How to create and flatten a 2D NumPy array using ravel()?

Last update on April 29 2025 12:56:02 (UTC/GMT +8 hours)

3. 2D Array Flatten with Ravel

Write a NumPy program to create a 2D array of shape (4, 4), then use ravel() to flatten it and print the result.

Sample Solution:

Python Code:

import numpy as np

# Create a 2D array of shape (4, 4)
array_2d = np.array([[1, 2, 3, 4],
                     [5, 6, 7, 8],
                     [9, 10, 11, 12],
                     [13, 14, 15, 16]])

# Use ravel() to flatten the 2D array
flattened_array = array_2d.ravel()

# Print the flattened array
print(flattened_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 which provides support for large multi-dimensional arrays and matrices.
Create a 2D array: We create a 2D array array_2d of shape (4, 4) using np.array().
Flatten the array: We use the ravel() method to flatten array_2d into a 1D array, stored in flattened_array.
Print the result: Finally, we print the flattened array.

For more Practice: Solve these Related Problems:

Write a NumPy program to flatten a 2D array using ravel() and then compare the result with flatten() to illustrate differences in views and copies.
Write a NumPy program to create a 2D array and use ravel() with both 'C' and 'F' order, then compare the flattened outputs.
Write a NumPy program to modify the flattened array returned by ravel() and show that the original 2D array reflects these changes.
Write a NumPy program to apply ravel() on a sliced section of a 2D array and print both the slice and its flattened version.

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