Numpy Program to multiply each row of 2D array by 1D array using Broadcasting

Last update on December 21 2024 07:37:10 (UTC/GMT +8 hours)

Write a NumPy program that multiplies each row of a 2D array a of shape (4, 4) by a 1D array b of shape (4,) using broadcasting.

Sample Solution:

Python Code:

import numpy as np

# Initialize the 2D array of shape (4, 4)
a = np.array([[1, 2, 3, 4],
              [5, 6, 7, 8],
              [9, 10, 11, 12],
              [13, 14, 15, 16]])

# Initialize the 1D array of shape (4,)
b = np.array([2, 4, 6, 8])

# Perform element-wise multiplication using broadcasting
result_array = a * b

# Display the result
print(result_array)

Output:

[[  2   8  18  32]
 [ 10  24  42  64]
 [ 18  40  66  96]
 [ 26  56  90 128]]

Explanation:

• Importing numpy: We first import the numpy library for array manipulations.
• Initializing arrays: A 2D array of shape (4, 4) and a 1D array of shape (4,) are initialized.
• Broadcasting and Multiplication: Element-wise multiplication is performed between each row of the 2D array and the 1D array using broadcasting.
• Displaying result: The resulting array is printed out.

Python-Numpy Code Editor: