NumPy: Construct an array by repeating

Last update on March 24 2025 13:39:51 (UTC/GMT +8 hours)

Repeat Array Entirely

Write a NumPy program to construct an array by repeating.
Sample array: [1, 2, 3, 4]

Pictorial Presentation:

Sample Solution:

Python Code:

# Importing the NumPy library with an alias 'np'
import numpy as np

# Creating an original array
a = [1, 2, 3, 4]
print("Original array")
print(a)

# Repeating the original array two times using np.tile
print("Repeating 2 times")
x = np.tile(a, 2)
print(x)

# Repeating the original array three times using np.tile
print("Repeating 3 times")
x = np.tile(a, 3)
print(x)

Sample Output:

Original array                                                         
[1, 2, 3, 4]                                                           
Repeating 2 times                                                      
[1 2 3 4 1 2 3 4]                                                      
Repeating 3 times                                                      
[1 2 3 4 1 2 3 4 1 2 3 4]

Explanation:

In the above code -

a = [1, 2, 3, 4]: A list a is defined with four elements.

x = np.tile(a, 2): np.tile repeats the given list a 2 times along its first axis. In this case, a is repeated twice, creating a new NumPy array: [1, 2, 3, 4, 1, 2, 3, 4].

x = np.tile(a, 3): np.tile repeats the given list a 3 times along its first axis. In this case, a is repeated thrice, creating a new NumPy array: [1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4].

For more Practice: Solve these Related Problems:

• Repeat a one-dimensional array using np.tile and validate that its shape is doubled or tripled as expected.
• Create a function to repeat an array and then reshape the repeated output into a matrix.
• Verify that the sum of a repeated array equals the original array’s sum multiplied by the number of repetitions.
• Repeat an array entirely and compare the result with manual concatenation of the original array.

Python-Numpy Code Editor: