Subtracting one matrix from another using numpy.ndarray with Example

Overview:

For subtracting one matrix from another matrix, the dimensions of both the matrices should be equal.
Subtraction of two matrices is similar to adding two matrices.
To subtract Matrix-B from Matrix-A, subtract each entry of Matrix-B from the corresponding entry of Matrix-A and place the result in the same position of the new matrix.
The numpy.ndarray has __sub__() method which subtracts one ndarray object from another and returns the resultant ndarray object.

Example:

# import numpy module

import numpy as np

# import python standard library module - random

import random

# Function to populate a matrix with random data

def FillMatrix(matrix_in):

for x in range(0, matrix_in.shape[0]):

for y in range(0, matrix_in.shape[1]):

matrix_in[x][y] = random.randrange(2, 10) + 2

# Create two 4x4 matrices using ndarray

matrix1 = np.ndarray((4,4))

matrix2 = np.ndarray((4,4))

# Fill the matrices i.e., the two dimensional arrays created using ndarray objects

FillMatrix(matrix1)

FillMatrix(matrix2)

# Add two matrices - two nd arrays

add_results = matrix1.__sub__(matrix2)

# Print Matrix1

print("Matrix1:")

print(matrix1)

# Print Matrix2

print("Matrix2:")

print(matrix2)

# Print the results of subtracting two matrices

print("Result of subtracting Matrix1 and Matrix2:")

print(add_results)

Output:

Matrix1:

[[ 5. 9. 5. 8.]

[ 4. 10. 11. 9.]

[ 9. 5. 6. 5.]

[ 10. 10. 10. 8.]]

Matrix2:

[[ 9. 10. 9. 4.]

[ 9. 6. 8. 4.]

[ 9. 11. 11. 4.]

[ 6. 4. 8. 11.]]

Result of subtracting Matrix1 and Matrix2:

[[-4. -1. -4. 4.]

[-5. 4. 3. 5.]

[ 0. -6. -5. 1.]

Subtracting one matrix from another using numpy.ndarray with Example

Overview:

Example:

Output:

[ 4. 6. 2. -3.]]