # finding the difference between observed and predicted value
    difference = y[i] - y_bar[i]
    squared_difference = difference**2  # taking square of the differene
    # taking a sum of all the differences
    summation = summation + squared_difference
MSE = summation/n  # get the average of all
print("The Mean Square Error is: ", MSE)
#Plot relationship
plt.scatter(x, y,  color='#06AED5')
plt.plot(x, y_bar, color='#1D3557', linewidth=2)
plt.xlabel('Data Points', fontsize=12)
plt.ylabel('Output', fontsize=12)
plt.title("MSE")