Creating and reshaping a 2D NumPy array

Last update on March 26 2025 13:14:39 (UTC/GMT +8 hours)

18. 2D to 3D Reshape Variation

Write a NumPy program that creates a 2D array of shape (4, 6), then reshape it into a 3D array of shape (2, 2, 6). Print the original and reshaped arrays.

Sample Solution:

Python Code:

import numpy as np

# Step 1: Create a 2D array of shape (4, 6)
original_2d_array = np.random.rand(4, 6)
print("Original 2D array:\n", original_2d_array)

# Step 2: Reshape the 2D array into a 3D array of shape (2, 2, 6)
reshaped_3d_array = original_2d_array.reshape(2, 2, 6)
print("\nReshaped 3D array:\n", reshaped_3d_array)

Output:

Original 2D array:
 [[0.62709246 0.23292313 0.94462683 0.96736515 0.61750314 0.11905439]
 [0.35378285 0.03013207 0.95206969 0.38529313 0.83720405 0.55076462]
 [0.04496562 0.16134742 0.49377059 0.23158711 0.92115743 0.55099414]
 [0.50158092 0.39983701 0.57911658 0.48010662 0.55052127 0.29038728]]

Reshaped 3D array:
 [[[0.62709246 0.23292313 0.94462683 0.96736515 0.61750314 0.11905439]
  [0.35378285 0.03013207 0.95206969 0.38529313 0.83720405 0.55076462]]

 [[0.04496562 0.16134742 0.49377059 0.23158711 0.92115743 0.55099414]
  [0.50158092 0.39983701 0.57911658 0.48010662 0.55052127 0.29038728]]]

Explanation:

• Create a 2D array: A 2D array of shape (4, 6) is created using np.random.rand().
• Reshape to 3D: The 2D array is reshaped into a 3D array with shape (2, 2, 6).

For more Practice: Solve these Related Problems:

• Write a NumPy program to reshape a 2D array into two different 3D shapes and compare the element ordering in each case.
• Write a NumPy program to verify that reshaping a 2D array into 3D preserves element order by flattening both arrays.
• Write a NumPy program to reshape a 2D array into a 3D array and then apply an axis permutation to analyze the impact on strides.
• Write a NumPy program to create a 2D array, reshape it into a 3D array, and then apply a mathematical function to verify data consistency.

Python-Numpy Code Editor:

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