NumPy: Create a 3-D array with ones on the diagonal and zeros elsewhere

Last update on March 24 2025 13:37:10 (UTC/GMT +8 hours)

3D Array with Diagonal Ones

Write a NumPy program to create a 3-D array with ones on a diagonal and zeros elsewhere.

Pictorial Presentation:

Sample Solution:

Python Code:

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

# Creating a 3x3 identity matrix using the eye method in NumPy
x = np.eye(3)

# Printing the created identity matrix
print(x)

Sample Output:

[[ 1.  0.  0.]                                                         
 [ 0.  1.  0.]                                                         
 [ 0.  0.  1.]]

Explanation:

The above code demonstrates how to create an identity matrix (a square matrix with ones on the diagonal and zeros elsewhere) using the np.eye() function in NumPy.

x = np.eye(3): np.eye(3This line creates a 3x3 identity matrix x using the np.eye() function. The function takes one argument, which is the number of rows (and columns, since it's a square matrix) in the resulting identity matrix.

print(x): This line prints the identity matrix x:

For more Practice: Solve these Related Problems:

• Create a 3D array where each 2D sub-array is an identity matrix using np.eye in a loop or comprehension.
• Write a function that generates a 3D array with diagonal ones for any given square dimension and depth.
• Validate that every 2D slice of the 3D array contains ones on the main diagonal and zeros elsewhere.
• Extend the concept to create a 3D array where only a specific cross-section diagonal is set to one.

Python-Numpy Code Editor: