Python Program to multiply 2D array and Scalar using Broadcasting

Last update on March 26 2025 13:15:52 (UTC/GMT +8 hours)

12. Scalar Multiplication on a 2D Array

Write a NymPy program that creates a 2D array x of shape (4, 4) and a scalar y. Perform element-wise multiplication of a and b using broadcasting.

Sample Solution:

Python Code:

import numpy as np

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

# Initialize the scalar
y = 3

# Perform element-wise multiplication using broadcasting
result_array = x * y

# Display the result
print(result_array)

Output:

[[ 3  6  9 12]
 [15 18 21 24]
 [27 30 33 36]
 [39 42 45 48]]

Explanation:

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

For more Practice: Solve these Related Problems:

• Multiply a 2D array by a scalar value using broadcasting and then compute the sum of the resulting array.
• Create a function that scales a 2D array by a given scalar and verifies that the array’s shape remains unchanged.
• Implement a solution that multiplies a 2D array by a scalar and then adds a constant to each element for further transformation.
• Test the scalar multiplication on arrays with various dtypes to ensure consistent type promotion.

Python-Numpy Code Editor:

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