How to reshape a 1D NumPy array to multiple dimensions?

Last update on April 29 2025 12:55:15 (UTC/GMT +8 hours)

6. 1D to 2D to Different Shape Transformation

Write a NumPy program that creates a 1D array of 16 elements, reshape it to (4, 4), then change its shape to (2, 8) without changing the underlying data.

Sample Solution:

Python Code:

import numpy as np

# Create a 1D array of 16 elements
array_1d = np.arange(1, 17)

# Reshape the 1D array to a 2D array of shape (4, 4)
array_2d = array_1d.reshape(4, 4)

# Change the shape of the array to (2, 8) without changing the underlying data
reshaped_array = array_2d.reshape(2, 8)

# Print the reshaped array
print(reshaped_array)

Output:

[[ 1  2  3  4  5  6  7  8]
 [ 9 10 11 12 13 14 15 16]]

Explanation:

Import NumPy library: We start by importing the NumPy library to handle array operations.
Create a 1D array: We create a 1D array array_1d with 16 elements using np.arange(1, 17).
Reshape to (4, 4): We reshape the 1D array to a 2D array array_2d of shape (4, 4) using reshape().
Change shape to (2, 8): We further reshape array_2d to a new shape (2, 8) without changing the underlying data, resulting in reshaped_array.
Print the result: Finally, we print the reshaped_array.

For more Practice: Solve these Related Problems:

Write a NumPy program to reshape a 1D array of 16 elements into (8, 2) and then back to (4, 4), printing shape and strides at each step.
Write a NumPy program to verify that reshaping a 1D array into different 2D shapes retains the same data pointer.
Write a NumPy program to perform sequential reshaping on a 1D array and display how the strides change with each transformation.
Write a NumPy program to reshape a 1D array into a 2D array, modify one shape, and check if the memory ordering remains consistent.

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