# NumPy Matrix Subtraction

Muhammad Maisam Abbas May 24, 2021

This tutorial will discuss the method to perform matrix subtraction operation in NumPy.

## NumPy Matrix Subtraction With the `-` Operator

The infix subtraction operator `-` can be used to perform matrix subtraction in NumPy.

``````import numpy as np

matA = np.matrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
matB = np.matrix([[9, 8, 7], [6, 5, 4], [3, 2, 1]])
matC = matA - matB
print(matC)
``````

Output:

``````[[-8 -6 -4]
[-2  0  2]
[ 4  6  8]]
``````

We subtracted the matrix `matB` from the matrix `matB` with the `-` operator in the above code. We first created the two matrices with the `np.matrix()` function. We then performed matrix subtraction and saved the result inside the matrix `matC` with `matC = matA - matB`.

We can also perform the same subtraction using 2D arrays with the `np.array()` instead of matrices. The following code example shows how to perform matrix subtraction using 2-dimensional arrays.

``````import numpy as np

matA = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
matB = np.array([[9, 8, 7], [6, 5, 4], [3, 2, 1]])
matC = matA - matB
print(matC)
``````

Output:

``````[[-8 -6 -4]
[-2  0  2]
[ 4  6  8]]
``````

The above code gives the same result as the previous example because there is no difference in the `-` operator working with matrices and 2D arrays. It is because the `np.matix` is a subclass of `np.ndarray`.

Maisam is a highly skilled and motivated Data Scientist. He has over 4 years of experience with Python programming language. He loves solving complex problems and sharing his results on the internet.