Adding and Subtracting Matrices in Python

In this article, we will discuss how to add and subtract elements of the matrix in Python. 

Example:

Suppose we have two matrices A and B.
A = [[1,2],[3,4]]
B = [[4,5],[6,7]]

then we get
A+B = [[5,7],[9,11]]
A-B = [[-3,-3],[-3,-3]]

Now let us try to implement this using Python 

1. Adding elements of the matrix

In the above code, we have used np.add() method to add elements of two matrices. If shape of two arrays are not same, that is arr1.shape != arr2.shape, they must be broadcastable to a common shape (which may be the shape of one or the other).

Python3

# importing numpy as np
import numpy as np


# creating first matrix
A = np.array([[1, 2], [3, 4]])

# creating second matrix
B = np.array([[4, 5], [6, 7]])

print("Printing elements of first matrix")
print(A)
print("Printing elements of second matrix")
print(B)

# adding two matrix
print("Addition of two matrix")
print(np.add(A, B))

Output:

Printing elements of first matrix
[[1 2]
 [3 4]]
Printing elements of second matrix
[[4 5]
 [6 7]]
Addition of two matrix
[[ 5  7]
 [ 9 11]]

2. Subtracting elements of matrices

In the above code, we have used np.subtract() to subtract elements of two matrices. It returns the difference of arr1 and arr2, element-wise.

Python3

# importing numpy as np
import numpy as np


# creating first matrix
A = np.array([[1, 2], [3, 4]])

# creating second matrix
B = np.array([[4, 5], [6, 7]])

print("Printing elements of first matrix")
print(A)
print("Printing elements of second matrix")
print(B)

# subtracting two matrix
print("Subtraction of two matrix")
print(np.subtract(A, B))

Output:

Printing elements of first matrix
[[1 2]
 [3 4]]
Printing elements of second matrix
[[4 5]
 [6 7]]
Subtraction of two matrix
[[-3 -3]
 [-3 -3]]