NumPy: Create a 3x3 identity matrix

Last update on August 28 2025 12:36:47 (UTC/GMT +8 hours)

Create 3x3 Identity Matrix

Write a NumPy program to create a 3x3 identity matrix.

This NumPy program generates a 3x3 identity matrix, which is a square matrix with ones on the main diagonal and zeros elsewhere. By using NumPy's built-in functions, it efficiently constructs this matrix. This program exemplifies how to create standard mathematical matrices in a straightforward manner using NumPy.

Sample Solution :

Python Code :

# Importing the NumPy library with an alias 'np'
import numpy as np

# Creating a 3x3 identity matrix using np.identity()
array_2D = np.identity(3)

# Printing a message indicating a 3x3 matrix
print('3x3 matrix:')

# Printing the 3x3 identity matrix
print(array_2D) 

Sample Output:

3x3 matrix:
[[ 1.  0.  0.]
 [ 0.  1.  0.]
 [ 0.  0.  1.]]                         

Explanation:

In the above code np.identity() function creates a 2D identity matrix with a size of 3x3. An identity matrix is a square matrix with ones on the diagonal and zeros elsewhere.

Visual Presentation:

For more Practice: Solve these Related Problems:

• Generate a 4x4 identity matrix using np.eye and validate the diagonal elements.
• Create an identity matrix and then modify one of its diagonal elements.
• Construct an identity matrix with an offset diagonal using np.eye with k parameter.
• Use np.identity to create a 3x3 matrix and compute its determinant.

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